Hey, I'm very excited to be here and at my first DMF camp. So thanks to everyone who's making this wonderful event happen. I often give technical talks at events like this and this one is not technical. This one is just about my experience is starting an open source hardware company, Great Scott Gadgets. We make a number of things like the ubertooth, which is a Bluetooth test tool and hack RF, which is a software defined radio platform and a variety of other things that we're working on. And I kind of didn't really think about the fact that I would be starting an open source hardware company until it sort of happened. And I wanted to kind of tell the story and maybe it would be helpful to people who are thinking about making a similar leap, perhaps. But I don't sometimes folks ask me for advice about starting a business or something. And I say, well, you know, I don't know how much advice I have for you, but I can at least tell you how it went for me. And so that's what I'm doing. So my story or the year that I'm talking about starts in October of 2010 with Tourcon 12. And this is an information security conference in San Diego. And I had kind of a busy year. It was the second time I taught my software defined radio class there. And I gave a couple of talks as well. One of them was uber tooth zero a preview. And I had designed this circuit board that was like the first it was the first PCB I ever designed. And it was called uber tooth zero. It was deliberately named zero and not one because I intended I intended to replace it. It was just kind of an initial prototype that could be made to demonstrate a Bluetooth sniffing function. And in particular kind of the killer app of uber tooth was that it can detect and identify non-discoverable Bluetooth devices. And this was a capability that had been missing before. It had not been possible to detect non-discoverable Bluetooth devices prior to this without spending like $10,000 plus on test equipment. So we were pretty, I was pretty excited about it. And I wanted to show people what I was working on. And it was just a short work in progress kind of talk. But when I was there and showing this to people, a lot of my friends in the information security community started asking me, when can I buy it in shops? And I was like, I don't I don't know. Like the originally when I started the uber tooth project, I was trying to make something that people could make for themselves. I wanted it to be open source hardware and or pieced together from off the shelf hardware. And it turned out that I ended up designing the thing kind of from scratch instead of piecing it together from other things. And so it turned out to be something that maybe would make sense to manufacture for people. And so I started thinking about that and thinking about what it would take to manufacture this thing for people. And this was all kind of a side project because I had a job at the Boulder Labs in Colorado. Doing wireless security research.  And I wasn't really looking to start a business. I just was looking to get this tool into the hands of people who could do something useful with it. So but after work on, I started thinking seriously about starting a business and what that what would that would mean and how I could manage to do that on the side and and get this tool out to more people. Initially, that meant I would start kind of redesigning or refining the uber tooth zero design and working toward uber tooth one. And I found this talk by Mitch Altman online and Mitch, I believe is here somewhere. So if you're listening, thank you, Mitch, because this talk that that he had given at some event, not too long before this, had a video posted online and I watched it and I thought, wow, that's pretty cool. Maybe I could maybe I could do this and kind of what he did and following his footsteps, starting a hardware company, building something that that I really enjoyed doing. And it's this talk in particular is full of more practical advice, I think, and probably more so than this talk today. So I would recommend it to you if you're interested in pursuing a similar path. He's he had a couple of particular insights that I thought were very interesting. One was don't do business with people you don't like, which has been a guiding principle for me ever since. And it's it's worked out pretty well. And he really got me thinking about how kind of the economics of of running a business and how I would do pricing, for example. So the pricing is something that was super important for me to be thinking about at that particular time, because I was figuring out what the what would be entailed in the product itself. And what it would cost to build it and how I would actually sell it. And one of the things that I I considered was a reseller model. And in particular, I considered at least kind of three three different distribution models. One being selling direct like have a website and sell direct to people and ship things individually to so retail direct retail sales. Another would be a reseller model like a two tier reseller model where I would sell to resellers and then they would do the retail sales. And then the third would be a three tier distribution model where I would sell to one or more distributors and then they would distribute things to resellers and they would sell them to other people. And I had some background working for companies in a three tier kind of channel before so that sort of made sense to me. But what didn't make sense was that this product was such a niche product that I didn't really think that a multi tier distribution model really made any sense. There were very few retailers in the world who would likely be interested in carrying this product. So since it will be a fairly small number of resellers, I thought it made the most sense to to do the two tier two tier model where I would sell directly to resellers and then they would sell to the end users and do the retail sales. And that's been my model ever since. And one of the important reasons that I did that instead of trying to sell direct which is more possible these days than it used to be, one of the important considerations was that I was trying to do this on the side. I had a day job and I really wanted to minimize the amount of effort I had to do in order to make this a reality. My goal was just to put hardware in people's hands, not necessarily to, you know, make a growing company, even though that later happened. And so I had a goal that I wanted to make this company a solo company. I didn't want to have to hire help. I didn't want to have to hire employees and so forth. I wanted it to be solo for as long as possible. So I looked for opportunities to kind of outsource different things. So for example, manufacturing, I didn't do my own manufacturing. I outsourced that to a contract manufacturer and then retail sales. I kind of outsourced that to resellers and so forth. And around that time I was kind of getting excited about, well, hey, if I if I now that I know how to design circuit boards, it might be fun to design some other things too. And I had this thing called a throwing star land tap that I had made like 10 years previous that was made by splicing together Ethernet cables. And it was super useful. I use it all the time personally and I, you know, I like doing system administration and network administration and security stuff. And I but one one kind of frustrating thing about it is that whenever I would use it, I would have to use Ethernet couplers like RJ45 couplers. And so it ends up being a lot more unwieldy than it looks because of the couplers. And I thought, hey, now that I know how to design circuit boards, I could change this design and make it make a circuit board and put install female connectors instead of having male plugs on that thing. And so I made the throwing star land tap. And this was a kit that I designed. But at first I just started printing circuit boards and started handing them out as business cards. And I still hand these out as business cards. And I have some here, if you know, if you see me around the camp, hit me up for one. But I thought, well, if I'm going to, if I'm going to have a company that sells a product, maybe I'll have two products. And so I was looking into maybe manufacturing the throwing star land tap as a kit, which I did end up doing later. And that's, you know, a pretty easy manufacturing job since it's just making the PCBs and then grabbing a few components and sticking in a bag. So Schmuckan was in the following January and it was at the end of January. And this was kind of a good timing for me because it was around, it was about the amount of time I needed to finish ubertooth one, which was the refined version of ubertooth zero. And I gave this talk project ubertooth building a better Bluetooth adapter. And it was a, it was a talk that was very much about the project of building ubertooth and how I came to build ubertooth and the challenges that I had, like learning electronics so that I could build ubertooth. And all about the, all about the ubertooth project, primarily from a technical standpoint. And so this talk today is actually kind of a sequel to that talk. And that was about the technical project that then led me to start Grayscott Gadgets. And so this talk is about how Grayscott Gadgets came to be. And one of the things that I talked about in that talk is how I started Grayscott Gadgets as a fake company, because I was just trying to social engineer like part manufacturers. I just wanted to try to get like free samples and data sheets and stuff. And like, so I, so I just sort of invented this company. The first name I thought of was Grayscott Gadgets. And I registered a domain name and put up a website and started sending emails from that domain and, and started, you know, trying to hit up manufacturers for documentation and stuff. And it totally did not work at all. But, but I, I started that. And then when people started asking me later about like what I sell them uberteeth, I said, well, you know, I sort of have this company. And so as an experiment, I decided to take this design that I made ubertooth one, which really was this pretty much the same thing as ubertooth zero just refined. And, and I decided to, to try to go into business with it. And this is actually a slide. These are slides from that talk. And at the time, this slide was about, about how I knew nothing about electronics and how I had to just start from nothing and learn electronics so that I could do the ubertooth project. But it's also highly relevant to running a business, because I really didn't know a whole lot about running a business either. And I made a very deliberate choice that if I were going to bother going into business to, to produce this thing that my business would be dedicated to open source hardware. That everything that I had ever done in my life that or anything I'd ever done in my career that I was proud of was something that I did with the help of open source software. And so for, to me, open source is just the right thing to do. And, and, but that was for me a very deliberate choice that that was one particular thing that I would not compromise on every other aspect of running a business.  