micro

Arduino pro micro programmed successfully about 7 years ago using version 1.8.19 of Arduino IDE. Today we tried using the version 2.3.6 and the IDE did not recognize the device.

SSD1306 128 * 32 i2c happily responds and is back in operation.
The board is recognized as 'Arduino Micro'. The silk screen shows 'Pro Micro'.

So an old version of the IDE did the job.

micro python
micropython

microbit
micro-bit-Go-Bundle

Specifications include:
32-bit ARM Cortex-M0 CPU
debug with OpenOCD