VCO - Eurorack modules

Sync VCO

$25 Hard/Soft SYNC VCO - DIY Eurorack Modular Synthesizer
The Arduino UNO R4, released in 2023, is equipped with a DAC and has a 5V input/output circuit, making it easy to use for modular synths. This time, I created a VCO module to verify the usefulness of the Arduino UNO R4 for modular synths.
Analog VCOs have a function called oscillator sync. This is one way to reset the waveform according to the external SYNC input and create a waveform with many harmonics. I have created many VCO modules in the past, but I have never created a VCO with oscillator sync function, so I planned to create one this time.

A Flint ProMicro R4 board is used in this design. Not available for sale in Canada, it was ordered through ZenMarket.