And I think it was important to kind of have that mental clarity that that delineation between here's what I'm willing to unwilling to compromise on. I am willing to compromise and learn on everything else. I don't want to have preconceived notions about how this is going to go. And I think that was kind of helpful. Well, I started using this thing called Kickstarter, and it was kind of newish at the time I had only heard about it during this period of time when people were asking me if they could buy Ubertooth. And so I put Ubertooth on Kickstarter and launched it at the time of Schmucon. And it, the funding goal was that green line across the screen there. And so, like, I announced that it was, I launched it like on Saturday morning at Schmucon and then Monday morning it just took off. And I think by Tuesday evening it was funded or something. And, and I thought it was kind of interesting how there it looks like if you look at the plot of the of the pledges that came in for the Kickstarter campaign, that it was sort of exponential growth looking at first until about the time that it hit the pledge goal and then it was very linear after that. And that's a pretty common, pretty common looking curve. I've seen other, other crowdfunded projects have kind of similar results. They don't always look like this, but it's a fairly common looking sort of thing for successfully funded crowdfunded projects. But, and it kind of made me think a couple of things. One was, you know, if I, if I had set the goal higher, would it have been had a longer period of exponential growth? Like did I miss out on things? But I don't think that that was really the right conclusion to draw from this. I've, I've later learned that, you know, setting a pledge goal is really a tricky thing. And setting it high is not necessarily a good idea. But I did make a mistake here. I set the goal at $16,000. And it turned out that I really needed about twice that. And so as it turned out, I did get more than twice that. So I was totally fine. But what if I had been funded at exactly $16,000? What if I had just barely met my pledge goal? I might have had real problems actually bringing this product to market. So I made a mistake here, but I got lucky anyway, that I had enough funding to get past what Nate from Sparkfund is called the pit of despair, which is that kind of middle ground where you, you have enough interest in your product to make it seem like you should be going into mass production, but you actually don't have enough funding to achieve mass production. So I got over that threshold, despite the fact that I set my goal too low, I should have said it about double what I did just to have this, the assurance that I wouldn't fall into the pit of despair. One of the things that I did for my Kickstarter backers was I said, hey, if you, if you fund me at the highest pledge level, then I'll get give you a special edition of Ubertooth and that will come with some extra things like an enclosure and some antennas and stuff. And but I hadn't really figured out how I was going to make the special edition units, like would I make them separately, or maybe they maybe they would just come out of the regular batch and then I would just add stuff to those packages. But I thought it would be nice if I actually had them, the PCBs look different. And so I thought about maybe making them myself on a hot plate, but I had to make 50 of them and that's a lot of work. But meanwhile, some some folks from a company in Australia contacted me contacted me and they were really interested in in having kind of early access to Ubertooth. And they wanted, I can't remember, 10 or 20, something like that. And and they were, you know, willing to pay extra to get them sooner, very soon. And I thought, well, you know, depending on how much they're willing to pay, maybe this is an opportunity. Maybe I could kind of get them to pay for the special edition production. And I'll make a few for the Australians and I'll make the rest for the for the special edition people. And some or all of that special, small production costs would be paid for by the Australians. And that seemed to kind of work out. And we made and I hired a different manufacturer, not the one that I've been. So the manufacturer I had been talking to about manufacturing Ubertooth and that did manufacture Ubertooth was one that, you know, I'd gotten referral to. And I was starting relationship with and but they but it was brand new. I was, you know, I was a first time customer. So they didn't want to add on this extra little, you know, 50 to 100 unit production. They want to do like a thousand unit production or more. And so I hired some like random PCB assembler in China to do the white ones, which was this, which were the special editions. And I had I had 100 of them made. And they it was it was interesting because the the the CC 40 CC 2400 this sort of came up during the special edition. The CC 2400 is a chip that is on the Ubertooth. And it's like the essential chip that accomplishes the Ubertooth function. And it was it was a part that I a couple of things came up during during the special edition production that I had not anticipated about having to do with this part. The first thing was they that my my contract manufacturer for the special edition told me, hey, we can't get this part in China because it's because of export restrictions. And I freaked out.  And and I freaked out twice. And so it turned out that one or more of the distributors had incorrectly identified this part in their catalog as being export restricted from the US. It has other parts in it's in a family of parts where other parts are export restricted and this one shouldn't be. And so I had to like I had to like sign paperwork saying that I was taking responsibility for this decision to ship it overseas and so forth. Which was a little nerve wracking, but it kind of made sense once once I figured out what was going on. And it really wasn't end of life. It had just been recently marked not recommended for new designs, which means they're still manufacturing it. They just are recommending that you that you go to the manufacturer Texas Instruments is recommending that you look at other parts for brand new designs. And well, it was kind of a new design at the time. But but when I had designed this into my product a few months earlier, it was not not recommended for new designs. So I was kind of just at the edge of the thing, but I had no idea like how long it would be available. Like maybe there would never be a second production of Ubertooth one. I hadn't I didn't know as it turns out, I'm still buying CC 2400s in 2016. So they're they're still out there, but and they're still being manufactured. But I was pretty scared about this at the time. It seemed like a huge risk for my venture. And the and then also, you know, I made these I made these special edition boards. I had them made for me then after I managed to get the CC 2400s to China. And they came back to me and I think about 30 of the 100 worked. So so I had to sit down with a soldering iron and start fixing them. And so I had to make like the 50 for my Kickstarter backers and then the 10 or 20 for the Australians. And and then there were a bunch more that never got working and are like still sitting in a drawer. So it was quite a task. I mean, the amount of effort I had to put into reworking those was probably, I don't know, 30 or 40% of the amount of effort. I would have had to do if I just made them from scratch myself, which maybe would have been a better choice at the time. So I kind of learned my lesson about just picking a random contract manufacturer online for small projects. They did, you know, pretty poor job of assembly and and did zero testing, which at the time when I first hired them, I was just trying to get something done fast. And I didn't really think about testing, even though I was thinking about testing for my main production. So I started around that time. So after the after the Kickstarter pledge period was over, but before I shipped during that time where I was getting manufacturing going and such, I was talking starting to talk to people about maybe reselling ubertooth one after the Kickstarter, because it seemed that there was enough interest in it that it might be worth keeping this product going and doing more than just a single production. And the first reseller that that contacted me was hack five. And so Darren from hack five, if you may be familiar with the video series online, they're really into education in the information security community, like helping helping new people get into Infosec and hacking. And so they were in the process of starting an online store. And he said, hey, we're going to be starting a store. And I think ubertooth would be good to have in the store. And I said, yeah, that that's a good idea. Let's let's try to make that happen. And I thought, well, if I'm going to make that happen with hack five, maybe I should have some other resellers too. And so the first ones that I thought of the first reseller I thought of to approach with spark fun, which is a which is kind of a different target market hack five targets folks in the Infosec community and spark fun targets folks in the electronics hobby community. And spark fun also happens to be in my home state of Colorado. So, you know, I'm local to them and I met a couple of people there at the time and I actually had taken a class there on SMT soldering like solder paste stenciling a few months prior. And so I contacted the director of engineering at spark fun and said, hey, I'm coming out with this thing. Do you have any interest in carrying it? And they they kind of took a flyer on it. It doesn't it's kind of an unusual product for them because it's a bit expensive compared to other wireless development platforms of comparable size and complexity that they carry. But it sells well for them. And I think that has to do with with the special function that it is capable of monitoring Bluetooth devices. So so that worked out. And those two were my first resellers that I that I kind of got signed up and took orders from to start filling immediately after after the Kickstarter units were sold. So, meanwhile, I was pretty excited about this whole Kickstarter thing being successful. And I was just incredibly grateful to my backers who had pledged to support this project. And one thing that I decided to do just just as an extra thank you was, hey, I was I was putting this throwing star land tab kit together. So why don't I just give a free one to everybody who gets an Uber tooth because they're pretty low cost to manufacture. So I could just kind of roll that into the into the package, no problem. So I actually had these things produced and had those available to sell to my resellers. Even though it's a very low cost thing, it was nice to have, you know, two products in my catalog instead of one. And and then I actually shipped these things these packages of to my backers in May of 2011. So at the time, I thought like my pledge period for crowdfunding was basically the whole month of February or kind of the end of January to the end of February. And then it took me until I think late May when I was able to ship. And I thought that I was way behind like this was like I really wanted to have to have shipped to them sooner. But as it turns out, you know, like hardware project crowdfunded hardware projects have a track record that's actually a whole lot worse than that in terms of delivering in a timely fashion. So going from the end of February to the end of May was really not that bad at all, especially considering that it was the first time I'd ever done volume manufacturing of anything. It was pretty, pretty successful overall. And I think that a big part of why it was successful was because the version that I manufactured was identical to the version that I showed at Shmucon. I made no changes. It was a bear, a bear board. And it was functional. And the design, you know, I had already gone through a couple of design revisions significantly from ubertooth zero to ubertooth one was a major revision. And when I got it working for Shmucon, I was done. I was like, okay, this is it. This is what I'm going to ship. This is what I put on Kickstarter. And I didn't have to do any extra design or changes to design during the manufacturing process, which I think I attribute maybe the speed of production and delivery primarily to that. So the way that I kind of modeled how I would be bootstrapping this business is that I got like $50,000 from Kickstarter.  