The Wee O3

An ionized O2 MiniPop

The Wee O3 is an Arduino Nano based emulation of a Korg Mini Pops drum machine.
The O3 follows Jan Ostman's O2 from 2016 with additional features and optimizations for the Korg SQ-1 sequencer.
Video with feature demonstration
In addition to the standard 16 drum patterns and 8 samples the following features are provided:

New Features

• Analog pitch control via potentiometer or CV input. Changing the pitch will change the tempo as well because pitch control is achieved by changing the interrupt timing.
• Combined CV / potentiometer input for selecting a sample (rising edge) and triggering it (falling edge). Compatible with the littleBits OUT of the Korg SQ-1 sequencer.
• Manual S Trigger input for triggering the selected sample.
• Bi directional clocking: Turning tempo all the way down disables internal clock and switches system to clock input.
• CV input for tempo control.
• CV input for drum pattern selection.
• Double functionality for A0-A3: Sequence counter when running, pattern number when stopped. LEDs or a display connected to these pins make pattern selection easier.

Hardware

While the schematics in this repo provide full functionality, the circuit can be easily reduced and optimized.

Credits

Thanks to Jan Ostman for the original code and design.

Enjoy - and get into the O Zone !