It should be bridged for 5V Pro Micro. Without the solder bridge cheap Pro Micro spit out only 4.6V instead of 5V at both VCC and RAW pin in my test. This is due to forward voltage drop of protection ...

Turns the ultimarc spintrak spinners into either USB mouse x-axis mode or left-stick-x-axis mode, using an Arduino Pro Micro. The arduino also works as an arcade button+stick encoder as well. Giving ...