Whether you have full use of your hands or not, a foot-operated keyboard is a great addition to any setup. Of course, it has to be a lot more robust than your average finger-operated keyboard, so ...
If you have an interest in electronics and have been hanging around DIY tech forums for a while now, chances are you already ...
An LM358-based op-amp magnifies the current induced by the machine and feeds it to an Arduino Nano, which does FFT calculations. [Marco] found a high-voltage interface driver to switch 170 V to ...