Good morning everybody. I am Deepak Patak. I have been a teacher here in IIT for last 40 years. And this particular initiative of engaging teachers in specific subjects on a very large scale in the country was conceived by us about 5 years ago. We started this distance education activities about 10 years ago in IIT and we believed that it is not just the creation of e-contents which are meaningful. They could at best be supplementary to our teaching learning efforts, but since the major teaching learning would happen, continue to happen on a model of a classroom, we thought we could emulate the classroom model for scaling up our interaction with teachers. And that is how we perceived of this particular model where we have 30, 40 remote centers and we request participating teachers to come at each one of the remote centers and interact with us. As you would have seen in the last two weeks, the model involves expert faculty members giving talks from one place which happens today to be IIT Bombay. It could be any other place in fact in future and the participants attend these lectures from various remote centers, but they are engaged again in some kind of a classroom group environment in the afternoons doing their labs, doing their assignments, doing their tutorials because at the end of the day teaching and learning is people's game. It is not just an electronic game to be handled by ICT. Technology has to be subservient to our own methodology and our own practices which is what we have attempted to do. And I hope you have all benefited from this particular course. I would like to use this opportunity to share some of my thoughts on the general teaching learning environment in our professional institutions. And you would endorse this because you would be seeing this in actual happening every day of your life when you teach courses to your students in different colleges. First of all, you would all agree that in the last 20 years, the number of colleges in the country have increased exponentially and they continue to increase exponentially. In most standard and conventional academic infrastructure, the faculty members are generally expected to have a PhD degree even though they are teaching a first year B or a B Tech student. Why? Because we believe that research and teaching have to go hand in hand. Any person who is familiar with the advanced concepts and have worked on some research problem, we believe is better place to engage even first year students in clarifying basic concepts. Unfortunately, because of the unprecedented growth of the number of colleges and the inability of the nation to build an equivalent infrastructure to provide PhD and M Tech level courses for prospective teachers, we have a serious situation where a large number of our faculty members teaching in engineering colleges do not have a PhD or many do not even have a master's degree. The fault is not theirs, the fault is the inability of the nation to provide opportunities. For this reason that we decided to scale up our efforts in engaging teachers, we are beginning with introductory courses which are taught at the core engineering level, but we will certainly carry forward this initiative and engage teachers in advanced courses and even in research courses in coming years. Only yesterday I had attended a meeting, attended a meeting at ministry. The ministry is aware of the advantages of this kind of scaled engagement and they have asked us to prepare plans for more advanced courses in future years to come. I would still suggest that the large number of faculty colleagues who are participating in this particular program should continue vigorously to do their own research work in whatever little fashion that they could at their own place of work. Research is not done only in while you are doing PhD. PhD is merely a mindset indicator which you attend after spending a few years on solving some research problem, but that mindset attainment is a difficult task that has to be pursued by every individual. And I hope, I hold in fact the opinion that good research can be carried out at any place of course, the infrastructure, the environment etcetera, etcetera have to be conducive, but the most important thing is the commitment of an individual to say that no matter how hectic my life is, no matter how many courses I have to teach, no matter how many students mark sheet, answer books I have to evaluate, I will always find sometime every week, maybe two hours, maybe four hours to do some hardcore thinking on some hard problem and come up with my research ideas. I will do some reading of research papers. I may not have research journals available in my college, but I will use internet to access the recent research work that I can see published. I will tell you that I have found even Wikipedia to be a great source of technical information on absolutely the state of art and current technical subjects. I would submit that our teacher colleagues would do very well to occasionally look at the technical contents on Wikipedia and enrich themselves. I will also suggest that we have broken the academics into various fields. Let us consider the engineering discipline. We have in engineering civil engineering, mechanical engineering, electrical engineering, computer science, metallurgical engineering and so on. Within mechanical engineering, we now have separate fields of studies because of the growing body of the knowledge. What we forget is that these nomenclatures that we have created and the corresponding division of students into different branches, teachers into different branches that we have done. We have done this primarily to address a very fast growing body of knowledge in everything. It is not humanly possible for everybody to know everything in everything, but I would also submit that knowledge per se cannot be bound or cannot be broken into such siloed. You have seen, I have noticed that in the interaction the last half an hour that I have witnessed, I have seen for example, people truly being concerned about differences and similarities or differences and interactive effects between say nuclear radiation and the heat transfer. This was just one example, but I would like to say that because the siloed that we have built, the kind of teaching that we do itself is getting affected and we are increasingly becoming victims of our own divisions. For example, today I find that students of electrical engineering are rarely convinced that they must understand the basics of thermodynamics and heat transfer because they think they have nothing to do with it. The worst lot is probably my own discipline, the computer science students, they do genuinely believe that they will have nothing to do with heat transfer because they are unlikely to encounter it in their lives. This is very sad. In the old days, when the engine courses used to be of 5 years duration, I remember when I did my engineering, I was to become an electrical engineer, but there was no solace. I had to do a course in surveying, I had to do a course in heat engines because it was believed that the fundamental engineering principles have to be understood by every engineer no matter what brand or what branch one qualifies it. We were told time and again that whatever with the nomenclature you might give, mechanical engineering is mother of all engineering. I think that spirit is now completely lost. I see it increasingly in engineering colleges when I visit that not only students of other disciplines, but even teachers of other disciplines have started maintaining a respectful distance from these basic concepts in engineering. I think this is very contraindicated for a proper holistic development of engineering education in the country. While of course the teachers and students of other disciplines are responsible for this, but I would submit that the initiative has to be taken by our colleagues in the mechanical engineering department who are perhaps busy teaching the core courses in mechanical engineering to all the students and some courses only to mechanical engineering students. It is there that I will request my colleague teachers to constantly keep coming up with examples which will perhaps be of interest to students who are pursuing other disciplines. I will give you one example. This happened in my own lab in the software lab about 25, 30 years or 25 years ago. Early 80s when the personal computer had come out in the world for the first time and the personal computer model that was given to us for evaluation was a vertical model instead of a horizontal model. In that particular PC, I was staggering to see when it was opened up that the power supply unit which is a very heavy portion of the entire PC was sitting on the top rather than at the bottom and the way the horizontal layout was converted into a vertical layout by simply resetting the physical shape. The fan which was supposed to take out the heat was kept at the bottom and the cards the electronic cards were actually obstructing the flow of that heat and I asked the students who were working on that PC saying do not you think there is something wrong with this PC. They moved around it one circle and they said no sir it has been working fine for last three days and that was because it was in an air conditioned environment and I said what about the center of gravity. Some smart student at least picked that up and said yes sir the power supply unit should be at the bottom and not at the top. Then I said and what about exchange of heat then they were completely flabbergasted. They were computerized students of IIT Bombay they said what about heat sir. I said how is the heat transfer being affected by changing the geometry of your entire configuration and then one fellow thought for 10 seconds and gave a very bright answer. He said oh that is a mechanical engineering problem. What he was basically telling me is that as a computer science student he will have nothing to do with the heat transfer problem because that is a mechanical engineering problem. I was very upset with this I shared this with my colleague Professor Gayathonde who actually put together an experimental setup for an m tech project where he put the entire PC in some kind of prospect cover put about 14 or 15 sensors and started measuring the temperature at each point in that PC configuration. Why I recite this example is to suggest that there is nothing like heat transfer or for that matter any particular topic being completely isolated from rest of the world. And every practicing engineer has to be familiar with fundamental aspects of engineering be that in any case. Even to the mechanical engineers I would submit that many times we miss out on the associated activities because either we have not studied them or they are not considered part of our standard syllabus. Let me give you a couple of examples you would all have seen these fireflies flying around fireflies generate very nice sparks of light. The standard mechanism of generating light in our engineering is known to be transfer heat into light that is how we see the normal bulk. If fireflies were to generate light from such intensive heat generation they would burn and yet they would not burn why they use something called bioluminescence. Consider another aspect consider manufacturing of ammonia we do that routinely in chemical processes these are all high temperature high pressure processes. And yet the nitrogen acquisition by plants is done at normal temperatures and pressures we call this nitrogen fixing. Do we study any one of these phenomena we do not because they are traditionally considered to be part of biology or life sciences. And since life sciences and biology is not part of our syllabus we do not bother about. I would like to comment on the notion of a syllabus that is because almost all teaching seems to be governed by our syllabi and all learning seems to be governed by examination pattern. I think these two have been detrimental to the growth of proper quality in our engineering education. Sadly we may not be able to do much about it. We keep saying that in IIT Bombay there is a syllabus written and approved by the senate. But when my colleague teachers teach their courses I do not think they bound themselves by that syllabus. Why because they understand that syllabus is a reflection of what knowledge has been accumulated in the past by experts working in that field. They are aware that knowledge will continue to grow. They are also aware that the challenges and problems faced by the students when they pass out of the college and go out in the field will be completely new and different and which will require probably new knowledge or new approach to be generated by them on the field when they approach that problem. And therefore they properly understand that syllabus is at best a guideline to reflect on what knowledge has been accumulated. But when we teach we are preparing our students for the future and therefore if any learning specially the ability to think through problems is limited only by what has been achieved in the past which is what syllabus represented syllabus represents we would not be able to train our students to solve real life problems. And that is the reason when at least in the IIT system we routinely take pangas with syllabus. That is the reason why every teacher when he or she teaches a course whatever he or she teaches becomes the syllabus. That facility and freedom may not be available to a large number of our teacher colleagues because of the university system where the syllabus itself has been defined several years ago and is very rarely changed. However and this is my submission I would suggest that my teacher colleagues who are attending this course should attempt to do two things. One to try and influence their universities and boards to keep changing the syllabus more frequently. And second this is more important in their own teaching could they not find out avenues where they could exceed the syllabus. Where they could excite the students by telling them about the recent happening which have not been captured by the syllabus. But which are related to some basic concepts and therefore they are relevant to the thinking of the students even if they are doing some basic course. You will have to teach as per the syllabus and the exam pattern because that unfortunately is what the students will gobble up. But I would submit that there would be a few students in your class and every class there will be such few students who are willing to think differently, who are willing to think beyond the boundaries of the syllabus. Can you not for example announce in a semester that look you will hold let us say every Sunday morning a two hour session for discussing only the recent advances in the field. I am aware that not all the students of your class will be interested in coming to such Sunday morning session. But I have seen several amongst you doing similar initiatives across the country in different places and I have seen that out of a class of 60 to 100 students at least 10 to 15 students will come forward and attend this. Those 10 to 15 students are important because they are like you willing to look at things beyond the syllabus. They are the ones who are likely to make a difference to themselves to the field of studies to the field of their activities and ultimately to the nation. I would submit that there is a lot of merit in attempting to do this. Set up a group called problem solvers group. This problem solvers group does not look at normal problem. It looks at hard problem which are never asked in an examination, but attempting to solve them would create a whole lot of new thinking in the minds of students and who knows even amongst you. I have seen I have been a teacher here for 40 years.  