So I have previously designed up a
ESP32-C3 based SAO Controller board. This is nice and works well, BUT the MCU costs ￥23.7934 (around A$5.40) which is getting a bit pricey. I had volunteered to design up a Simple Add On (SAO) board for the 2024 KiCad Asia conference and run an assembly workshop around it.
- RP2040 SAO Controller-KiCon-Asia-2025.jpg (128.27 KiB) Viewed 728 times
So I thought it would be handy to try my hand at designing a SAO Badge/Controller based around something cheaper but still programmable using Arduino, so I selected the RP2040 MCU and designed up a simple PCB for it. The RP2040 MCU is less than a quarter of the price of a ESP32-C3 MCU.
- RP2040 SAO Controller.jpg (132.59 KiB) Viewed 728 times
Each KiCon participate received the red SAO Controller board and had a go at SMD assembling the blue SAO KiCon Asia board. When it's plugged into the controller, a RGB LED will shine through the PCB and a reverse mounted red LED shines through a hole in the board. The first thing the SAO Controller does as it powers up is to attempt to read the SAO boards 256 byte EEPROM to try and determine what kind of board it is. If it knows about it then it run run the relevant SAO boards code.
Thanks to NextPCB for sponsoring the PCB and assembly of the RP2040 SAO Controller boards and the SAO KiCon Asia board.
You can find all the relevant project open hardware and
example software here