Synthesizers you can make
All my Nixie clocks are controlled by a little microchip called an Mega AT328P which a lot of people know as the brain in the Arduino Nano / UNO controllers.
As well as telling Nixie tubes how to be a clock, they can also make sounds:
The original Arduino Nano can read 8 control knobs on it's analogue ports A0 - A7, you will find several programs and sketches out there that use this method. A good example would be the Helios Synthesizer that is basically an Arduino Nano and a lot of switches - Helios Synthesizer courtesy of Gary at Blog Hoskins. However you soon run out of analogue ports for control knobs, so my board doubles this up to 16 knobs by using some multiplexer IC's, and then gives you 5 control switches, a Midi input socket and a trigger in. You can also, depending on how you assemble the board omit the multiplexers and have 8 of the control knobs just connect directly to the Arduino.
I designed the board in KiCad, and you can download the schematic file here KiCad .sch file and the Pcb file here KiCad .pcb file and the netlist KiCad .net file or of course, the schematic as a .png should be somewhere below, or you can download here Schematic
I found all the code freely available online, so thank you folks for sharing it! I've just ammended the code to work with the multiplexing hardware and to use the #HIFI audio output option, and reposted it here.
As I develop things, more sketches will appear here - and any sent it will get added.
22/7/22 - 5 note polyphony now possible! Use this Sketch: Poly Synth Sketch Download and install in the Synth and start playing
Many thanks to Tim Barrass https://sensorium.github.io/Mozzi/ for creating the Mozzi library that allows the Arduino to make all these noises!
The Hardware uses the #HiFi audio out as defined in the mozzi.config file, so don't forget to enable this otherwise the sketches will not work!
Also if required, I can provide you with a blank PCB at cost, or a complete built up unit for you to play with - contact me for details.