Scratch Away With Lo-Fi DIY Turntables [How-To]

<p>You can finally repurpose that old cassette player.</p>

Nov 29 2011, 8:32pm

Do you dream of becoming the next Richie Hawtin or DJ Shadow, but don’t have the necessary gear (or the money to drop) to hone your skills? If you’ve experimented with the wristwatch turntables, but want to take it to the next level, then you may be interested in this How-To from Adrià Navarro, a masters student in NYU’s ITP program.

She fashioned these turntables from a PC fan, a cardboard box, and hacked a walkman to play cassette tapes in tandem with the speed of the fan, all powered by an Arduino housed inside the cardboard box. She also added LEDs to show the speed of the music visually.

Navarro’s initial idea was to have the fan acting as input and output at the same time, so it would be rotating at all times to the speed of the music (output), and also able to be slowed down or sped up to control the song (input). To make that happen, you have to read the rpm of the fan through its third wire as explained in this tutorial.

Navarro took a slightly different approach and ended up using the fan’s motor as a generator in order to measure the amount of current generated by the manual rotation of the fan. But she warns not to plug more than 5V to an Arduino pin—if for some reason you generate a higher voltage, use a voltage divider.

It seems the most difficult part of the project was writing the correct voltage to the cassette player, so Navarro provides some tips: 1. The minimum voltage needed to start the motor is higher than the one needed to keep it running once started. 2. The amount of current affects the motor even more than than the voltage, so analogWrite (150) behaves differently depending on if the Arduino is plugged into a computer, a 9V battery or a power adapter. 3. At certain voltages the motor isn’t powerful enough and produces an annoying sound.

Check the slideshow above for photographs of the build, and if you already have your own turntables, learn how to DJ like Hawtin below.