Why buy an air quality monitor when you can just make your own? Even if it costs about the same, having the ability to modify ...

[mircemk] shows how to create a simple non-contact proximity sensor using little more than an Arduino Nano board, and a convenient software library intended to measure the value of capacitors.

Because of that, and to make the design more flexible, several versions of the board have been made to accommodate the different permutations of: [Andrew] not only designed the sensor but has done ...