Uploading the miniAtmegatron to your Arduino Uno is very simple and takes a matter of minutes, once all the software is downloaded and installed. Just follow these easy steps. There is also a Tutorial Video that goes through the process.

Issue 2 and 3 kits have different LED pinouts and require a slightly different version of the software to correct this. The issue number of the PCB is shown just below the value increment button on the PCB.

STEP 1 – Install the header

Disassemble the case if present. Remove the shield. Insert the header in position shown (also shown in manual). Replace the shield.

arduino header

STEP 2 – Install the Arduino software

Download and install the latest Arduino IDE for your operating system. Be sure that USB drivers is checked when installing. Then connect the Arduino Uno + shield to a USB port. Some drivers may be installed.


STEP 3 – Install Easy Uploader

The Easy Uploader is the app used to upload software to the Atmegatron. Download the appropriate file and install.

Easy Uploader v1.1 for OSX (10.9 and above)
Easy Uploader v1.1 for Windows (WinXP and above 32 and 64 bit)

Once installed, run the app (making sure the programmer cable is already connected. Once the software has booted, select the COMM Port of the programmer cable from the combo box. It is often the bottom option.

easy uploader

STEP 4 – Upload the software

Click the Upload… button. Select the .hex file which you wish to install. The .hex files are available below. The software takes 20-30 seconds to upload. Once completed if you wish to use MIDI, you will need to disconnect the miniAtmegatron, remove shield, remove the header and then reassemble.

If you have any issue uploading software, please check the “show console” box, then copy and paste the text in the console window to a new thread on the Soulsby Synths forums.

miniAtmegatron Software


miniAtmegatron v3.1 for issue 2 PCBs
miniAtmegatron v3.1 for issue 3 PCBs

This is the latest version of the standard miniAtmegatron software. Kits shipped prior to May 2017 will be proloaded with v2.2 or earlier. Updates include patch initialise, pattern transpose via MIDI and all parameters controllable via MIDI CCs. See the manual for info.

miniAtmegatron Manual v3.0

Lemur templates:

mini lemur miniAtmegatron iPhone 5/s
miniAtmegatron Android Nexus
miniAtmegatron iPad Pro
miniAtmegatron Android Lenovo

TouchOSC template:

miniAtmegatron iPad

Ctrlr template:

miniAtmegatron Ctrlr


miniOdytron v1.1 for issue 2 PCBs
miniOdytron v1.1 for issue 3 PCBs

Analogue Modelling synthesizer. Get the spec of a classic analogue synth, but in an 8-bit environment! This is a port of the Odytron audio engine to the miniAtmegatron. It A large range of parameters are available. Full details are in the manual.

miniOdytron Manual v1.0

Lemur templates:

ody lemur
miniOdytron iPhone 5/s
miniOdytron Android Nexus
miniOdytron iPad Pro
miniOdytron Android Lenovo

TouchOSC template:

miniOdytron iPad

Ctrlr template:

miniOdytron Ctrlr


This is the assembly instructions that ship with the miniAtmegatron.

Assembly Instructions
Operation Instructions

Arduino MIDI-hack


Tutorial on MIDI-hack process
Atmel Flip 3.4.7 for Windows


It is possible MIDI hack the Arduino Uno using a Mac, but it is trickier than on a PC and involves using Terminal. Soulsby Synths does not provide support for this, however you can find more information about the process here and here.

Arduino MIDI firmware

All credit to MORECAT_LAB for the firmware.

Midi Firmware for Arduino Uno (Moco)

Miscellaneous files

miniAtmegatron Manual V1-0
miniAtmegatron schematic
miniAtmegatron board layout
miniAtmegatron case assembly tips
Reaper plugin using MIDI CCs for v1.0-v2.2
Reason Combinator backdrops

Thanks to…

Thilo Goldschmitz – Reaper Plugin. Richard Hider – TouchOSC templates and combinator backdrops. Jörg Boller – Ctrlr templates. Roland Nebe – Android Lemur templates.