Some observation or the other by some student will give me new idea something which I have not thought of. Why do you think that this should not happen in every college where students are there? Out of 100 students I can tell you that you will find in every college at least 20 students who think differently unfortunately because of our responsibility to take all 100 students and get them at least to pass the course we sometimes miss out on these 20 or 10 or 4 students. I would submit that just as it is important to take care of very weak students in the class. It is equally or perhaps more important to take care of those 4, 5, 8, 10 students who are different, who are the leaders and who are the possible thinkers to excite them to think, to excite them to solve hard problems is also a responsibility that each of us as a teacher should fulfill. Here is my submission that while we attempt to create this kind of environment and this kind of empowerment to all teachers let this empowerment to go further than just doing the mundane teaching for the course which are required to do as per your university syllabus and go beyond that and create such groups. You may have initially a group within your own college, but as a part of this project itself we are trying to create a open source site based on JUMLA this portal would probably launch in few months time, but all the material that you contribute all the material that my colleague teachers have created for this course the entire teaching learning material in terms of slides, the complete video recorded lectures plus the assignment, the tutorials, the labs etcetera etcetera that you have gone through will be kept on that open source portal. That idea is that lakhs of students and thousands of other teacher colleagues who have not benefited from this live interaction could at least see what all happened and excess the knowledge that was created. Please remember knowledge is not created only by the slides and the problem set that you do, knowledge is actually learnt by observing the interaction that happens. That is the reason why I did not interrupt the interaction that was happening sometime ago. I am sure that every day there would have been an interaction of this type. I firmly believe that it is that interaction which creates additional thinking in the minds of people who observe that interaction. So, as you will notice from some centers some one person was asking a question and one person was answering it, but the activity of asking that question and the activity of that question getting answered creates an equivalent thermal conduction, convection and radiation in the minds of all others who are attending. Why I could feel that I was benefiting tremendously from the interaction that was happening there. It is this interaction which we propose to capture in this audio visual recording and also keep that interaction available on the model so that other people could benefit. It is towards this end that I suggest that whatever submissions that you will make after the workshop that will also be made part of the open source contents here. If at all you succeed in building such problem solver group in your own area, in your own college, the interactive portal that will be setting up two months later will permit any such creation of knowledge, any such discussion in the problem solving group that you have in individual colleges could very well become part of the larger portal and that portal could create eventually larger collaborative groups which will attempt thinking solving larger problems, difficult problems and that would eventually see into the learning and teaching at every college that happens in everything that is the larger ambition. Innovative thinking is not the property of only those people who are experts in that field. I will give you one example of how innovative thinking changed something since it is related to heat transfer. You will recall early days of steam engines. The steam engines and the early boilers used to be very conventional boilers. Those of you have seen in old days there used to be a bomba for heating water in every house.  That was actually the model used in the earliest boilers even those which were employed in steam engines. The leading steam engine company had a person who used to always wonder whether that is the best and the most efficient way of heating water and generating steam. So, he for the first time suggested why do not you attempt instead of letting the hot gases flow only through a single central pipe. Why do not you push it through multiple pipes so that they will heat a larger amount of water and you would have perhaps more efficient steam generation. This was in fact attempted for the first time by the British company which led to the first design of multi-tubular boilers. Till then there used to be a single tube. Do you know who was the person who suggested this? He was not an engineer. He was not an expert even in those days on heat transfer and steam engines. He was the company secretary of that company who used to handle accounts for that company. It so happened that that was a small company and any design activities etcetera etcetera used to happen in the same physical premises where the accounting people will also say. He was just interested and curious. Why I recite this example is because please do not believe that innovations for solving problems will necessarily come only from the experts in that field. Innovations could come from anybody anywhere because innovation is nothing to do with a specific where it has to do much more with the ability to think differently to solve a problem. I would like to suggest that it is because of this reason that you should not only inculcate ability to do innovative thinking amongst your students but try to do the same in students of other disciplines and colleague teachers of other disciplines as well. I would only say that in this 21st century where clearly the economic developments all across the world suggest that the fulcrum of development is moving from the western world to the Asian world again. We have seen that in spite of the turbulence that you see elsewhere India and China are growing at rates which are not imaginable by the previous standards and the next 10, 20, 30 years we will see unprecedented growth in both the large India and China the two countries but as well in other Asian markets. Now when the growth happens when the economic growth happens it has to be matched by the growth in creation of intellectual wealth because that is what will further fire and fuel this growth and this has to happen primarily to our through our professional courses primarily through our engineering courses. You will see product companies you will see service companies coming up in this country but you still have to see a whole lot of original ideas coming and getting into the future products. That is where I would suggest that out of 100 students that you have while you do pay attention to all 100 you do help the weak students to learn as much they could to pass the courses at least but please pay special attention to those 5, 8, 10 students that you will find who think differently who think much beyond the syllabus and try to help them and in the process create an environment in every college such that the college gets known for its ability to solve harder problems. The college gets known to become a higher quality educational institution I would think that is the joint responsibility that all of us have. There are many things that I would like to share some day perhaps I will write again on the portal a block spot where I will keep exchanging my ideas with you but at this juncture I will only submit that the feedback tells me from for so far that most of you have enjoyed and benefited from this course. Please pass on this message to all your other colleagues in your own colleges. I will just mention a future workshop that we are planning this workshop will not be for 1000 teachers but this will be for 10,000 teachers and we wish to conduct this workshop from 200 remote centers. This will be a shorter workshop of 5 days duration and this workshop will be on what we call research methodology. This is not related to any particular branch like mechanical civil or something any teacher doing either a masters program or pursuing a PhD or learning to pursue any one of these would benefit from this workshop because here we will discuss what is research what motivates one to do research including the desire to acquire a PhD so that I can get promotion. What is the methodology that needs to be followed? There is a professor in mechanical in IIT Madras professor Karmalkar who had given a talk on the research methodology to our research scholars of few years ago our colleague professor Patra Dhan head of the chemical engine department had facilitated that and he had put all those lecture contents in open source. We are trying to fashion this course unfortunately we do not have a budget to conduct a one week program for 10,000 teachers. This program will therefore be conducted in a very peculiar way in so far as budgeting is concerned in the first time we will be attempting to run this program but we believe that such a program would be important and very useful for the teaching fraternity. We would like to know there is a question that my colleague Kalpana has put in your feedback whether you would be interested in attending such a course. If you would be then this would be the first time that this country will show to itself and to the world that we the teachers believe that learning these kind of things are important for us and we are willing to do this at our own cost if it is necessary. So, that is my ambition that all of us would contribute to the better and higher quality of learning and teaching that should happen in our engineering institutions because with all said and done it is the engineering institutions which will produce the tomorrows wealth creators who are all going to depend upon technology and the engineering to generate wealth tomorrow. With this I will conclude my talk. I must use this opportunity to thank a set of people who have helped in the proper conduct and the fruitful conclusion of this two week workshop. To begin with I would like to thank my colleagues here. Let me tell you that the interaction that you had with them for two weeks is what you have seen but what I have seen is the enormous amount of effort that they have taken for past several months to work out on the contents and the learning material for this course. So, thank you very much and I really appreciate your activities. Let me honor them by giving them a token of our love and affection and thanks without them this course would not have been possible. So, thank you for everything that you did. I am sure that they have with them very capable teaching assistants as we call them to help them create this. Equally importantly I would like to thank the coordinators from all the remote centers. This again may not be very well known to all the participating teachers but these coordinators at the respective center have spent a good one full week physically coming over to IIT, finding time from their regular schedule and they spent that one week together with my colleagues here. They decided what should be the most meaningful syllabus for this course, how it can be doubted into the existing syllabi and the examination patterns of the universities and yet should attempt to address the style of teaching, the style of solving hard problems that is practiced in IIT's and some of the better institutions. So, this there has been a lot of work my thanks to the remote center coordinators, my thanks also to a large number of supporting staff and faculty colleagues at the remote centers without whom I am sure that the remote centers would not have been able to arrange everything that they did for the workshop participants. In exactly the similar fashion at IIT Bombay itself we have a large team. We have some of them present here, could we have our senior managers here Dr. Mukta Atre Jaya who is our finance minister who handles all the finance related thing and Kalpana who handles our contents. We have Sajjan who handles the entire audio visual setup you can see some of his team members here. I take this opportunity to thank all of them. I must also thank people who are absent, but who have provided the basic technology and that is the A-view product that we use which was developed by Amruta. I can see Mahendra Parmar and there are so many people here actually my colleague managers have a team of about 50 people doing the technology development and the administration that they handle. So I take this opportunity to thank them profusely. I also would like to take the opportunity to thank the issued administration without an active support primarily by the office of DNRND and equally importantly the departments which participate in teaching of these courses in this particular case the mechanical engineering department which has taken a lead by the way I must say that apart from electrical engineering and mechanical engineering we are yet trying to convince other colleagues in other disciplines to come forward and give courses. So my thanks to these department colleagues as well. With this I would declare this course formally closed informally of course it will close after you finish your quiz and after you listen to the assignment that is stored for you for the post workshop. Thank you one and all and all the best for your future endeavors in better quality teaching. God bless you.


