“This is a memorandum about HAGIWO/ハギヲ using seeed Xiao rp2040 and rasberry PI rp2040 to make your own VCO for the modular combiner.
53rd self-made modular synth.I took a poll on my Youtube channel and the Rasberry pi pico VCO was the most popular. However, the Rasberry pi pico has only 3-pin AD converter, and I was worried that it was a little inconvenient to use it as a VCO.
Under such circumstances, Seeed studio released a small microcomputer board called Seeed Xiao RP2040. Since the AD converter has 4 pins, I thought that I could make a VCO with a minimum configuration, so I planned this module.
Eurorack standard 3U 6HP sizepower supply: 45mA (at 5V) Canoperate with a single 5V power supply.
Digital VCO with 3 modes: Wavefold, FM and AM.Audio output uses PWM to reduce costs.Each mode has 8 built-in waveforms.
FREQ POT : Adjust frequency. Since it is for tuning, the adjustable frequency range is narrow.MOD POT : Adjust the amount of modulation applied.MODE SW: Toggle switch to switch modesOCT SW: Switch octave. Three ranges of -1, 0, +1.PUSH SW : Switch the tone. Eight tones can be selected in each mode.
MOD CV : Adjust the amount of modulation applied. The input range is 0-5V.V/oct : Control frequency. Input range is 0-5V, resolution is 10bit.OUT: Audio output, output range is 5Vp-p.
In Wavefold mode, it can also be used as a basic waveform VCO.In FM mode, you can get soft sounds and industrial waveforms with intense overtones.AM mode is intended for use with metallic percussion, and contains sounds that contain non-integer overtones.”