Everyone likes some free stuff once in a while. I have decided to release 3 recent PCB projects for free, no strings attached. The PCB’s include a STM32F103C8T6 ( BluePill ) in Arduino Uno Form Factor, as well as an additional two I2C IO Extender Shields, 8 DI and 8 DO, Both optically isolated, in a stack-able, addressable format.
Both I2C Shields are configured to use PB11 as SDA, PB10 as SCL and PB1 for interrupt.
All other “Blue Pill” Pins are broken out on Headers, completely pin for pin compatible.