Hello and welcome to this presentation of the STM32 digital filter for Sigma Delta Modulator's interface. The features of this interface, which behaves like ADC with external analog part and configurable speed versus resolution ratio, will be described. The DF-STM peripheral is a new digital peripheral inside the STM32 products. Its behavior is finally like standard ADC with the analog part outside the microcontroller. The main benefit is to move the analog part outside the microcontroller and to propose an internal digital part with a wide range of features. The DF-STM represents the digital part which is connected to the analog part by fast serial interface. The external analog part is usually a Sigma Delta Modulator offered by a wide range of vendors. This feature offers the possibility to choose a specific analog part according to the user's needs. Like galvanic isolation for motor control or metering applications, a low noise and high precision analog part for sensor data acquisition applications, or a cheap analog part for price sensitive applications. Finally, the analog part provides digitized data for DF-STM. The digital part represented by the DF-STM peripheral performs a digital signal processing from external data. Therefore, it offers a scalable ratio solution between speed and resolution, but also an additional functionality integrated in standard built-in ADC like analog watchdogs, injected and regular conversions, flexible triggering system, brake signal generation, and extreme detector. Digital MEMS microphones providing a PDM output data format can be directly connected to DF-STM, which can directly process the audio signal. The DF-STM is able to process the external serial data and also the internal parallel 16-bit data transfer provided by the CPU or DMA from memory. The DF-STM was developed due to a need for a Sigma Delta ADC with scalable speed versus resolution. More than 16-bit accuracy inside a microcontroller is a problem because of noise from the digital part. The solution is to move the analog part outside the microcontroller. The speed versus resolution ratio setting is a task for the internal digital part, which is the digital filter in the hardware. Although it behaves like a complete analog to digital converter with an external analog front end, the DF-STM is purely digital with its analog part outside the microcontroller. The DF-STM integrated inside STM32 products provides the digital part of the complete Sigma Delta ADC with an external analog part, which is the Sigma Delta modulator. Both parts are connected through the serial interface, which provides a one-bit Sigma Delta STREAM. The average value of this STREAM represents the analog value on input. Applications can benefit from the easy connection. Just one or two wires are needed. Thanks to the analog being located outside the microcontroller, there is less noise caused by the microcontroller. The balance between speed and resolution according to application needs can be set by configuring the digital filter. Transceivers provide the serial connection to the external Sigma Delta modulator. They support serial connections with configurable protocols, SPI or Manchester, and configurable parameters. Their functions will be explained later in detail. Transceivers also have support for internal 16-bit parallel data inputs, which will be written to the DF-STM input data registers by the CPU or DMA and optionally by the internal ADCs. For STM32, L45X, 46X, 49X, 4AX devices only. Filters are the core of the DF-STM function. They perform one-bit STREAM filtering to provide higher output resolution at lower speeds. There is an additional integrator behind the digital filter, which provides additional data averaging. Applications can be designed with various types of Sigma Delta modulators from various vendors. The parallel data input feature can perform post-processing of any internal data, for example internal ADC STREAMs, audio data filtering, etc. There is a list of additional functions, which will be explained later in detail. The entire digital filter for Sigma Delta modulators interface consists of 8 serial transceivers, 4 sync filter parts and integrators, 4 output data units, 4 analog watch dogs, 8 short circuit detectors, 4 extreme detectors, and 8 parallel data input registers. For STM32, L45X, 46X devices, the configuration is only one-half, 4 transceivers and 2 filters and integrators. The STM32, L45X, 46X, 49X, 4AX devices feature parallel inputs from internal ADCs. Serial transceivers provide the connection to the external Sigma Delta modulator. SPI mode works up to 20 MHz or the DF-STM clock divided by 4. There are configurable options, including sampling edge selection, data rate measurement, and clock presence monitoring. One-wire Manchester-coded mode, where clock is recovered from the data, works up to 10 MHz or DF-STM clock divided by 6. A synchronization detection feature is also available in Manchester mode. Manchester mode also offers the lowest system cost in case of optical isolation to the Sigma Delta modulator, then only one single isolator per input channel is necessary. The DF-STM clock features a clock output signal to drive the Sigma Delta modulator. It can be used as a source for the SPI clock input by internal interconnection in order to save external pins. The clock output has an adjustable division factor and can be driven either from the system clock or from the fine-tuned audio PLL clock. Parallel transceivers provide parallel inputs from internal data sources, for example, from memory buffers. Parallel inputs are usually used for fast hardware filtering of internal data from the ADC or any data collected from a communication peripheral. Data can be written to the DF-STM parallel input registers by the CPU or DMA configured in memory-to-memory transfer mode. DF-STM32L45X46X49X4AX devices, the internal analog-to-digital converters provide parallel data directly to the DF-STM parallel input registers. The digital filter averages the one-bit input data stream from the Sigma Delta modulator into a higher resolution, but with a slower data output. The digital filter is sync-X type with an order from one to five. A fast sync type filter is also available for selection. The oversampling ratio means how many samples will be averaged in a single filter run. The oversampling ratio can be selected in a wide range from one to 1024. Not all combinations of filter order and oversampling ratios are available because in higher filter orders, the oversampling ratio must be reduced to not overflow the 31-bit data width, which is the internal filter resolution. The integrator unit performs additional simple averaging of data provided by the digital filter. It provides just a simple summing of the data coming from the digital filter. The number of samples to be summed can be set from one to 256. The correct configuration must take care that the final data length fits into the 31-bit width, which is the resolution of the internal integrator. The width of the data coming from the digital filter must also be taken into account. The output data unit adjusts the final data before they are written to the final data register. An offset value that will be automatically subtracted from the data result for each channel can be defined in the offset register. The correct offset values are determined using the calibration procedure. This calibration procedure should be programmed in user firmware and depends on the type of Sigma Delta modulator connected and application needs. The maximum resolution of the final output data register is 24-bits, but the internal resolution can go up to 31-bits. But certain applications have their own constraints, for example, 8, 12, 16, or 24-bit data resolution. Therefore, there is an option to perform a right-bit shift of the data to provide the final data result with the required width and not overflow the 24-bit width of the final data register. Right-bit shift is configurable from 0 to 31-bits. The final resolution then depends on the digital filter and integrator settings, as well as the right-bit shift option. The analog watchdog monitors sampled analog data to see if it remains within the selected high and low threshold values. The input to the analog watchdog function can come from the result of the final converted data or directly from the input serial channels through a configurable filter. If data exceeds the allowed boundaries, an interrupt can be invoked or a break signal generated. If an interrupt is invoked, the software decides about the next actions. If a break signal is generated, this break signal can perform a safety function directly by hardware. For example, stop a timer which controls the motor. There are separate high and low threshold levels and separate flags for each threshold to know if a threshold has been reached. The analog watchdog can monitor two types of data. The first type is standard output data, as with a standard ADC. The second type of data can come from serial transceivers through configurable dedicated filters. This second option allows you to select faster signal monitoring when the required speed and resolution is set by the filter parameters. Each serial channel watchdog filter is configurable from 1 to 3 and its oversampling ratio in range from 1 to 32. The data from these watchdog filters can also be read by user firmware. The short circuit detector monitors input serial channels for a saturation state. When an input signal is saturated, it means that it is outside the allowed measurement range and therefore there is an overflow or underflow of the signal. When measuring current, this event usually detects an overcurrent or short circuit or an overvoltage when measuring the voltage. Detection of input signal saturation is based on monitoring the input serial data stream coming from the Sigma Delta converter and watching if there is a consecutive set of ones or zeros for a relatively long time. This maximum saturated time can be set in the range from 1 to 256 of sampled input data which will have the same value, zero