Atmegatron Complete


The Atmegatron is a revolutionary synthesizer that takes classic 80s Chiptune sounds and adds powerful new features.
Musicians will love it because it is quick and easy to create and manipulate amazing sounds. The Atmegatron can do everything from bright square wave leads, to dirty basses, to wild sci-fi effects.
Programmers will love it because it is built on the Arduino platform and the software is open source. This allows programmers to change or add new features and upload them to the Atmegatron.



  • 8-bit monophonic MIDI synthesizer
  • Unique Wavetable PWM Synthesis audio engine.
  • Quick and intuitive controls, no complex menu systems
  • Stylish white aluminium case with walnut side panels
  • Many features controllable by MIDI:
    mod & pitch wheels, filters, portamento and more
  • 16 preset sounds that can be overwritten with your own patches


  • Huge selection of waveforms and filters
  • Upload your own waveforms using the included Atmegatron Librarian software
  • LFO and 2 envelopes
  • Powerful synthesis features that takes Chiptune beyond 80s computer sounds
  • Advanced arpeggiator sequencer
  • Unique ‘wave crusher’ effect
  • Analogue bass boost for warm bass sounds


  • Download the open source code from the downloads page
  • Download the free Arduino development environment
  • Tutorials and forums to help programmers
  • Upload software using FTDI cable


32 waveforms LFO with 16 waveforms MIDI clock sync
15 digital filter algorithms Filter and pitch envelope modulation Analogue bass boost circuit
2 ADSR Envelopes Pitch and phase LFO modulation Wave crusher
16 memory patches Filter, amplitude and pulse width LFO modulation Phaser
Portamento Arpeggiator with 15 sequences Distortion
Inputs/Outputs Extras
1/4″ mono jack 12V power supply
3.5mm stereo headphones 32 page colour instruction manual
MIDI input and output Quick reference card
12V DC power supply Free Atmegatron Librarian software available
6 pin header for programmer cable

Synthesis Engine

The Atmegatron uses the Atmel 328P processor, which is also at the heart of most Arduino development boards. Audio is generated by modulating a PWM output of the processor and then filtering off the modulation frequency. The Atmegatron uses analogue circuitry in the form of a steep 3rd order Chebyshev filter to maintain the high end, while still filtering off the modulation frequency.
The Atmegtron’s software uses 2 loops to create it’s unique sound. One loop uses an interrupt to update the PWM output at audio frequencies. The other loop is slower and is used for everything else (MIDI input, process the wavetable, update LFOs, envelopes, arpeggiators etc). This unique synthesis method means that while the Atmegatron is clearly at home among classic Chiptune synthesizers, it also sounds highly individual.
The diagram below shows the wavetable processing chain. This is the structure of the Arduino code that is shipped in the Atmegatron, but this can be tweaked as much as the user desires and reuploaded using the Arduino development environment.

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