When synthesizers first hit the scene again within the mid-Twentieth century, many had been monophonic devices, able to producing only one pitch at a time. This was a significant limitation, and over time polyphonic synthesizers started to flood into the scene, enormously increasing efficiency prospects. [Kevin] determined to construct his personal polyphonic synthesizer, but far from taking the easy route, he built it around the Arduino Uno – not a platform particularly well known for its musical abilities!
[Kevin]’s construct manages 12-note polyphony, a powerful feat for the ATmega328 on the coronary heart of the Arduino Uno. It’s accomplished by operating an interrupt on a timer at a gentle price, and implementing 12 counters, one per observe. When a counter overflows, a digital IO pin is flipped. This outputs a sq. wave at a sure pitch on the IO pin, producing the given observe. The outputs of 12 digital IO pins are blended along with a easy resistor association, producing a primary sq. wave synth. Tuning isn’t excellent, however [Kevin] notes just a few methods it could possibly be improved down the road.
[Kevin] has added options alongside the way in which, increasing the easy synth to work over several octaves via MIDI, while also building a small tactile button keyboard, too. It’s a undertaking that serves as an excellent gateway into primary synthesis and music electronics, and we’re positive [Kevin] realized lots alongside the way in which. We’ve seen different microcontroller synths earlier than too, like this tiny device that fits inside a MIDI plug. Video after the break.