samples or one samples. Monitoring is performed independently from the main conversion. The main conversion can perform conversion from another channel or can also be stopped. All input channels can be monitored in parallel with their own saturated time setting. When a saturation event is detected, an interrupt can be invoked or a break signal generated. Then, just as with the analog watchdog, the software decides the following actions or the hardware break signal can perform a safety function without any software latency. For example, it can stop the timer which controls the motor in the event a short circuit is detected. The extremes detector monitors output results and stores the extreme values into minimum and maximum registers as well as the associated channel number. Monitoring of data for extremes is only performed on selected channels to ensure that channels do not mix different input levels. Stored extreme values are refreshed each time the values are read in the register. Regular conversions have less priority and can be interrupted by an injected conversion. If the regular conversion was interrupted by an injected conversion, it is restarted once the injected conversion is finished and this interruption is indicated as a flag for this delayed regular conversion. Regular conversions can be launched only by software and there is no scan mode available. Regular conversions can run in continuous mode in which there is no channel switching and they can be performed in fast mode without filter refill. Regular conversions are used for measurements for which timing is not critical. For example, when measuring temperatures or slow signals. Regular conversions are also typically used for continuous conversions from one channel only. For example, audio or energy measurement applications. Injected conversions have high priority. They can interrupt regular conversions immediately and start just after being triggered. Any of the input channels can be assigned into an injected channels group. There are two modes of conversion behavior. Scan mode and single mode. In scan injected mode, all channels from the injected channels group are converted starting from the lowest to the highest channel number in a group when a trigger occurs. In single injected mode, only one channel from the injected channel group is converted and the next channel from the injected group is selected for the next conversion. The next trigger will start this next channel conversion and another higher channel from the group is selected. Injected conversions can be launched by software or by hardware from timers or an external pin. Injected conversions cannot run in continuous mode, but this mode can be emulated using a periodic timer trigger. Those modes make it possible to choose the correct conversion mode according to application requirements. The MEMS microphone provides a pulse density modulated or PDM data signal whose format is theoretically like the Sigma Delta bit stream from the Sigma Delta modulator. The MEMS microphone has stereo support if two microphones are connected in parallel with common data and clock signals. Rising clock edge samples left audio data. Falling clock edge samples right audio data. Implementation into DFSDM transceivers requires this configuration. Channel zero uses redirection input from channel one. Channel one uses direct input. Channel data left versus right are separated inside by selecting either the rising or falling edge in the SPI configuration of channels. The clock signal is provided by the DFSDM clock output because the MEMS microphones are slaves and need an external clock for data sampling and communication. A set of interrupts related to DFSDM events has been implemented to increase CPU performance. This table lists all of the DFSDM interrupt sources. End of conversion events with separate flags for regular and injected conversions. Data overrun events with separate flags for regular and injected conversions. Analog watchdog events. Short circuit detector events. And channel clock absence event. To decrease the CPU intervention, conversions can be transferred into memory using a DMA transfer. DMA transfers for injected and regular conversions can be enabled separately. The direct memory access controller, or DMA, can also be used as a method for fast data transfers into parallel data registers. In this case, the parallel data are transferred from the memory buffer into the parallel data register by using the DMA. The DMA should therefore be configured from memory to memory transfer mode where the target address is the address of the parallel input data register. The DFSDM peripheral can be active only in run and sleep modes. In all other low power modes, including stop, standby, and shutdown modes, the DFSDM must be disabled. DFSDM performance depends on the maximum allowed input data rate because each input data sample causes the next digital filter operation. The DFSDM allows operation at a maximum input data rate of 20 MHz in SPI mode or 10 MHz in Manchester mode. Parallel data inputs have the same performance, so parallel data can be put into DFSDM at full 20 MHz speed using either the CPU or DMA. Applications benefit from DFSDM high speed processing, which now supports all existing Sigma Delta modulator speeds. The STM32L4 evaluation board can be used to run two simple application examples to help you explore the digital filter for Sigma Delta modulators interface. The first example is a demonstration of the MEMS microphone directly connected to the DFSDM peripheral. Data from the microphone are processed by DFSDM with correct filter settings and then collected into a memory buffer using regular continuous conversions and the DMA. Recorded data from the microphone are then immediately sent by the DMA from this buffer to the I2S peripheral and played by headphones. The second example is a PT100 thermometer which uses an external STPMS2 Sigma Delta modulator which monitors two channels. One channel senses the voltage and the second one senses the current on the PT100 sensor. Both channels are sampled using timer triggered injected conversions in scan mode. Software then computes the PT100 resistance from collected data and finally the temperature. This schematic shows an example of the PT100 thermometer. Here you can see how the STPMS2 device senses the voltage and current over the PT100 sensor. Sensed data are sent from the STPMS2 device to the DFSDM peripheral through the serial interface. This example shows a typical one phase electricity meter design using an STPMS2 device and STM32 microcontroller. The STPMS2 is a dual channel Sigma Delta modulator designed for electricity meter applications. It has voltage and current channel inputs. The current channel features a programmable gain amplifier to cover a wide range of measured currents. Sampled one bit data are sent by the serial interface to the host device which here is the DFSDM interface. Both voltage and current one bit data samples are sent on the same data wire but the voltage is sampled on the rising clock edge while the current is sampled on the falling clock edge. The clock is provided by the DFSDM and can run up to 4 MHz. The DFSDM then processes the voltage and current channel one bit data streams into output data with a higher resolution and slower data rate. Finally the firmware uses FFT analysis to calculate the electric power and energy from the current and voltage samples. This example shows a three phase electricity meter design using shunt resistors for sensing current. There is no need to use expensive current transformers. Voltages are sensed by three resistor dividers and external Sigma Delta modulators. Currents are sensed by three shunt resistors. Each shunt resistor voltage is sensed by one Sigma Delta modulator. Because each Sigma Delta modulator operates at a high phase voltage galvanic isolation is used for data transfers into the DFSDM. If the Sigma Delta modulator uses the Manchester coated serial protocol format and has an internal clock source only one isolator per phase is necessary. If the Sigma Delta modulator uses the SPI serial format two isolators per phase are necessary. Each Sigma Delta modulator is powered from a separate DC supply voltage. This example is related to a three phase industrial high voltage high current motor drive where floating shunts and galvanic isolation are standard. A single reading channel is represented here while in the application two or three channels are used for the current in addition to two or three channels for the voltage. The currents are usually measured simultaneously by three DFSDM channels while the voltage can be measured sequentially with the same DSFDM channel. The same bit stream is processed three times. First for high accuracy measurements the main filter is used over a relatively long time. This measurement is done synchronously with a PWM period to avoid switching noise and have regular samples. Second, the watchdog channel uses the same bit stream with its own lower order filter continuously monitors the signals and invokes an interrupt in case of overload with medium reaction time. And third, the short circuit detector is used to detect very rapidly a modulator saturation continuous series of zeros or ones with a programmable length and automatically disables the PWM generator through a dedicated DFSDM to the timer interconnection by a break signal. The peripherals listed here influence DFSDM behavior. Please refer to the corresponding peripheral training for complete information. This slide presents the key differences between product devices


Silicon quantum devices are becoming more advanced, requiring new techniques for monitoring and controlling them. We have developed methods for monitoring and controlling these devices using gate voltage pulsing and gate-based reflectometry.  Additionally, our techniques can be used to scale up these devices to larger arrays, which could lead to the development of quantum processors. This article was offered by Fabio Anceloni, Jojbo Haslawski, Federico Fedele, and others.


