The miniAtmegatron is a DIY shield kit that will turn your Arduino Uno into an 8-bit synthesizer.
Back in 2014, Soulsby had introduced an 8-bit synth called Atmegatron which combined the sounds of 1980s home computers with the flexibility and power of a modern-day synthesizer. Now, its creators have relaunched a new and improved version of their sound MIDI machine along with an Arduino Uno shield kit, the miniAtmegatron.
Key features of the ATmega328P powered Atmegatron include 32 waveforms, 15 digital filter types, two ADSR envelopes, one LFO with 16 waveforms, an arpeggiator with 15 patterns and loads of FX including phaser, distortion and Wavecrusher. The gadget comes pre-loaded with 16 preset sounds — ranging from bass to chiptunes — and unlimited expandability via the Atmegatron Librarian software (Mac or PC), which enables it to shape-shift between a drum machine, a duophonic synth and a delay synth.
There are two ways to edit and manage the sounds: six knobs on top along with a value and function knob on the bottom. Turning the left-hand dial selects the parameter to concentrate on, while its value is updated by turning the right. Audio is generated by modulating a PWM output of its built-in AVR processor and filtering off the modulation frequency. The Atmegatron employs analog circuitry in the form of a steep third order Chebyshev filter to maintain the high end, while still filtering off the modulation frequency.
Meanwhile, the Atmegatron’s software utilizes two loops to create its unique tunes. One loop leverages an interrupt to update the PWM output at audio frequencies, with the slower, second loop tasked with the remaining functions (MIDI input, process the wavetable, update LFOs, envelopes, arpeggiators, etc). As expected, the synthesis engine can be completely altered and modded by uploading software to the sleek-looking synth.
What’s more, Soulsby has unveiled the miniAtmegatron, a synthesizer shield kit for the highly-popular Arduino Uno platform. Based on the sound engine of the Atmegatron, the DIY set is comprised of a PCB, all of the necessary electronic components and an instruction manual. It should also noted that the build time will vary (from 30 minutes to an hour) depending on a user’s soldering experience.
The shield is attached to the Arduino and the source code is easily uploaded. Aside from that, the miniAtmegatron features a 3.5mm audio jack for headphones and two LEDs (left shows function, right indicates value) which are controlled by four buttons. Similar to its older sibling, the device boasts a wide range of capabilities. These include a pattern generator, 16 wavetables, 15 digital filter types, two preset envelopes, 16 LFO shapes and speeds, and FX like Wavecrusher and Portamento. Six on-board knobs can be employed to adjust 12 different parameters, such as filter cutoff, distortion, resonance and pitch. The miniAtmegatron can be even be converted into a MIDI instrument by hacking your Arduino Uno, then played via USB.
Sound like something you’d love to play with? Head over to the Atmegatron and miniAtmegatron’s official page here.