555 B
555 B
v2
same USB type-A plug form factor. change MCU to STM32F042 since it provides read out protection, can recover 48 MHz clock from USB, and is easy to solder.
v1
smaller form factor. fits in USB type-A port. uses CH32V203 as it is smaller, cheaper, and requires less external parts (DP pull-up, crystal).
issues:
- USB pins are mirrored
v0
this is a large development board. it accepts the classical STM32F103 (which I'm more familiar with), and CH32V203 (cheaper). it has a proper debug port and buttons.
issues:
- USB pins are mirrored