And then half of those had to go to my Kickstarter backers. And then the other half were available to resellers. And so all the money from Kickstarter pretty much went into making inventory. And then half of that inventory I was able to sell to resellers. And then the money I got from those was enough to fund the second production of a thousand ubertooth ones. And this kind of worked. This basically was how I bootstrapped the business. And it meant, number one, it meant that I did not have to seek any kind of outside investment at all. And that's super important. I was the sole owner of Grayscott Gadgets and I remain the sole owner of Grayscott Gadgets. And that's very important to me because I can run the business the way I want to, like having open source be such a high priority. But this process of bootstrapping, it worked pretty well. But the reality of cash flow is a lot trickier than it kind of looks on paper like this. This is sort of a simplified view. But really another significant thing is the pricing that I put on Kickstarter was close to the eventual retail price. I estimated what the retail price would be through resellers. And then I use that as my retail price or my Kickstarter price. And that really was important because I didn't just collect enough money from Kickstarter to build the 500 ubertooth that I needed for my Kickstarter backers. I got twice that. And so that allowed me to bootstrap my business. It also was a fair price because actually it was slightly less than what people later were paying for the same product through resellers. And it kind of set an expectation of what the price of this product was. And I think that's important too. So people often ask me, especially in that first couple of years after this happened, people would ask me for Kickstarter advice a lot. People who were trying to launch their own Kickstarter and especially hardware projects because there weren't very many. Ubertooth was actually one of the earlier hardware projects that existed on Kickstarter. And it was at the time it was funded. It was the highest funded hardware project that had happened on Kickstarter. Obviously now they've gone through the roof. But at the time it was quite the thing. And so people kind of came out of the woodwork to ask me like, hey, what do I need to do here? How do I need to price my product? And do you have any advice for Kickstarter? And I don't know. I probably gave some bad advice. But one piece of advice that I kind of started thinking about and continue to give to this day is to do contingency planning. And think about what will happen if you get funded to certain amounts? Like if you get funded to $1 less than your pledge goal, how will you feel about that? Will you feel relieved that, oh good, I don't have to go into production without proper backing? That will be a good feeling to have. What if you get funded to $1 more than your pledge goal? Will you be excited that you can do it? Or will you be thinking, oh no, I should have asked for more? Think about what if you get a thousand times your pledge goal? Are you going to be screwed? Is there just like no way you could possibly handle that? Because all of these things are possible and it's completely unpredictable. Well, maybe not entirely unpredictable. You must accept the fact that any outcome could happen. And if you think through, if you plan for the various contingencies for how much funding you get, then that will help you to set your correct pledge level. And maybe a more concise statement is just to say, set your pledge level to exactly what you need no more, no less. Because if you set it too high, people will look at that and think, well, they don't want to support this project because their aspirations are too lofty. And if it's too low, you can get yourself in the pit of despair and so forth. So as I said, I set mine probably too low, but I got lucky. And I should have set it up around 30K, I set it at 16K. And it turned out I got enough to make it work anyway. So then kind of that summer, I started working on what might be uber tooth 2. And this is a little prototype board called Artichoke that uses a different chip instead of the CC2400 because I had no idea whether or not the CC2400 would continue to be available. As it turns out, I have some prototypes of this board like sitting in a drawer that are still sitting in a drawer because the CC2400 is still available, so I haven't felt a real need to replace it even five years later. But I started doing more electronic design, starting thinking about more projects and kind of how the future of Great Sky gadgets would go even though I was doing this on the side. But I was getting super busy, especially as I started selling more units and getting more resellers and getting more support emails and so forth. And so I ended up in July of 2011 quitting my day job at the Boulder Labs. And this was a rather significant decision for me. I had a nice job working for the government doing research, which I love. And I was leaving it to dedicate my time to an open source hardware company. And I was basically forced into this decision by getting too busy with Great Sky gadgets. And I was working nights and weekends on Great Sky gadgets. And then during the day, during the week, I would go to my job at the Boulder Labs. And it was becoming too much. And I was forced with the decision to choose one or the other. And I had to decide I'm either going to stop doing Great Sky gadgets or I'm going to stop working at the labs. And I decided to stop working at the labs and give it a shot as a business owner. So at that time, I started kind of taking this business more seriously. Obviously, I had to take it more seriously because it had to become a steady living for me. And one of the things that I thought of when I started taking it more seriously is that maybe I needed a mission statement. And this seemed kind of weird to me at first because I'd been in companies where they would have some sort of a fluffy mission statement and it just seemed like bullshit to me. And a lot of times it is, like for example in the U.S., publicly traded companies are actually required by law to maximize their shareholder value. So whatever they tell you their mission statement is, their real mission is to maximize shareholder value. And they don't have a choice in the matter if they're a publicly traded company. Whereas I was a sole owner of my own company and so I had the ability to choose whatever mission I wanted. And personally, that was extremely important to me. And so I chose as a mission that the mission of Great Scott Gadgets is to put exciting new tools into the hands of innovative people. And that putting tools into people's hands is the goal of business has been a guiding principle that has really helped me at many occasions over the years. There have been all sorts of times when I've thought I've had an opportunity or a business decision to make and I could take the company in one or two or more directions and I've been able to make that decision because I thought which direction meets the mission of the business most closely and it's really helped me a lot. And I also kind of wrote down some guiding principles to support this mission and one of those guiding principles, kind of the number one guiding principle is open source that everything Great Scott Gadgets ever does hardware, software, content, whatever, everything we produce will be open source and that that is very important that we can reach more people. We can put better tools into more people's hands by especially innovative people who many of whom appreciate open source and will take advantage of the benefits of open source that we can reach more people by making everything we do open source but we can also reach a lot of people just by selling stuff, right? Like not everybody wants to buy things or sorry, not everybody wants to build things themselves a lot of people just want to buy something that works and so by doing both consistently we can reach the most people and also some other guiding principles to support the mission were education that is really important for the company to produce educational resources and to support educational opportunities for people to learn how to use exciting new tools and research and innovation like I don't want to spend my time and resources building something that somebody's built before I want to build something new that is innovative in some way that meets a need that hadn't been met before for example and also one of my guiding principles is just to be myself I've seen certain companies like small companies, solo companies for example that kind of put on an air of being bigger than they really are and that always looks kind of funny to me and I decided early on that I was just going to deliberately just be myself and my persona is tied to the business and just live with that and be okay with being a one person company or a very small company that is represented by me personally around this time I think it was the first time I did a Google search and stopped getting did you mean Sabertooth when I typed ubertooth which I thought was a good sign that ubertooth was a real thing once it stopped suggesting Sabertooth and I started getting more and more emails from people like idea people people who say things like hey I have this great idea for a product I just need help bringing it to market or I just need engineering or whatever and generally those people don't really have a clue there's kind of a perception and I could go into this for hours that I won't but there's kind of a perception among certain folks that there's great value in an idea for a product or an idea for a project and one of the things that I was realizing around this time especially as I was getting approached by folks who wanted help with things was that the value in an idea is really how much work you put into the implementation and how much effort you put into building something and delivering it so this was kind of tied into my concept of open source and sometimes people ask me okay so you don't do your own manufacturing and you don't do your own retail sales and you give away all your designs for everything you produce like what do you have and I think what we have at Grace Godgadget is the effort that we put into our projects and the effort that we put into supporting our tools and to promoting them and educating people about them and that the more that we put into building open source hardware and software the more value there is in Grace Godgadget the more we give away the more we get back and that has really worked out over time today there are four of us working for the company not just one and we have a brand new lab that we just moved into and we're still growing four years later in fact we went through a period of time or actually more than four years later we went through a period of time where like five years in a row we doubled revenue which is kind of plenty of growth for me thank you very much I don't really want to grow faster than that so my year ended at Turcon 13 in 2011 this particular year I'm talking about and by this time Grace Godgadget was a real thing it was still a one person company I hadn't been able to have enough revenue to hire anybody yet but I was able to keep pretty busy and one thing that I really kept busy with at this particular time was I volunteered to design an electronic badge for Turcon 13 and the original conception here was that we would give all the attendees of Turcon and Ubertooth but unfortunately we didn't really have the funding to make that happen so we didn't, you know, the Ubertooth I tried really hard to try to slim down the design to make it like the bare minimum cost to accomplish the Ubertooth function and didn't really get to the budget that we had available for an electronic badge so I ended up making an electronic badge that had the radio chip but didn't have the other stuff and so it had a radio chip and it had a super low cost microcontroller just the lowest cost thing I could possibly get and a bunch of LEDs and it did a 2.4 gigahertz spectrum analyzer function across the LEDs which was kind of cool and then it had this other section that you could populate if you wanted to that would turn it into an Ubertooth and making it modular like that where like it would have one function but then you could modify it to be this other function ended up increasing the complexity a whole lot and I had like two microcontrollers I had to negotiate with each other about controlling the other thing and like it was ridiculous I worked maybe six weeks for about 12 hours a day, seven days a week on this project which was totally volunteer just for fun just to give people out of conference and like from one standpoint it was like wow how did I waste that much time but on the other standpoint from the other point of view it was actually a pretty rewarding experience because at that time in the life of Great Scott Gadgets