فشرف بل اشتغالي بالعلم ولا تبغي به ما عشت يا بدا بدا وياله من شراف عظيم سويب العرب رحمه الله يسaid فالجاهل والمخطيور the ignorant one and the mistaken one from this Ummah ولو عاملة من الكفري if he does and he comes with a kufr والشرك and he comes with a shirk ما يكون صاحبه مشرك and the person doesn't become a mushرك no disease becomes a kufr فالنو يعضره بالجاهل he's excused for his ignorance والخطائي he's also excused for his mistake حتى يتبين له الحجة until the proof becomes clear to him التي يكفل وتاريك وها the proof in which if a person was to leave that proof has to be what he said بيان الواضحة it has to be crystal clear ما يلتبس على مثله it cannot become mixed with something like it it has to be able for him to distinguish it from everything else وينكر ما هو معلوم بالضرورة من دين الإسلام منما اجمعوا عليك اجمعا كطايا يعرفوا كل من المسلمين من غير النظرين وتهمونين so what does he say بيانا واضحا يلتبس على مثله it has to be clear cut to him and it doesn't mix up with anything else to him so it has to be clear in his mind for him ابن قداما and this context that he's mentioned is ابن قداما رحمة الله in his great book and in his Mughni the 12th volume page 277 he's mentioned this in the context of some of the Salaf who made permissible for themselves something that was Haram they made it and they were doing it out of interpretation okay they misinterpreted a context okay there were a group of companions who thought drinking alcohol is permissible are you with me and they actually went and they drank alcohol are you with me and the reason why they drank it is based on the ayah Allah says in the Quran and this was قدامة ابن مبعول by the way the noble companion he went into house and he started to drink alcohol when he drank the alcohol him and a group they were taking the ayah as an evidence which is that there is no burden a person who comes with belief and has come with piety what they eat and what they drink doesn't matter as long as they come with piety so if they took this verse they went in a room they got the alcohol out and they drank it عمر ربي الله تعالى عنه he had he took them he said to them hey what happened what are you guys doing you guys are not just drinking alcohol you're saying alcohol is permissible but of course قال تعالى الله said عمر ربي الله removed his doubt from them and then once he did he didn't do no takfir on them he did not do takfir on them he removed the doubt that was there with them once he did he lashed them for drinking the alcohol now pay attention here the ayah that they used was what in what context this ayah was referring to a group of companions who took Islam when they took Islam there's a group of companions who what who took Islam and when they took Islam they died before that alcohol was made haram and group of companions these were the early Muslims they came into Islam and they used to drink alcohol and pork was it made haram yet except sure right then after that things started to be made haram so the sahabas when the khamar became haram and the consequences of khamar became anybody who drinks khamar this is going to happen to them and they realize the dangers of khamar now so they asked the prophet they said يا رسول الله where is our brothers who used to drink khamar with us what's the ruling of those brothers who used to drink khamar before the ruling came and this ayah came down that doesn't matter from those Muslims who drank who ate it doesn't matter what they ate or drank as long as they came with iman and fear of Allah does it make sense that was the context of what it came down on are we all together does that make sense now does it make it more clearer so they took that ayah and they applied it on themselves at that particular moment they always removed the doubts from them are you with me so ibn Qudam's statement is in that context he is talking about some of the salaf who did this so he mentioned who تكفير was not placed on them he says فَا يُخَرُ رَجُوا فِي بَمْكَانَ مِتْ لَهُمْ anyone like them is also given the same ruling meaning that تكفير is also stopped from a person who comes with the likes of this doing وكذلك الله that is what كل جاهل and the same is every ignorant person بشيء يمكن أن يجعله but it has to be in something that he is that it is possible for him to be ignorant about لا يحكم بكفره you can't place takfir on him حتى يعروف ذلك until the matter is being made clear to him وتزول عنه الشرحة and the doubt is removed from him ويستحله بعد ذلك and if he makes a halal for himself after that then he is made تكفير is made on him are we together so he mentions three things here he mentions that the thing that he is ignorant of it has to be something that is a person can be ignorant about okay it's something a person can be ignorant about also okay is that the person is informed of what the religion says about سمعت الهو it's haram the third one is وتزول عنه الشرحة and the doubt has to be what removed from them he mentions that شيخ الإسلامي بل تيمي says وها كان الأقوال التي يكفر قائلها كان يقول الرجول لم تبلوه نصوص المجيبة لمعرفة الحق وقد تقول بلغته ولم تثبت عنده أو لم يتمكن من فهمها شيخ سام تيمي says وهذه الأقوال التي يكفر قائلها شيخ سام تيمي says and these statements in which a person can become a Catholic by saying it okay قد يقول الرجول sometimes it can happen that a person لم تبلوه نصوص that takes your evidences haven't reached him المجيبة that necessitates لمعرفة الحق to know the truth these statements are but sometimes a person it may not reach the proof that the evidence is stating okay explaining to him the necessary knowledge that is needed for him to know وقد تقول بلغته or sometimes it may even reach him when I'm تثبت عنده but these evidences are not authentic so he goes and he does it are you there او لم يتمكن من فهمها or he was unable to understand it he reached him but he wasn't able to understand the evidence وقد يقول عرضت له شمهات or sometimes doubts have presented itself to him يعذيره الله تعالى الله will excuse him for that شخص يمسي نلانستاني فمن كان من المؤمنين مشتهد في طلب الحق شخص يمسي anybody who is from the believers who is driving his مشتهد he's driving في طلب الحق and looking for the truth واخضاء and he does a mistake فإن الله سبحانه وتعالى يغفر الله الله will forgive him for it خطاءه his mistake كائنة من كان whoever that person may be سواء و whether it those matters are in في المسائل النظرية أو العمالية it doesn't matter whether they are theoretical issues or whether theological issues or whether they are practical issues so whether they are أقي the related issues or even whether they are فق related issues هاد اللي العالي أصحاب النبي this is the belief the companions and this is their guidance وجماعه رئيمة الإسلام and the majority of the أرلماء of Islam this is what they believe it's powerful ابن القيب says إن قيام الحجدي الشيخ أصحاب تهمية is one is in his كتاب المسائل المار دي ميدية رحمه الله he matches in there in page 66 and if you go to his مجموعة الفتاة you will find it in the 22nd volume in 346 ابن القيب mentions رحمه الله in his كتاب طريقه الهجرتين page 414 he says إن قيام الحجدي أصحاب النبي يختلف بخديلا في الأزمينة والأمكنة والأشخاص it differs from time to time places to places individual to individual فقد تكون فقد تكون قوم الحجة فقد تكون حجة الله على الكفار في زمان دو زمان sometimes the proof of Allah might be established under these believers at a particular time and not a particular time وفي مقعة وناحية دولة أخرى and sometimes the proof might be established from them in a particular land and not in another land for example in London we might say for instance at the كفار in London for example the proof will be established for example but they can feel in the Amazon forest and you there the Amazon forest will say this kafir doesn't know he's doing the proof may not may not have been established on him or might say not كما أنها تقوم على شخص دولة أخرى sometimes it might be established on a person but not on another person they are in the same land the proof is being established on this person but not on this person إما لأدى بعقله وتميزه because this person is either young or he is insane or etc وإما لأدى بفهمه or maybe he couldn't understand كذلك لا يفهم الخطاب like the one who can't understand when he is being addressed yeah there are some people have you realized whenever you tell them to do something they always just don't understand just never understand it turns out to be a lecture when I was basically trying to say it was right هكذا خلقهم الله الله created them like that right so what do you do to those people شرعنا معضول تيقى معضول ولم يحضر ترجمان يترجم له and no one came to explain and translated to them فهذا بمنزيلة الأصم اللذي لا يسمع شيء this person takes the ruling of the deaf one ولا يتمكنوا من الفهم and he was unable to comprehend ووأحد الأربعة الذين يدلون and he is from the four الذين يدلون على الله الحجة يوم القيامة he is from the four who is going to have a proof the day of judgment to argue for the one who called on Islam the proof ولا يتمكنوا من الفهم شخص المرقيم سيزده are you there شيخوا الإسلام بحمد عبدالله رحمه الله يقول الفتاة والمسائل الشيخ محمد عبدالله page 11 وإذا كنا نقفر and we don't do تنفير on what من عبدالصلام the one who worships an idol على قبلة عبدالقادر on the shrine عبدالقادر الصلام اللذي على قبل أحمد البدوي and the one who worships the idol that's on the grave of أحمد البدوي وامثاليه ما أن الناس of these two لأجل جاهليه وعدم من ينبه due to their ignorance and somebody who's going to bring it bring it to their attentions فكيف نكفر how do we do تكفير من لم يشرك بالله إذا لم يهاجر إلينا ولم يكفر ويقاتل سبحانك هذا مخطر العظيم وماذا is important to me here محمد العبدالو هذه إخوة أتمنى إن شاء الله هذه الكلام يجب أن يفهم بحقوق يجب أن يفهم محاضر أن يفهم أصدقائي من أحمد البدوي يجب أن يفهم يجب أن يفهم يجب أن يفهم لأن إذا كنت أصد было سنية إذا كنت سأل عن كتاب والمرد والأراد أف lum أاللم هي فتاة مجبدة كيف يمكننا أن نقوم بذلك؟ لذا أعتقد أنه جداً مهمًا للمساعدة لكتبه في كيف أن نفهم إمام محمد إبن عبد الوهب وإنه يكتبه وإنه يكتبه وإنه يكتبه وإنه يكتبه حسناً لذلك جداً وإنه يكتب Librال ع constellation When some of the conditions we mention That if the person is new to Islam that's another issue If the person lives in the Amazon forest that's another issue All of those are you there? We say that we'll take it into consideration But if a person calls theuth Even though we say he is excused in this dunya he is لكنه يمكن أن يكون هناك خطأة في اللحظة العالمية ويكون هناك خطأة في اللحظة العالمية هل أنت أخي؟ even the one who is in the Amazon Forest to us who are in the Amazon Forest and we deal with him as a kafir he is an excuse that we are talking about here is what? the day of judgment the day of judgment Allah will deal with this issue هل أنت؟ but what is it that the author here mentioned he mentions قيام الحجة here that we are talking about is that the ignorance is removed and they understand it somebody who is going to alert them because some of them are you with me some of them instead of saying some of the copies they say somebody who will allow them to understand look at the طبع of أبا باطين look at it الشخصالح الأطرم and محمد الدويش in the تحقيق of the رسالة they pointed that out so what did we take from the بقول the statements of these are these people of knowledge we take from it is that the proof is established on the person and they also understand it and that the تكفير can't just be oh I read the verse on the pencil now we are going to move on to the last and fourth is the last of the شروط التكفير العين وموانعه وموانعه بيانه شروط التكفير العين وموانعه so we were speaking about the conditions of placing تكفير on a particular individual and the things that can prevent it right what was the first that we spoke about we spoke about بالغ العقلة that the person has reached age of puberty and he has sanity the second that we spoke about is أن يقع منه الكفر ومكفروا على وجه الاختع that he fell into this كفر with his own will meaning willingly he did it number 3 is أن تبلغه الحجة that the proof reaches him التي يقفر بخلافها the proof has reached him okay and the fourth and last one is أن لا يقول متأولن that's what we are going to be speaking about now which is that the person, this individual he can't be a متأولن he can't be an individual who has interpretation so if a person has an interpretation then there is a factor in front of you that prevents you from placing تكفير on them أن لا يقون الشخص الوعيل متأولن and the evidence of the Quran and the Sunnah has shown this the Quran and the Sunnah has shown that تقويل interpretation is an excuse it's an excuse that the Sharia takes into consideration and the way that the كتاب and the Sunnah have shown that is in two ways that it's an excuse one is generally okay the Quran and the Sunnah were general about it okay they stated it generally such as stay with Allah ربنا لا تؤخذنا إن مسينا أو اخفاءنا متأول the person who is doing interpretation he is a person who is coming with a خطأ a mistake so he falls under that and as you know the Hadith of the Quran وضع عن أمتي وضع عن إن الله وضع عن أمتي الخطأ والنسيان ومستكره عليه this Hadith mentions that Allah has excused my umma الخطأ mistake والنسيان and forgetfulness ومستكره عليه and anything which they have been burdened into شيخ الإسلامي بلوتيميا he says المخطئ مغفور له بالكتاب والسنة قال الله تعالى في دعاء ممنين ربنا لا تؤخذنا إن سينا أو اخطانا وثبت في الصحيح أن الله عز وجل قال قد فعلت وفي السنة ربن ماجه وغيره أن النبي صلى الله عليه وسلم قال إن الله تجاوز علي الخطأ والنسيان إملوتيميا says من هجو السنة اللبوية the fourth volume paid 458 إملوتيميا uses the two evidence that I used he says والموت أول the one who has interpretation المخطئ who has come with a shortcoming مغفور له بالكتاب based on the Quran and the sunnah so given ربنا لا تؤخذنا إن لسينا أو اخطانا and the famous and the famous and the second evidence is what إن الله تجاوز عن أمتي الخطأ والنسيان ومستقرح علي which is the sunnah إبن ماجه شهر مان authenticated if it's the sunnah إبن ماجه رحم الله and he also authenticated in his تخرجه مشكاته مصابح the second way that the evidences of the Quran and the sunnah have shown that the person who has interpretation is forgiven is occasions that people came with interpretation in the Prophet's presence or at his time people did things which were wrong but they did it based on interpretation and the Prophet ﷺ forgave them so this is the practical side of it and from that is the famous حديث بخاري narrated by حديث عبدالله العبار that the Prophet ﷺ he said خارد بالوليد and he said that to the people of جديبة بني جديبة فدعاهوا من الإسلام خارد call them to Islam فهم يحسنوا أن يقول they were unable to say اثلامنا the people were unable to say اثلامنا we have taken Islam we become Muslims they were not able to say that so they kept saying صبعنا صبعنا صبعنا صبعنا and when they meant by صبعنا صبعنا is we've left our religion and we've come to another religion but they haven't mentioned what religion they've come into but what they meant was we've left what we're upon and we've come into Islam they were not knowledgeable enough to even say اثلامنا we took Islam and they did think that the Prophet ﷺ what he came with was that statement which they used صبع and that's what they used to hear about the Prophet ﷺ خارد بالوليد because he hasn't heard from them the statement اثلامنا we've taken Islam and he killed them he killed each and every one of them and the ones he could take as a spoils of war he took them as spoils of war he gave every person خارد بالوليد after finished he divided the spoils of war he gave everybody his captives until one day until one حتى إذا كان يوم أمر خارد أن يقتل كل رجل من أسيارة until one day خارد commanding us all to all kill our captives he said everybody kill your captives when he divided amongst the people is that everybody you kill your captives and عبد الله بن عمر he said I said to Khalid والله لا اقتل أسيري والله I'm not going to kill my captives ونا يقتل رجل أصحابي أسيرا and no one from the no one from amongst the people should kill his captives so the matter was brought to the Prophet ﷺ when the matter was brought to the Prophet ﷺ the process when he was told عبد الله بن عمر these people said because they were unable to say and Khalid still killed them when the matter was told to the Prophet and the Prophet had to say the Prophet said اللهم إني أبرأوا إليك من ما صلع خاليدا والله I free myself from what Khalid did so Khalid what he did was to wheel interpretation even the if what Khalid did was if the tail wheel was interpretation is what he used because he understood from the statement سماعنا is not what brings you to Islam are you there so that was his efforts and his hard work and what he came with if Khalid if his tail wheel was not accepted what would the Prophet have done he would have killed Khalid because he killed Muslims deliberately صحيح and that shows that Khalid's tail wheel was what stopped him from being killed and no one killed Khalid or didn't kill Khalid رضي الله و تعالى عنه و لذلك الناس و الشيخ عسام تايني سيث و لي هذا لم يعاقب النبي صلى الله عليه وسلم أكل من أصحابي حتى يتبيل له الخيطة الأميضة من الخيطة الأسودية لأنهم أخطوا في التاويل و لم يعاقب عسامة بلما قتل رجل الذي قال لا إلا الله لأنه ظن جواز و قتله لمعتقد أنه قال اتعودا the same as the Sahabas they were eating and they were drinking in Ramadan in Ramadan they were drinking until what they did was they took a rope they tied it on their shoes and their legs and they were looking at the rope if they can they were taking the rope the white rope until they can tell it because it's dark outside and if the rope is white you would have to tell it when it's wet until it's proper bright so that means they're waiting for too long for them to tell the to tell the rope are you there so they were eating past the time that they should have eaten but they weren't polished for it because they took the ayah as apparent they took the ayah the way they took it are you there يقولوا واشربوا حتى يتبين لكم الخيطة الأبيض ومن الخيطة الأسودية من الفجر ثم أتموا ثم أتموا صيامة إلى الليل they took the ayah like that so they actually took a rope and they were distinguishing it based on that the Prophet didn't say to them you're fasting is wrong you guys are going to get beaten up for what you did because of the interpretation they were excused أسامة المزيد in the same when the man was fighting with أسامة المزيد and he did what he did to أسامة المزيد okay what did أسامة say the man said لا إله إلا الله أسامة المزيد he killed the man when he killed the man what did the Prophet say عليه الصلاة والسلام and أسامة's and his effort took him to a conclusion what conclusion did he reach into that what this man was saying it تعودا he was saying it to run away he knew he got caught he believed that this was not a genuine shahada شخصامة المزيد وكذلك سرية التي قتلت الرجل الذي قال إنه مصم وأخذت ماله ولم يعاقن فيها لأنه كانت متأولة وكذلك خالد هي خالد زي لما قتلت بني جديمة لما قالوا صباقنا لم يعاقن فيه تأولي لففد الكلام المخزمان وكذلك السديخ لم يعاقن فيه خالد عم قتلي ماليك من الويرة لأنه كان متأولة خالد also killed another person as well at the time of Abu Bakr he killed ماليك من الويرة and he killed again it's on تأول so many occasions the Prophet's and people were doing things and the Prophet's was giving them what he was giving them التأول interpretation and he was making التأول or what عذر عذر شرعي الشرعي excuse صلى الله عليه وسلم وعلي and so now we have finished we have finished the mentioning of the things that give you an excuse I give you what I give you an excuse from تكفير being placed on you individually after these conditions that we mentioned if something is كفر you have to look at these four conditions before you specifically place تكفير on a particular person that is what the evidences have shown that is what is مقررر من مدهة إهالي سنة this is what is signified and it's affirmed in the methodology إهالي سنة و الجماعة إن الله سبحانه و تعالى he knows best and we will إشاء الله تعالى we will leave we will leave and stop at this particular point next lesson إشاء الله تعالى we are going to break examples practical examples of the سلاف وهذه أمة أئمة السنة when they did not do تكفير on particular individuals because the condition wasn't there they are going to bring examples practical examples some of the أئمة السلاف أئمة السنة في عدم تكفير بعض المعيينين they were making تكفير of something and they were saying anyone who says this is a kafir which was تكفير مطلق أر ميش تكفير but when it came to particular individuals they won't do تكفير on them they were still praying behind them they were still making دعافنا will be examples إشاء الله تعالى إشاء الله تعالى أئمة محمد رحمه الله he regards خلفاء of his time the leaders of his time how they some of them were saying that the Quran is created and Ahmed believed that anyone who said that the Quran is created they were a kafir to him بعدلك أحمد didn't make تكفير of those leaders we're also going to take موقف الشيخ الإسلام in his position regarding those who opposed him رحمه الله رحمة الواسعة the next one is the position regarding الشيخ الإسلام رحمه الله رحمه الله and those who opposed him those are the three إشاء الله تعالى we go to mention بإذن الله الكريب in our upcoming class we also be looking at إشاء الله تعالى who has the rights and who is the right for individual to give the label of تكفير who is allowed to give it who is the person who is allowed to look into something whether it's تكفير and I can place تكفير on you or not who has the rights to do that okay we're going to be speaking about that إشاء الله تعالى and that's going to be our final conclusion بإذن الله الكريب we have finished our introduction بإذن الله الكريب next lesson next lesson إشاء الله تعالى we would have finished our what we would have finished our introduction and the week after we will start إن شاء الله تعالى لكتاب نواقظ الإسلام so not next week but the week after we will be starting نواقظ الإسلام but next week we will be talking about those two points I aim to set up practical examples of them not placing تكفير on a particular individual and the last one we're going to be speaking about is who has the rights to look into these issues and speak about these issues and label people with تكفير anything which I have said that was wrong in this class it's from me الشيطان الله is messenger I free from it سبحانك الله بحمدك أشد أن لا إله إلا الله أستغفرك


these are about resolutions. What is the how does it scan earlier scanning was in spectral it used to be split up here. This it gets split up the beam that visible spectrum is split up into various bands of blue, green, red and all that and it used to scan across track scanning. Of course, it has its problems we will not go into the this is what is called spatial resolution. How does it how do you say the instant instantaneous field of view is this angle right and in terms of the you know size of the pixel how do you get the size can you tell me this d I want h is the flying height and beta is given beta is the angle h into beta that is how it is so spatial resolution depends upon the height at which from which it is seeing plus the angle beta that is if these two are known then you can find the spatial resolution it has some problems with the you know what is the resolution in case of a photography resolution spatial resolution is only in terms of in for the digital images because pixel wise it comes but in case of photography there is no pixels it is all in one go we get so it depends upon in one mm how many black and white lines you can you can see the same thing is getting repeated the center so under microscope you see them and in one mm how many black and whites you can discriminate that gives the resolution of the photography and the scale of the photography is known that gives divided by this will give you approximately what is almost equal to parallel to the pixel size or the resolution but it's not it is a different type there are some problems because of the scanning you know the every pixel size may not remain same so and it creates its own problems I don't and that is how what is supposed to be on the left side it looks like this because of these problems anyway that is all details how it can be corrected and these are the things that it can have even the plane that can have so