Review on OSOYOO Pro Micro ATmega32U4 Module Board: 5V/16MHz, 2 Row Pin Header, Arduino Compatible – Upgraded Version with ATmega328 Pro Mini Support by John Eaton

Works great so far. Note that I've done a lot of things with Arduino on my computer before, so I might already have drivers that other people don't have installed. It appeared in the list already identified as Leonardo) Connect the LED to pin 9 and modify the sketch accordingly. Click "Download" and a few seconds later I had a blinking LED. Please note that for some reason the built in red Rx LED keeps blinking even after boot, not sure why. I unplugged it from my computer and plugged it into the battery I used to charge my phone on the go and it worked again with no issues and no flashing red light. So it seems to be getting some sort of continuous data signal when connected to my computer, which is odd but doesn't really seem to be a problem. The pinout appears to match the Sparkfun Pro micro board I've attached the diagram to. EDIT: I just realized that the pins with white circles are PWM pins.