I had quite a bit of time on my hands and also some great things came out of it like the person who I had a couple little contests there was a badge hacking contest and then I also threw an Easter egg in there and I had a contest for who could find the Easter egg and people were doing things like reverse engineering binary from a microcontroller that had a CPU architecture that they'd never seen before and it was amazing and the person who ended up winning the badge contest was Mike Ryan who many of you may know now because he's kind of famous for his Bluetooth low-energy research security research and he won the badge hacking contest and so as a prize I gave him a fully populated badge that worked as an ubertooth and that was his first ubertooth and that's when he got started doing Bluetooth low-energy stuff and now he's gone on to do great things for Bluetooth low-energy security and awareness of it and he's contributed back to the ubertooth project a whole lot so just that one person that I reached through this crazy badge project ended up kind of paying dividends long term and I thought that was pretty cool so this was the theory last thing to leave you with here is kind of this is the theory of how the business was bootstrapped that year but this was the practice and like cash flow is hard and I've heard it said that you shouldn't really expect to make any money your first year in business and looking back at that year I'm like yeah I didn't really make any money but I was able to create something that was sustainable and that met the mission that I set out for me and financially actually the picture is a little better than you see there because what is not represented there is inventory and I started of course with nothing and I ended the year with inventory on the shelf so it totally worked out I was able to bootstrap the business kind of following the model that I set out when I did kickstarter pricing and everything and now a few years later we're still growing we have more products we're an order of magnitude plus larger in terms of revenue and everything else and we're still striving to achieve our mission of putting exciting new tools into the hands of people and so I'm very happy to say that this all worked out and that was my Ubertooth year thank you very much for coming


So, first of all, at the get go, I just wanted to say thank you very much to Wikimedia Australia for the grant that has enabled this project to proceed. Special thanks also to Linda Pascal, who's been a great partner to work with on this four-month project. I'm just going to give it a little bit of a project overview and talk about some of the achievements of the project and then I'll hand it over to Linda to talk more about her Wikimedia in residence experience and some of the particular achievements that she was able to produce during the four-month project and then some time for questions at the end. The main idea was to enhance discoverability of digital library collections at the University of Divinity where I work by using a range of different Wikimedia platforms. We were able to appoint Linda as a Wikipedia in residence because of me working in a library and having access to a number of publications related to Australian women in religion. We were able to digitise some of those publications. One was the Women Church Journal, which was an Australian journal of feminist studies in religion. So, we digitised about 40 issues of those and they were published between 1987 and 2007 and then we had quite a number of newsletters produced by the Movement for the Ordination of Women and they also had produced about three different conference proceedings and they were all digitised as well. The wider project is the Australian Women in Religion project but this project really we were honing in on women and publications that tied in with kind of early Christian feminism in Australia. So, kind of 1980s, 1990s kind of period. So, after we digitised the material at my library, we then added that content to initially the University's Digital Collections website but then we also added it to the JSTOR platform to hopefully enhance discoverability and having on JSTOR meant that we then had permanent URLs that could then provide links to reliable source material that we could then use in Wikipedia articles and then both Linda and I created and improved a number of Wikidata items and Wikipedia articles and they were both, they were related to women's groups and also some of the publications associated with those groups and then we proceeded to add those links to various Wikidata items and Wikipedia articles. When Linda and I first got together, we had a bit of a brainstorming process and we kind of divided up our kind of work so that, you know, we weren't treading on each other's toes and so Linda was, you know, way more interested in the movement of the ordination of women and sort of she just kind of went to town with that and I was more interested in the Women's Church Journal. I'd previously worked on another project where we had actually gone through that journal in a lot more detail and I'd already created a number of Wikipedia articles for women who were associated with that journal. So, this is just a screenshot of a page on JSTOR, so this is just the page for the Women's Church Archive, there were sort of 40 issues of the journal that were digitized so you obviously can click onto each item, every page then has a different URL which can then, you know, down to the article level, you can then use those links to add to Wikipedia articles. These are just an example of the kind of links that we added to Wikipedia articles and also the bottom one is in a Wikidata item. So, they tended to be in the external link section so if a woman, say, was involved, you know, was an editor of Women's Church then we would add the complete archive at the bottom and then sometimes in select publications we could just link to the particular article on the JSTOR platform. As part of the process I had created Wikipedia articles for each of the publications that we digitized, so on the Wikidata item for each of those publications we could then add full work available at URL and have the link there as well. So, we created two dashboards basically because we're working on two different aspects to the project so one was more for Linda's articles and one was more for mine and I've just recorded some of the totals there for the two dashboards together. So, the 26 articles created over that four month period that includes Wikipedia articles and Wikidata articles. There are quite a number of that we just edited and improved and you can see there the other stats. So, when I look today we're up to about 63,000 article views which is kind of a bit hard to comprehend but yeah it's all very, it's been a really interesting learning curve, the whole project. A few other outcomes for the project. Linda can talk more about her Wikimedia in residence experience and report. I've drafted an article about the whole project and hoping to submit that to a peer reviewed publication in the coming months. It was interesting to move away from the sort of biographical articles that I'd mainly focused on before and to kind of also write articles about publications and also women's Christian feminist groups as well. I did get the opportunity to present at a seminar in Brisbane in July. The seminar was called Breaking Through the Stained Glass Ceiling Women in the Church Past, Present and Future so it was really kind of spot on seminar and a lot of people there very interested in the project as well. And then I'm also presenting in November at the Australian and New Zealand Theological Library Association Conference in Christchurch. We also shared a newsletter in August about the project just kind of general information about what we'd achieved and what we were doing and then that newsletter itself was then shared on several other blog posts and other media platforms. What we haven't got to yet is the kind of the analysis of the data from looking at the digital platforms and to see if traffic does increase over time, potential to look at the referring URL to see if traffic is indeed coming from Wikipedia kind of platforms. So that's kind of next step. I think we're just kind of having a bit of a breather for a little while before we kind of then start to look at that data again. That's a very brief kind of overview of what we were trying to achieve. So I'm very happy to hand over to Linda and she can talk more about the experience from her point of view. So as Kerry said that I focused on the movement for the ordination of women then their newsletters and also the articles about the women who were danged as a result of those lobbying and also I made lots of links sort of connected up a lot of existing articles about ordination in the Anglican church in Australia and worldwide because it turns out there's sort of a lot of articles related to the ordination of women but they were kind of in silos and that they weren't very well linked so linked a lot of them up now. And you have to sort of read them all to get the whole picture and the whole history. Also I updated our Australian women in religion editing guide that was sort of just a draft. So I turned it into a beginner's guide to editing Wikipedia for future editors who might join the AWR group. I was meant to add images to Commons to add more images of ordained women and into the articles and everything but yeah we had a problem with photographs because we just we can't find the photographer of a lot of things anyway. We can't get the free license released so I haven't been successful yet in getting adding images to Commons but I'm working on it. I'm working on it. Also part of the work plan we set out a work plan was to facilitate a future editors on it. We didn't do that during the project we'll do that in the future. From April to August what I created the method I used was to create two new articles that were sort of central articles that I could then link out from and could also act as sort of almost like templates or how to write articles about Australian men in religion. So I created two new articles about two women who I could work out that they were notable enough which was another issue in this project about making sure that the biographical articles that were women were notable. I created two new articles one was Peter Sherlock and one was Susanna Payne biographical articles and the the way I kind of proved their notability was that they're both women who were ordained in the first group of women ordained in Anglican church in Australia in 1992 so that they were firsts and they also both became deans of cathedrals which is kind of the next level down from a bishop so they they achieved you know high level positions in the Anglican church so I sort of put all that together and I wrote try articles about them and then sort of practice linking out to every you know every other article I could then used as references citations a lot of the movement for the ordination of women newsletters from the 80s and 90s so the women I was writing about because they were the first women ordained and they were active in male or supported by the movement for the ordination of women I was able to find reference to them in a newsletter so I could use that as a reference and then link through to the digitized newsletter on JSTOR and I also did the created a new list and it's the first time this list has been kind of properly researched and properly published and that's the list of the women who were first ordained as priests in Anglican church in 1992 all over Australia so there was a big push in 92 to get women to be ordained as priests and there had been kind of half lists before but but they had names wrong and they had their names diocese wrong and you know they were a bit messed up so I went through the newsletters the newsletters you know had a lot of information had photos and big celebration services and all sorts of things so I was able to you know identify the proper names of all women and get the list right so I published that and then we were able to use that list as every time you write an article about one of those women we can you know blue link their name and sort of