to avoid these you know distortions finally now it is a CCD technology if the IRS IRS have been adopting Landsat and Landsat had that but the later satellites all that is every CCD detector detects one pixel the radiance from one pixel or reflected energy from one pixel so each what is the problem here it is good at least it need not travel right it need not move but problem is you should be able to calibrate every detector and thousands of detectors seven hundred seven thousand like they're depending upon the spatial resolution and the total ground width that you want to cover in one you know travel so that depends on that so you can see all though all of them have to be calibrated and some of them may be speed whereas in the scanning no only thing is when it gives the problem so this present technology is mainly on CCDs charged coupled device okay some of these resolutions that I have given is about for the Landsat for spectral resolution spatial resolution and of course radiometric temporal that you can calculate but what probably I have not given is our Indian IRS one-way one C1D now it is resources set and Cartosat resources that gives up to five meters and Cartosat gives up to that is the latest that India has achieved and of course there are view and all that which can give you even in terms of you can see four meters and one meter and that comes to even point six five with one of the satellites that is the order that we have gone into what is a satellite it's something that you know lands are these are supposed to be the satellites from the very first beginning that have been what are their orbits their orbit something look like this why are they so earth is moving and it has slight inclination also it's not that it is coming down polar satellite orbits okay at synchronous orbits or communication satellites because they are most synchronous with the rotation of the earth this polar orbiting satellites it doesn't come like this it comes with a slight inclination and then coupled with that earth movement when you trace their paths they become little of this type so so these are the various bands that you know TM Landsat for TM has that sensor has these many bands each has been useful for a particular thing can we discriminate snow and cloud both of them how do they look like in terms of energy when it comes both will be white ish or whitish so how do we discriminate them whether it is a snow or shadow shadow may be difficult reflect but how both look almost white so how do we so this mid infrared of 1.55 to 1.75 this can differentiate snow from clouds okay snow has low reflectance clouds have high reflect this is the only band which can discriminate between the clouds and snow no other way that you can find out that is how some of the bands are good for something vegetation infrared like that you can decide depending upon the spectral reflectance cuts that we have seen if you have those curves studied carefully you should be able to say that so how do we process these data digital in in terms of visual or with seroscopes we have seen say can we process of course this has been processed digitally only there is no manually it is almost impossible so there are various facets of digital image processing rectification and resolution restoration image enhancement image classification data merging and GS integration bio-physical modeling it is not an exhaustive list or what it compartments some of them are listed and sometimes some of them get merged with some other thing or maybe further classified it all depends upon what is image rectification and restoration one is geometry correction radiometric correction and nice removal how do you determine the geometry correction what you have scanned how does it relate with respect to the ground otherwise how do you interpret how do you use the maps that is geometric correction and the radiometric correction is atmosphere may not be same you know in winter and summer does the inclination of the sun does the you know distance to the sun will it remain same in all seasons yes or no so then that have to be taken into account otherwise the how do you normalize this radiation what gives as more energy that reflectance coming but maybe because of other factors also so unless that we take care of corrections that becomes radiometric correction and then finally noise removal so many the other pixels may be contributing atmospheric reflectance may be contributing so it is all that if you want to if you can remove then only you can give a better interpretation something like this you know it may have the real pixel ground pixel may be given by the three four pixels because exactly where it may not start so you should be able to do this geometric correction or based on nearest neighborhood or you know higher-order equation that whatever you feel a more involvement of mathematical things then it is up to you so you should be able to get to the thing and it is something like this the satellite is at one place the sun's altitude keeps changing and even the distance this has to be corrected before we proceed for because finally the reflectance variation you will see and interpret yes or no so unless those things are corrected it would be it would not be correct to say that so what is enhancement is a contrast manipulation gray level thresholding level slicing contrast stretching spatial feature manipulation spatial filtering edge enhancement multi image manipulation band ratio in principle components vegetation indexes plenty you can what exactly does image enhancement is image enhancement necessary for image classification I am not showing you to you know frighten you know it's only some of these terms I thought okay so let us not discuss every one of them but then let us know is image enhancement needed the previous image rectification and restoration is a must step before we go for classification I finally what we want is image classification yes or no so that how do we get before that rest rectification because I should know what area I am referring to and then so there is a major enhancement is not a necessary step what is required is enhancement is only for visual application not for digital application if you want to see if there is no contrast in the image then it would be difficult to discriminate between different classes so we do enhancement for visual application not for digital so it can be gray level thresholding a level slicing and contrast stretching and of course many manipulations of spatial filtering edge enhancement multi-image manipulation ratio in principle components vegetation this is all these things come center what exactly means by this suppose if the gray level values are only within this range working gray level values are only within this range it may be difficult to discriminate between two classes because they are very close there is no much of a difference in terms of its radiance values yes or no so if I can but I have the wide band spectrum I can divide into you know 0 to 255 whereas this has occupied only hardly from how much 100 to 159 so if I can redistribute them so that this contrast gets better so that I can discriminate the classes that is what so that is various linear stretch histogram stretch non-linear stretch there are many methods let us not get into the details but this is what essentially done and is only for visual when you want to do classification digital classification you use the original data not the not the enhanced data and sense they start not to be it is only for for us to say okay whether can I discriminate between these two classes so that is what is mainly the and of course finally the class and the previous ones if you want to have an idea about this is level slicing you know just I want water and land that's it you slice into two that's it that is how you can improve and in land then again you come back to the discrimination contrast stretching stretch the fear the spatial filtering some filtering methods help because this is not the lecture on digital processing so I am only just touching under this because this only one lecture I should cover the fundamentals as well as the digital processing and the sometimes the filtering and edging enhancement will improve multi-image manipulation band ratioing suppose there is vegetation on the side which it is looking towards the Sun as well as the other side of a hill will it emit the same type of radiance will it emit the same radiance at the detector one is on this hill slope which is facing the Sun the other one is on the leave other side of the hill which is not facing the Sun and the same type of species or vegetation is available which one there won't be so and then but can we classify as a different feature are we right we are not so this band ratioing helps if you ratio between two bands visible and infrared the ratios ratioed values will remain same irrespective of these effect of these topography can be removed and that is how band ratioing helps okay and of course principal components is data compression most of the thing that they are correlated you know the correlation is very high then you can reduce the data content by principal components and then vegetation is a near infrared to red you know red to near infrared and all that these vegetation gets enhanced in this ratioing of vegetation index is also a ratio so some particular purposes these are being used okay finally our interest is in classification because either visual interpretation or digital classification so if we have a we can have supervised unsupervised and in hybrid classification and finally how do we assess the accuracy of course there even other methods like artificial neural networks nowadays and these methods are available but basically the standard methods had been supervised unsupervised for quite a long time artificial neural networks have come in now so what is it supervised classification supervised classification means unless I know this area power area there is water body nearby there is vegetation nearby and of course there are other features if you have some pixels which you know them as water vegetation and other features that will be given as an input those features with similar radiance value should be identified as a class of water if you have 100% ground truth no need for classification yes or no can you have 100% ground truth then there is no need for classification so you have but is can we reduce yes with increasing you know type of spectral spatial and all that you can reduce but you can't eliminate the ground okay so you take them that is what is supervised classification so it's radiance values mean okay variance covariance matrix all that you have to extract and then process the whole data and look for these things so that that areas are marked as that particular class that is what is supervised it can be minimum distance to mean parallel pipe does Gaussian we will see unsupervised classification is k means ISO data unsupervised means I don't have any idea about this type this area but still I would like to classify okay so that is what is unsupervised how do you do you you classify into some clusters because of the radiance similarities and then later you have to identify what the cluster means it is post classification visit to the site is required whereas these collection in supervised is a pre classification exercise it depends upon if you have that that is supervised if you don't have you say that these are different clusters that I could identify and then go back to the site and see what that cluster represents and then give the title for that okay so that is what is the thing and hybrid classification the combination of these two and the classification accuracy can be assessed always so these are the various types of you know particular feature and in every band what are those values you know reflectance values that we get all digital numbers now this and that reflectance are converted to digital numbers so these are the various layers that we have same pixel can have different values in various bands and finally