project Technology › Discrete 8-bit DAC
A resistor ladder for an Arduino UNO
A DAC that I built for my Arduino UNO from an Instructables video. It's essentially a voltage divider for each pin of a microcontroller, which lets the digital chip send audio out at whatever sampling rate the pins can clock, since each bit gets its own wire.
It's what got me into audio DSP and working with audio buffers, since I am enchanted by standalone audio processors like pedals. This is basically a reconfigurable digital-effects interface: plug line-in to a microcontroller analog input, and get a line-out with no DAC chip.
It was incredible to see how much could be done with an Arduino UNO. The thing barely has any compute power, yet it can process samples in and out at 38 kHz (although this takes a beating depending on how heavy the processing is). It's even more limited in RAM, but I managed to implement an audio delay, with duration controlled through downsampling.
I later made one as a gift to a friend. It looks more put together than mine, and I gave it some consumer protections like taking +/- voltage in. And a little Kid A themed laser-cut wooden box for my Arduino UNO.