link out and so it's kind of we've made a lot of connections in the ordination of women another thing I did so so I've contributed to updated about besides the ones I created I mean I only created three new articles really but then I used that and jumped over to about 22 existing articles relating to the ordination of women and sort of updated them or made extra contributions added new sections new information to them and of course kept on adding references from the newsletters and one thing I did because I kept coming across lots of in in my research kept coming across lots of quotes people saying things about whether women should be ordained or not I started adding that to a wiki quote page so wiki quotes one of the sister projects of Wikipedia and there was a page with only one quote on it from someone about the ordination of women so whenever I came across a good quote I've added to that page on wiki quotes so now there's probably about I don't know about 20 30 quotes for and against the ordination of women and some of them are quite hysterical you know like the guy who said and he was recorded in a documentary saying this the guy who said you might as well ordain a meat pie is ordain a woman anyway there's there's all sorts of things like that but they they're all documented so I was able also to put references and citations on wiki quote and then I was able to put the wiki the wiki quote template on a whole lot of the articles related to the ordination of women so you know how you can put templates on an article that says you know see see wiki quote for more information on the subject or see comments it's got more material on the subject so I put a whole lot of wiki quote template and I've also put a lot of see also lists in the various pages so people can so I probably referenced did about 14 references to the digitized amount of use letters and we'll see we'll see where the people go to the actual digitized material another method I used to do this was to sort of mine the newsletters so instead of starting from the article of the subject I was writing about is the way to do it is to start from the newsletter itself from the digitized document and look for events or names or people and then sort of take that little tidbit of information and put it in a relevant article and then you know use the newsletters so I found by by doing that and hopefully the more newsletters bolder the names of people so it's able to quickly scan through and find names and sort of use them to write articles about those people or include those names in other articles because they did something significant and I was also able doing that to identify over time for example bishops and dioceses who were against the ordination of women and some of them changed their mind over time so there's quite a number of bishops and dioceses in the church they've changed their mind and were totally against ordaining women as ministers and now they're full on and who've ordained women and so I've kind of recorded that on their pages on some of the bishops pages that they changed their mind or the diocesan pages or the cathedral page or whatever so I've shown that you know the changes over time through history and I've been able to document that by referring again to the newsletters the four main challenges I've faced was establishing a notability of women I think some of the notability guidelines work against women artists and women in religion I think for example there's a Wikipedia guideline that bishops are automatically notable so you don't have to sort of prove nobility of a bishop a bishop is automatically notable so you can put a page about a bishop you know write an article about any bishop but the problem is that women because women in the Anglican church have only been ordained since as priests since 92 and you have to be a priest before your bishop you know there's a very small pool of women who are now bishops so that's whereas there's you know thousands of men because they were ordained as priests all year so there's just various things that make it difficult to show according to Wikipedia notability that women are notable and we sort of have to work well another thing was that I found I was alerted to the fact that I was overusing citations just just generally I made it so I've got a history background which generally we're sort of using citations and someone put a site kill template on one of my articles and we had this big discussion about the language and many so and sometimes other editors have gone through and just deleted a whole bunch of references in my articles and I've had to go back and find them again and rebuild them and so that was something that I experienced and so I've had to go back and think about if I used too many citations and change some of my articles and delete some no free license photos that was a challenge but one of the big challenges is of course that this the ordination of women is still a live topic and it's still a controversial topic in some areas in the Anglican Church in Australia and that can lead to some some sort of discussion on talk pages and some reference sources that people have been using articles about the ordination of women some reference sources are really dodgy because they're they're against the ordination of women and they sort of vilify women priests so I've had to delete a whole bunch of those kind of sources and you know they're halfway to getting blacklisted as a source but anyway so this the Infra-Church politics is still happening about whether you should even mention the ordination of women because you know some people don't like it so um I like if the whole project for me was that on the 12th of August a bishop in a diocese changed its mind decided that it was a good thing if they ordained some women and so on the 12th of August there was a live on YouTube you could watch it a live service where this bishop who had previously been against the ordination of women decided that he could ordain these women as priests and so it was live streamed and so that was great a lot of people watched the live stream of these women being ordained and I set up a section in my a draft in my sandbox ready to go with the names of the women and what happened and how this bishop changed his mind everybody ready to go so at the end of the service the minute I put that section I updated that um page that diocese page or bishop's page and everything can say you know they used to be against ordaining women but now the change in mind some they ordained these three women and here you can even go and watch it you know and had external links in the references external links section that people could even go and watch the YouTube live stream of it at the same time that same day 12th of August at 11 a.m another um diocese installed a woman dinging in their cathedral so I watched two screens at the same time I watched both services on two different screens one on the television one on my computer and I had her information ready to go so as soon as her installation service was over I updated the cathedral page where the deans were usually listed and added her name as a dean so that that was really fun for me to do live updates history


heat capacity is amount of heat absorbed by 1 kg of substance is the amount of heat absorbed by 1 kg of 1 kg of substance increase a temperature by 1 degree Celsius. So, s should be equal to 1 delta q divided by m into delta q. Now, delta q will be equal to m s delta t by definition itself. Now, this specific heat is different for different material for iron it is something else for copper it is something else like that getting it. So, if temperature is increased heat will be absorbed if temperature is decreased same heat will be released. So, if you already know that the decreasing temperature is like release of heat and increase of temperature is absorption of heat you do not care about the sign coming in you always subtract lower temperature from higher temperature you take the modulus of it. Let us suppose changing temperature is 5 degree Celsius whether it is increase or decrease the quantum of heat is same whether it is released or absorbed. So, that is how you deal with and then you find out the heat involved in the process m s delta t any doubt here no I think this concept was introduced in class 10, 9 in chemistry m c and c v delta t that is molar specific heat. Now, this specific heat capacity is a very good you know physical parameter for liquids and for solids for gases the situation becomes little tricky. The problem is this let me give you an example suppose you are cooking a food inside a pressure cooker and suppose you are cooking food in an open utensil where the food will be cooked faster pressure cooker why because temperature increases faster inside the pressure cooker same gas is there same gas it mostly gas only is there, but it is able to increase its temperature more if it is inside the pressure cooker with the same amount of heat what is so special in the pressure cooker? The volume is constant when it is open utensil what is constant pressure is constant. So, for gases we need to also take into account that whether it is a constant volume or constant pressure process constant volume specific heat is different constant pressure it is different you learn more about it in thermodynamics what happens is that the some amount of heat with gas absorbs goes into expansion when you are allowing it to expand but when you are enclosing it it cannot do any work whatever heat you give entire heat gets converted into rise in temperature of the gas fine. So, that is the reason why same amount of heat when you good when you give in constant volume the rise in temperature is more. So, now tell me where the specific heat capacity will be more in constant volume or in constant pressure same amount of heat let us say I am giving delta q delta q at constant volume delta t will be more at constant pressure delta t is less delta q by delta t is more in constant pressure. So, at constant pressure specific heat of gas is more and when we talk about gases generally we like to deal in moles that is why the heat capacity is not defined per kg of a gas but per mole of a gas and we call it molar specific heat capacity. If you call it specific heat capacity it is still per kg only you have to specify it is molar specific heat capacity. So, what should be the formula at constant volume molar specific heat is written as C v which is equal to delta q divided by what n into delta t n is number of moles this is C v heat is supplied at constant volume C p is delta q p divided by n into delta t. So, if I give let us say one joule here delta q is one joule here also one joule which delta t will be more this or that constant volumes delta t will be more this is pressure total like scenario delta t is more temperature rise is faster. So, denominator is more than this denominator that is why this is lesser than that C v is more than C v write down calorie metering is what a unit of heat energy in a way metering is measurement it is like measuring something. So, measurement of heat is calorie metering is a process of measuring the heat. So, in the calorie metering we will learn about an experiment to measure the heat itself or this experiment will help you calculate the specific heat of particular substance. Have you ever heard of calorie metering term before you are in C v s your ice case do you see you see calorie metering uses a bucket sort of thing that is called calorie meter. So, you have this calorie meter it is made up of an insulating material you may want to put the foam inside or make it upward. You are doing it so that there is no exchange of heat from the sounding whatever happens inside remains inside then you have to put a lid also at the top and then let us say it has water. Now, you are going to measure heat. So, what is the first instrument you should have thermometer right there is a thermometer which goes like this this is thermometer you may want to open the lid and then drop a very hot iron ball inside. So, that heat is getting exchanged between iron ball and water and based on that you draw some inferences. But, when you do it when it goes down may be water this side is hotter that side water is colder