how do you classify the various types of classification is suppose say you have these you know you have plotted back only one band data band 4 and their reflectance values in terms of digital numbers reflectance values can be converted to digital numbers and vice versa okay and if you see these are all urban and you know that different thing forest water like that a pixel which is at place one in which class does it go for these different methods are used whether it is you know supervised that parallel pipe minimum distance to mean or the statistically maximum likelihood classification all these methods so how does it how do you what do you think that pixel one should go pixel at place one should go to which class class C is it so nearest name minimum distance to mean it should go to class C yes or no but if you take the distribution into account where it is going this is parallel pipe because you have seen the distribution if it take into this type of distribution then where it is going it may keep changing and finally when we go to maximum likelihood where does it go distribution is according to the distribution we draw that yes that is maximum likelihood so you can see there are various methods for this supervised classification okay these are some of the methods and unsupervised you don't know these are all how they are represented you know how each class sometimes it may be a combined class this if you draw these things it gives you discrimination between class to class that is and the spectral radiance that plots also give you which classes are getting overlapped which classes are independently can be seen okay and how do you say this you know what is the classification accuracy finally that you are giving see you have to know some supervised only that can be done otherwise unsupervised you can't do unless again you collect something so what we do you take these are all the ground truth these 233 pixels at the column one w these are ground truth and what have been classified as rows you please see now an area with these pixels as ground truth have been classified and the classification that pixels under that class have been given in the last row can you see this these are the ground truth pixels at the bottom these are the classified pixels now if you see the producer's accuracy is 226 by 233 is 97% and the user's accuracy 226 by 239 is user's accuracy and overall accuracy based on the diagonal terms because the same the pixel should belong to that particular class that is given by diagonal so that is called overall accuracy so what is producer's accuracy and what is user's accuracy producer's accuracy is how many pixels that I have as a ground truth the fellow who uses map will never know will ever know so to satisfy myself what I have taken and how it is giving that is given by producer's accuracy getting I know so I can do producer's accuracy as a producer of the map I should know how good is my map okay whereas I am as a user you as a user the map that is produced by me if you check you check the ground truth as well as that what is produced only 239 pixels are classified but actually water is only 226 so your accuracy in terms of what you can expect from that map is called user's accuracy only the fellow who produces can have the producer's accuracy to satisfy himself how good is the map that he has produced but the users are the judges finally to say in terms of their usage what is the accuracy that is overall accuracy is in terms of this these are called you know the matrix error matrix are also called termed as confusion matrix various applications of remote sensing can be land use land cover geological and soil mapping agricultural applications okay range land forestry urban wetland wildlife archaeological environmental oil exploration mineral expert many it is not the end of the list not an exhaustive list there can be many more okay everything under the sun is supposed to be possible but everything has its limitation if it is land use you know usgs classification of land use residential urban in that sub you know level 2 classification various that you can see and even level 3 4 you can have your own this is the type depends upon the spatial resolution that you have that you can classify right and let us say back as as we are water resource engineers I mean that is the purpose of this course so let me confine myself instead of other applications that what we are going to talk tomorrow so let us have how remote sensing can be useful can it give the type of drainage yes or no and the type of drainage should be able to say what type of you know the area that I have whether it's dendritic or the parallel structurally controlled drainage yes or no possible so based on that I know whether the runoff is more or the infiltration is more yes or no more the drainage more than enough less infiltration less the drainage vice-versa yes or no so I should know about the terrain then the you know sparse drainage and the drainage being more intense and the type of the erosion you can say different type of the soils that you can see depending upon whether it is rectangular cut or a v cut or something so less cutting means it is of clay silt sand like that it depends on the type of the and finally what we are interested in the water resource environmental management in terms of what we want in water resources one is a geographic distribution yes or no how are the water geographically distributed then the quantity yes quality groundwater locations if possible finally any applications additional water resource applications like what flood forecasting disaster management right there can be many other applications all these are meant for what can we do with that geographic distribution definitely we can do yes or no because you can identify in black and white it looks little blackish the water in infrared it becomes absolutely black because there is no everything gets absorbed in infrared so that is how when you talk about improving what is it noise removal you can say the in infrared if it has some value radiance value that can be because of the noise the simplest algorithm for water noise removal is that value to be deducted and deduct that much in everything so more or less that is the simplest algorithm for noise removal so quantity quantity is a problem if you have yes the spread of the reservoir based on area elevation curves while surveying for the reservoir yes we remember now area elevation volume yes or no so once you know the spread provided no silitation takes place otherwise you have to conduct what sounding so that the death well there still remains there are not at that point so that you can update these area elevation volume curves yes or no so based on that you should be able to say about quantity in terms of the reservoir storage and all that okay and then about quality quality again it can be whether it is inorganic turbidity whether it is biological turbidity in terms of algal concentration or it could be oil slicks yes or no and of course there can be others like the odc body and all that is it possible to detect everything yes turbidity can be detected in that neflon that units turbidity units because more the turbidity what is the reflectance finally only reflectance more the turbidity less reflectance it is either that or this but you see more the turbidity more reflectance you can see in band 4 even in these satellite images that is how which is near the coast will have more reflectance if you go deep that becomes black so that is turbidity what about biological turbidity more the alga algae of course beyond certain point it may get saturated because the detector itself cannot detect but it has to increase more the algae algae more the because the reflectance in particularly infrared okay and about what is the third one we said oil slicks how does it more the oil slick thickness what more reflectance yes more reflectance so you should be able to estimate dial slick even thickness for that thread we have and of course is the odc body can be detected yes ultimately that is what environmental engineer wants our scientist wants yes or no so whether it can be detected we want to see what it cannot be directly but instead you know indirectly suppose you can spot the fish which are surviving so it is an indirect indication that it can there's bio physical modeling and all that so you can talk say yes it can but otherwise there it as long as the signal is not affected in terms of absorption transmission and reflectance nothing so if reflectance is more or less you can detect but otherwise you can and the be odc body values unless they turn into turbidity cannot be detected because it is dissolved oxygen there could be slight but that is not so that is how we can talk about quality okay we have talked about distribution quantity quality and the ground water location can it be detected can can it go below the ground micro also it is only not much few mm vegetation yes indirectly particular type of vegetation is there and particular type of drainage structures based on that indirectly we can talk about ground water location and additional the flood particularly with the microwave that is being coming it it it penetrates through all weather satellites so you should be able to even talk about the cloud indexing and then taking what can be the potential rainfall that's possible that is what they you know do but that is all it's everything and of course post flood you can see the extent of damage that very easily and the disaster management you know management techniques of how to give the relief for the people even before you know you can plan and the post flood or anything so there are many additional applications that you can talk about and if we say that you can see how these clay soil and silty soil with respect to the intensity from clear water how they are differing that is how the turbidity can be detected okay and the algal concentration with respect to the you know clear water you can see how these reflectance curves keep changing with respect to that and you can see the plumes are thermal that is another important things you see what happens most of these you know things are discharged in the night because others cannot see but you can always have remote sensing and can see thermal particularly these reactors see you can see what is the temperature you can see the clear difference between the black and white yes or no so that you should be able to get to the temperature difference aquatic life is being detected finally my friends I think I am just you know we started a little late so but still I thought you know other person should not wait picture is worth thousand words yes or no because pictures can safely you know convey information about position size and relationship between the objects the basic advantage of these images is what one is vantage point it is from a height yes or no then it is a permanent recording stop action that is what you can see in pity usha though she must have retired from competitive athletics but we can see her picture of competing in the international you know fora even today because stop action yes so that possibility is there permanent recording and of course broad end spectral sensitivity what we see is only visible but it can go beyond yes and then of course increase spatial resolution and all that so remote sensing will going to with respect to in addition to the GPS and the more these things it is going to play a role but we should know its limitations also it is not that everything is rosy there are limitations so we should be able to utilize and to the best of its capabilities and that is what so we know bhabhavaya said that spirituality plus science is Sarvodai science minus spirituality is Sarvanash and spirituality minus science is suicide so can we club these two things of science and the sustainable management that is what probably would be an ultimate you are the best judge to use to what extent to damage to what extent the natural ones probably little more about it we will talk about tomorrow