temperature is not uniform then what you should need stirrer. So, you have a stirrer also it will just mix everything fine. So, this is the calorie meter inside which you have exchange of heat which is happening and the best part is there is no exchange of heat from the sounding that is assumption actually there will be some exchange of heat anyways. But, then what will happen inside the calorie meter there will be some hot objects right down there will be hot objects before mixing and talking like for example, this is a hot iron ball there will be hot objects and then there will be cold objects of course, hot and cold they are relative term. So, I am saying the temperature difference is there. So, now, when they are coming in contact and you have a stirrer also what will happen exchange of heat hot objects what they will do they will lose heat to lose heat energy and what the cold objects will do they will gain heat energy. Now, is the magnitude of loss in heat energy is equal to the magnitude of gain in heat energy yes or no it will be right this is how you this is nothing but conservation of energy only. This is how you use calorie meter to measure the heat you just equating the amount of heat that is lost by the hot object with the amount of heat that is absorbed by the colder object. Now, when you leave it like this when the hot object comes in contact with the colder object and you with the stirrer do all that and leave it for very long time what will happen temperature becomes constant both for hot as well as cold both will come at the same temperature initially they may be having different temperature but finally they will come at the same temperature it may happen that in a numerical it is given like for example X amount of heat is given out to the atmosphere then I think you are intelligent enough to equate right you can say that whatever heat hot object is releasing that is equal to gain in heat energy by the colder object plus loss to the atmosphere right but majority of the time they will not gain in loss to the atmosphere okay so all we have to do in a numerical related to calorie meter is equate loss in heat energy with gain in heat energy we lose the heat energy hot object and we will gain the heat energy colder objects very simple okay shall we do a numerical treatment for delta q is what m s delta t fine till now our assumption is we are not changing state it will never happen that right now I can you know I can put an ice also its state will change it will become liquid right I am not touching that scenario right now I am just talking about scenario where the states remains same if initial state is liquid the remain liquid if initial state is solid remains solid now tell me one thing there will be hot object there will be colder objects calorie meter is this bucket let us say okay which will have a proper coating inside will this calorie meter also absorb heat or release heat current does it can do it can right so you need to take into account the calorie meter also fine so initial temperature of calorie meter will be the temperature of all the objects inside the calorie metering initially and the final temperature of calorie meter will be the final temperature of everything which will be constant for all okay at times it will be given that calorie meters water equivalent is 100 gram what does it mean it means that calorie meter will absorb same amount of heat as if 100 gram of water would have absorbed fine understood so all these final nuances will be there in problem solving may not be at your school level but when you solve jail your question there will be such new answers okay


Hello everyone, in our day-to-day life we get an opportunity to learn many things from both living and non-living objects and if we have keen observation we can learn lot of things and also if we learn something good that we can pass it on to others. That means irrespective of our age, irrespective of our profession we have lot to learn every day and hence I say learning never ends. So with this let us continue learning chemistry, especially chemistry of transfer elements. So today's focus would be on Ligand field theory and until last lecture I was discussing about the crystal field theory and its utility in understanding coordination chemistry and why people switched to Ligand field theory. Let us try to understand to accommodate and account for both ionic and covalent characters in metal ligand bonds. Ligand field theory was introduced and it is a combination of best part of valence bond theory, crystal field theory and Mulliken's molecular orbital theory. So let us try to conclude crystal field theory and its advantages and considering. Let us try to understand crystal field theory's simplicity and how it differs from Ligand field theory and what is Ligand field theory. Crystal field theory of course is a simplest model for explaining the structures and properties of transform metal complexes. The theory emphasizes mainly on simple electrostatic interaction between the metal ion and the Ligands and considering Ligands as point charges. Although some of assumptions made or inaccurate it is still very simple to understand and also useful because of its effectiveness in using molecular symmetry. It describes the properties of metal complexes such as color, magnetism, geometry and relative stability of complexes having different type of Ligands quite accurately. However, Ligand field theory is more advanced and it is originated from molecular orbital theory. It is more complex compared to crystal field theory but it is more accurate and Ligand field theory will explain many questions accurately that crystal field theory may not from this context and it is very appropriate to bring in Ligand field theory concept instead of crystal field theory to understand or to for better understanding of coordination compounds and their properties. Ligand field theory very effectively uses molecular orbital theory in coordination chemistry by giving importance to the effect of donor atoms that is the Ligands and the energy of d orbitals in the metal complexes. Same thing we observed in case of crystal field theory also the direction of approach of Ligands how they influence the energy of d orbitals. The influence of Ligands on the d electrons on a metal can be analyzed from Ligand field theory of point of view in two ways electron electron repulsion and of course this is due to the lone pairs from Ligands when they start approaching the metal ion and bonding interactions between the metal and donor atoms. The combined effect increases the energy of the d electrons which in turn depend on the nature of Ligand field and the geometry is conferred by them at the metal center. From crystal field theory we know that in an octahedral field eg orbitals that is dz square and dx square my y square interact strongly whereas t2g orbitals does not interact so strongly but rather weakly. Therefore these two orbitals along with Ligand orbitals from new bonding therefore these two orbitals that is dz square and dx square my y square along with Ligand orbitals form new bonding and anti bonding orbitals. The other three orbitals that are present on metal center that are dxy dyz and dxz that is t2g will remain as non-bonding with almost unchanged energy. Of course these assumptions we made in crystal field theory as well and then let us consider octahedral complexes. In octahedral complexes the electrons of the Ligand occupy all 6 bonding molecular orbitals whereas any electron from the metal cation occupy the non-bonding or anti-bonding orbitals. Non-bonding means it is t2g or sometime anti-bonding means it is eg especially when the metal ions have more than 6 electrons in their d orbitals. The separation between t2g and eg orbital is designated as the orbital Ligand field parameter delta O similar to what we call it as crystal field stabilization energy. So Ligands whose orbitals interact strongly with the metal orbitals are called strong field Ligands for such Ligands the orbital splitting is little larger. In contrast Ligands whose orbitals interact only weakly within the metal orbitals are called weak field Ligands for such Ligands the orbital splitting is very small. So that means still the concept of weak field Ligands strong field Ligand is continued in Ligand field theory. The other comparisons between various d configurations and strong and weak Ligands are very similar to what we come across in crystal field theory. When we talk about Ligand field theory it proposes two types of bonds known as sigma bonds and pi bonds for coordination compounds similar to what we see in organic chemistry or main group chemistry with the aid of valence bond theory. The sigma bonds are symmetrical about the axis of the bond whereas pi bonds are unsymmetrical with regard to the bond axis that we should remember and of course the same concept we use in valence bond theory also while explaining organic molecules. Again in coordination compounds pi bonding may result from donation of electrons from Ligands. For example halogens or oxygen atoms to empty d orbitals of the metal atoms especially in case of early metals in their high oxygen states where all the d orbitals are empty and they are halophilic and oxophilic in nature are electrons from d orbitals of the metal to appropriate empty orbitals of the Ligand as in the case of metal carbonyls such as chromium carbonyl, chromium hexacarbonyl, iron pentacarbonyl or nickel tetracarbonyl and other carbonyl compounds or carbonyl clusters. In the chromate ion if you consider CRO 4 2 minus the oxygen atoms donate electrons to the chromium ion which is in plus 6 oxygen state having no electrons at all in the d orbitals. In case of carbonyl and phosphine complexes electrons from the metal orbitals especially T2g may be donated to empty pi star orbitals in case of carbon monoxide or sigma star orbitals in case of phosphines. This is also known as back bonding and such Ligands are called back bonding Ligands, pi donor or pi acceptor Ligands. So now with this information about Ligand feed theory and how it was slightly modified concept it uses from crystal feed theory can be understood and using this theme let us try to do the classification of Ligands. I shall tell you of course I will be discussing the classification of Ligands by donor atoms after couple of lectures but now for convenience with the help of Ligand feed theory let us try to understand how whatever the Ligands we have at our disposal can be classified for simplicity and for better understanding to make a coordination chemistry much simpler than what it looks like. And I was telling you the main drawback of crystal feed theory is it does not identify the system where metal is neutral and Ligands are neutral. In that case what happens metal if it is neutral it can also generate a dipole and of course Ligand neutral Ligands can always generate a dipole because of electronic humidity difference between the donor atom and the peripheral atoms. In that case what happens when the metal Ligand bond takes place that would be like dipole-dipole interaction according to crystal feed theory if you give emphasis for electrostatic attraction. In that case it would be dipole or dipole interaction as we see in case of nickel tetra carbonyl or chromium hexa carbonyl or other carbonyl complexes. But crystal feed theory does not explain about the nature of the bond having fully covalent property. So that means in order to introduce both covalent and ionic character Ligand feed theory came into existence and based on this theme let us try to classify whatever the Ligands we come across into broadly three categories. So that I shall show you of this slide. The most common one is Ligands comes with a pair of electrons that can be readily donated to the metal. So here Ligand is a two electron donor and all Lewis bases are considered as this type of Ligands ammonia, water, carbon monoxide and triphenyl phosphine. And then what happens here you can see Ligand is one electron donor both metal and X is a Ligand here contribute one electron each. So that means radical such as H, Cl and CH3 are considered as this type of Ligands. And in the last one metal has sufficient electrons and acts as a Lewis base and that interacts with the Ligand which is not Lewis base but Lewis acid. In that case Ligand Y is zero electron donor both the electrons are from metal they are called Lewis acids and examples are BF3 and ALME3. And again this type of system we can further classified into three categories and by considering both donor and acceptor properties of Ligands as I mentioned in case of chromate or carbonyl complexes and how this donor and acceptor properties of Ligands fluently crystal field stabilization energy let us look into it from these diagrams. You can see here we have the metal the metal orbital energy somewhere here and the Ligand is a pure sigma donor here and the energy is relatively lower compared to this one and when they interact this is the magnitude of crystal field stabilization energy here. That means we are interacting metal with low energy sigma orbitals low energy sigma orbitals that are filled to be precise the metal is interacting with filled low energy sigma orbitals of the Ligands in this case this is the magnitude here. Example you can consider pure sigma donors ammonia and water let us look into the second case here. So in this case we have these Ligands which have low energy field sigma orbitals and low energy field pi orbitals if you consider halides such as chloride bromide iodide they have S2 P6 electronic configuration and eight electrons are there and that means completely filled wear and shell when they interact with metal they come up with low energy filled sigma orbitals and low energy filled pi orbitals in this case what happens because of their interaction what happens CFSC decreases relatively compared to what we see in the first case. You can see drop in the magnitude of CFSC that means we can know between them which one is relatively stable and which one is relatively less stable. Now the second third case is we have filled low energy sigma orbitals and MT high energy pi orbitals when such Ligands are coming to establish a bond with metal this is what happens here the magnitude of CFSC increases that means any Ligand that is sigma donor and pi acceptor having low energy field sigma orbitals and high energy MT pi orbitals. So they stabilize complex to a greater extent and hence they are called as stronger Ligands because CFSC is larger. So this is how you can classify the Ligands and this is how you can tell why a particular Ligand is called as weak Ligand why a particular Ligand is called as strong Ligand. Christofield theory says classifies Ligands according to spectrochemical series and also gives authenticity through electronic spectra showing the relative Christofield stability energy and shows why one Ligand is weaker one another Ligand is stronger but the explanation lies here. If I say why chloride is a weaker Ligand compared to water we should not say CFSC. CFSC is a authenticity it gives a evidence but it does not explain why in order to explain why a Ligand is weaker compared to other one we have to classify according to these three categories and we have to see where exactly the given Ligand falls. It has to fall into one of these categories if it falls here we can explain yes it has a low energy field sigma orbitals and high energy MT pi orbitals as a result what happens this is what happens to the CFSC in the same way we can explain. So this explanation gives precise meaning to the position of Ligands in the spectrochemical series. So this is pure sigma donors and they are pure sigma donor and pi donors and they are called sigma donor and pi acceptors and examples I have already given here now in case of all Ligand system will come under one of these classes their positions in the spectrochemical series is based on these properties and if somebody asks why a Ligand is weaker you should not tell because CFSC because CFSC is an evidence through electronic spectra means but it does not tell you why. So this will give you satisfactory answer for why these Ligands have this kind of different properties and of course on a later note we can also compare into something that we are observing day to day life for example here is a person who earns enough money to take care of his family when he has a student school going student what happens he takes care and he gives enough money for his school and all those things without any problem and the student becomes good and he learns properly and he achieves what he wants this is in case of pure sigma donor Ligands and then here father is business minded he earns lot of money you can see it is almost like minting money and then what happens he does not have much time to worry about his son or daughter and when he goes to school he will be giving whatever the money he has double so that he should not bother him on the other hand since he has lot of money mother also gives lot of gifts in that case what happens he does not show any interest because he has lot of money to spend and as a result he becomes something like this this is what happens to metal complexes having sigma donor and pi donor they are very very reactive and labile that is the reason when you take unhydrous metal halide and keep it tomorrow what happens it appears like wet because what happens the atmospheric moisture steadily replaces and it forms hex aqua compound that means very unstable and the other hand he is very intelligent person and he knows how much money has to be given including his fees and pocket money whatever and he gives but mother is even more clever she thinks that father has given more money to the student and she takes little money from him for future and as a result what happens this student understands value of money and and he puts all his time for studies and the student becomes a plus that means very stable so everyone should be like sigma donor and pi acceptor ligands so that they can achieve whatever they want without any problem and examples in this case are all kind of tertiary phosphine carbon monoxide olefins and heterocyclic carbons and all those things of course I shall discuss and give relative comparison of all sigma donor and pi acceptor ligands at later stage. Now let us come to molecular orbital theory as I mentioned ligand field theory has embedded best parts of valence bond theory crystal field theory and mullicans molecular orbital theory so before I introduce the ligand field theory I want to make you familiar with molecular orbital theory so that understanding ligand field theory would be very easy and for that one I have given some points here molecular orbital theory is based on delocalized bonding model unlike valence bond theory and similar to isolated atoms a quantum mechanical treatment is adopted for molecules and uses the concept of molecular orbitals considers the wave like properties of matter. A molecule is considered on a quantum mechanical level as a collection of two or more nuclei surrounded by delocalized molecular orbitals over the surface of two nuclei atomic wave functions are some to obtain molecular wave functions if wave functions reinforce each other a bonding molecular orbital is generated or formed and it is nothing but the region between the nuclei where high electron density exists on the other hand if wave functions cancel each other an anti-bonding molecular orbital is formed that means a node or a region where zero electron density exists between the nuclei. So this is how you can represent summing up and subtraction so here you can see the electron density resides here when the waves are reinforced on the other hand when the amplitude of waves subtracted so you can see a node between two electrons this is called anti-bonding and this is called bonding. So contours and energies of the bonding and anti-bonding molecular orbitals in H2 I am going to show here you can consider two isolated hydrogen atoms having one electron in their 1s orbitals when they interact as I mentioned two levels are generated one is due to subtracting and one is due to addition and energy of isolated atoms remains here and now the bonding molecular orbitals are generated where you can see two nuclei are there and between electron density resides this is called sigma 1s and this is anti-bonding where we call sigma star 1s all anti-bonding will be given the superscript star next to it so node is generated here this is called anti-bonding and of course this is very very important the symmetry classes of SP and d-orbit of the central atom of an ABN molecule with respect to the point group in most cases the z axis is principal axis of the molecule so whatever the molecules we are considering where in coordination chemistry or in a just always we keep z as principal axis for example if I ask you a question to write crystal field splitting diagram for a molecule okay octahedral molecule or a square panel molecule kept along x axis if a molecule is kept along x axis instead of z axis then it will be in y z plane then accordingly what happened the splitting varies so one should be able to understand these aspects if you understand these aspects you should be able to write crystal field diagrams no matter which axis we are considering as principal axis so nevertheless here we have considered z axis as principal axis and when we consider according to various point groups what are the mulligan symbols we are giving and what is the nature of bond we come across for various orbitals I have listed here this is very good very informative and there is no need to remember this one okay just whenever you get time go through this one to understand the terms we are using for different orbitals under different point group for example if you consider tetrahedral or octahedral s orbital is symmetrically spherically symmetrical and it forms sigma bonds and we say it is a 1 g so same thing is there and p orbitals p x p y p z or degenerate we call them with t 1 u that you have seen or you are going to see okay and then dz square and dx my square we call eg that is what is here and dx y dy z and dx z collectively called t 2g so these are the terms we are using and again in case of td because of lack of centrosymmetry we remove the g and that holds good here we can say of course pr build some variation will be there and if you take d 4 hat for square panel complexes you can see whatever the no mullican symbols we are using you will be coming across in ligand feed theory as well as in molecular orbit theory and then yeah this is for octahedral and this is for tetrahedral complexes geometry and this is for square panel and then I have just expanded what is that one what is mullican symbol a means singly degenerate or one dimensional symmetric with respect to rotation of the principal axis because of it is a spherically symmetrical nature it is symmetric with respect to the rotation with respect to any axis for that matter and b singly degenerate or one dimensional anti symmetric with respect to rotation of the principal axis on what basis we have given for example if you want to try to see a particular orbital and with respect to a geometry you can understand whether the statement is true or not and e means doubly degenerate or two dimensional e g we are using so t mullican symbol triply degenerate or three dimensional so that we use in case of t2g and subscript one if you use like a1g b1g or b2g one means symmetric with respect to the cn principal axis if no perpendicular axis then it is with respect to sigma v in some molecules will act a perpendicular axis in that case we have to consider this one with respect to sigma v and subscript two means anti symmetric with respect to the principal axis if no perpendicular axis then it is with respect to sigma v again and g means symmetric with respect to the inverse that means if they have center of symmetry and subscript u anti symmetric with respect to the inverse so this is the explanation for various superscript and subscript we come across for various mullican symbols. So let me stop at this juncture and continue discussing molecular orbital theory to make you familiar with understanding for simple molecules and also a couple of very interesting main group compounds and then I switch over to ligand field theory to explain the bonding in various transformational complexes for various geometries until then have an excellent time reading chemistry.


Just driving here to Be'Chemesh, the new Ikea outside Jerusalem with the new Ikea and this road from Jerusalem passes through tons and tons of forestry. Under normal conditions the forests are very green and verdant but if you take a look around you can see the devastation that has been wrought by these forest fires that were burning all over the Jerusalem hills for the last week. Now they're only officially declared extinguished I believe about a week ago and even in the period since then there's been talk of another fire outbreak and what you can smell through YouTube is the smell, the strong smell of burning that is still actually in the air in this area and it's a smell that unfortunately for those of us living in Jerusalem has become very familiar over recent months because it literally gets from here which is outside Jerusalem and in this forested area all the way into the city. I made a video on this channel last week of those plumes of smoke blowing into the air and if you just look at there's a tree here this is just one of the burnt trees right behind me here and you can see that it's just like burnt as if you held it over a barbecue.  So under normal circumstances this whole area is beautiful and green and right now in parts here it's burnt and in parts here it's green and this is the forest outside Jerusalem and these forest fires I don't believe the cause has been determined yet but we're seeing them all over Cyprus, Greece and Israel and probably as global warming continues and other other factors are going to be seeing more of these in the years to come.


I'm Mary and I'm a tripscape. So that's why I'm here to talk about how to over-complicate a home network without spending too much money. And yeah, part of my presentation style, I can never get anything pretty, so I just don't try. So when I'm being a complicated network, I don't really mean this. Yeah, that's what VLAN stuff is for, you don't need all that. And you certainly don't need all this either, which is what I had a while ago. I hope you guys can see that from back there. So why do I want to complicate a home network? Well, I want to run a service and I have a housemate. So separation between service and quality of service are pretty high on my list of priorities. And until I get on the national board, but no yes, Control. The problem was it was explaining too much. So control alt. Control shift. If we do that and then maximise it, maybe we can... Yeah, that looks better. Can we get rid of one of the tabs and then... Okay, there you go. That's okay. Let's just close one of them. Okay. Okay, that looks better. Except I can't throw in this. Technology. So yeah, yep. So until I get on the national board by network with unlimited quota, my housemate is going to have to live with traffic-shaping. And...  And he picked the latter, so... Yeah. Public IP address is actually quite cheap nowadays. I'm paying about $130 a year for block of slash 29. So which is quite cheap, which I use for my service. So this is a list of my hardware components. My OpenBSD router comes to about $170, which is cheaper than most of your second-hairs Cisco gear. And I have a Linksys modem. It's quite a big chunk of change in there, but it's not useful at the moment because I just have it in bridge mode. It was good back in the days because it has 64 megs of RAM and 16 megs of flash, which is pretty good for BitTorrent. See, the modem doesn't die after like two days. And I also have a managed switch. This re-badged Linksys, I know this is Cisco, but it's actually re-badged Linksys. I actually got it for under $100. I thought it was a pretty good deal for a gigabit switch which was 8 ports, although I think right now it's around $150. So in total, it's only a bit over $300, which is actually a lot cheaper than my second-hand Cisco. 1841. So this is what it looks like, logical-wise. So there's a pointer. So that's my DSL modem here. It just runs in bridge mode nowadays. And down here I have my OpenBSD router. It does PPP over Ethernet session to my ISP, which is TPG. And we all love IPv6. So I have an IPv6 tunnel. And this is the most central part of my network. It has all the VLANs configured. So I get my separation between all the hosts.  It doesn't really do much at the moment, and it's a pretty cheap thing, but I have it there because I prefer to use WIDE for my laptop and I don't really want to run a 30-meter Ethernet cable between my room, which is where this is, and this thing's in the living room. And this is an wireless access point, which is where my housemate uses to get online, and obviously the phone and the Wii connects to it. And this thing here is my Linux desktop. It runs VMware server and has all the VLANs configured, so I have this pretty little virtual switch there. So why OpenBSD?  It was a lot better than IP chains when I first started to use it, and it has nice out-of-the-box features like traffic shaper, load balancer, and stuff like that, which I know you can get modules for IT tables nowadays if it's not already built in, but if it ain't broken, I ain't fixing it. And it's also really stable between releases. I started using it when it's 3.2 or something, and the really big change I've noticed, well, the only one rather, was between 4.6 and 4.7 where they changed the syntax of the packet filter rules. And I love that last one. Only two remote holes. That makes me really warm and fuzzy inside. So VLANs, complex networks, need complex separation. So what I've done is I've mapped each VLAN to a public address and an IPv6 subnet, which is a Static64. So I've created trunks to the router and from the VMware server, which is pretty easy, just clicky-clicky on the links switch. And obviously, I need to do interval and routing on the OpenBSD router. So on OpenBSD, it's this file here. You just first configure the IPv4 stuff. So the address subnet, this is the broadcast mask, non-mix just derived from NetMask and also the VLAN stuff. And since I use IPv6, I just alias an IPv6 address on tour and prefix lens of 64. And on Linux, I just do pretty much the same thing to create the VLAN interface. I know most people prefer using the vconfig command, but apparently that's defecated according to what Google says. And that, this is my favorite part because I have so many IP addresses. This is packet filter config under OpenBSD. So I have my definitions up here of my various public copy addresses. And then I make the VLAN definitions as well. So each VLAN is a slash 24. And then I have the NAT rules for each VLAN. And notice how here I have the static port settings for this VLAN. This is because Nintendo Wi-Fi connection is really anal. And the static port setting tells packet filter not to translate the source and destination. Wait, no, just a source port for TCP and UDP packets. And without that, I figured that all TCP dump actually says a lot of UDP port originals and yeah, Nintendo Wi-Fi doesn't work. And by the way, this is OpenBSD 4.7 syntax. IPv6. Well, obviously we're running out of IPv4 addresses apparently. And IPv6 is also really fun to play with. So I got an IPv6 tunnel from iNet via the broker service. I had a slash 48 back in the days, but I forgot my password. So a slash 56 is still pretty good nowadays. So what I've done is I've assigned a slash 64 for each VLAN, which is just enough on this slash 56. And I quite like doing that because Stateless Autoconfig needs to have a slash 64 for the prefix length in order to work. Although I don't really do that on all of my VLANs because Stateless Autoconfig can be kind of evil because it sticks to your MAC address in there. That applies for most of the Linux implementations and also for all Cisco devices. So yeah. I'm kind of paranoid in case you haven't noticed. The IPv lens gave that away. Well, but you still did get the MAC addresses if you're outside my network. So yeah, firewall, that's really fun because complex network comes with complex firewall rules. So a lot of the stuff depends on the firewall rules that applies to inter-VLAN routing. So like I mentioned before, I want separation between our servers. So the hard part is that our server needs to be able to talk to the internet but not to each other unless they explicitly allow it to. So I also need rules for both IPv4 and IPv6 because Autoconfig is so nice and easy to use.  And yeah, too paranoid for that as usual. So here's a snippet of my firewall config. So I have definitions up here and definitions for VLANs. And here are some examples. This one says allow pings from these VLANs to each other and this VLAN can connect to SSH and this VLAN here has some freedom with IPv6 traffic. And obviously down here I have a default block call. And here's my Linux desktop specs. I'm running on time so I won't go through that. But it's a quite beefy box that I built a few years ago because I knew I was going to run some virtual machines. VMWare server. I love VMWare server even though it's only free as in bare not free as in openness. But it's quite nice because management wise it's really nice with the clicky clicky stuff which I like. And I don't really like virtual box because it doesn't let me do a lot of things like reverting snapshots while it's powered on. And I quite like this interface because I can change VLAN associations just with the drop down menu and I can do that while the host is powered on. And here's my list of encountered issues and yeah I've spent many weekends geeking out trying to figure things out. So the first problem was pretty easy to fix free as in bare software doesn't get maintained very well. So this problem here was the VLAN tag because VMWare grabs the tag by the frame off the wire before the tag gets stripped. So simple changing code. Tell it there's the VLAN header. It's okay. Just deal with it. And then it works. And problem two. I actually didn't notice this problem for a while. What happened was I kind of noticed my traffic going out one way which is E0 and then coming back from E1 I'm like well that's not supposed to happen because my default gateway is set to E0 so it turns out that Linux has this art filter turned off by default so that my router actually had the wrong MAC address in this up cache. So after I turned the filter on it was all good. And the third problem I spent ages on I just had no idea why VLAN tagging wasn't working and the moral of the story is it's because I was using ancient software. That installation of OpenBSD had been dd'd across three hard drives and two physical boxes. Yeah so I had an excuse to upgrade. And to-do list my SP office IPTV so I got to set that up sometimes. And then I want to put SE Linux on all my public-facing servers because I've recently gained an appreciation for it. It's actually quite nice, although complicated. And notice how I didn't put the cost of a hard disk in for my router. It's because I plan to pixie boot it anyway so it's going to be a disk list system. And lastly I want to set up my Linux box the one that runs VMware server wireless access point because Google is kind of evil. Sorry to the Google employees here because I don't really feel warm and fuzzy inside knowing that my wireless router's MAC address can be associated with my location down to like 200 meters radius. And I noticed also that having a hidden SSID doesn't help. So yeah, that's why I want to bridge the wireless interface to one of the VLANs. And then at least on the Linux I can soft change the MAC address easily. And my favorite MAC address is dead-beath-dead. And yeah, I really need a term for all that. So yeah, there we go. That's the end of our talk. Thanks.