Arduino Leonardo/Micro As Game Controller/Joystick : 10 Steps - Instructables
Amazon.com: Pro Micro ATmega32U4 5V 16MHz Micro-USB Development Module Board with 2 Row pin Header Compatible ard-uino Leonardo Replace ATmega328 Pro Mini : Electronics
10PCS/LOT New Pro Micro for arduino ATmega32U4 5V/16MHz Module with 2 row pin header For Leonardo - AliExpress
Arduino Leonardo Pro Micro Atmega32U4 5V/16Mhz Replace Pro Mini ATmega328 | eBay
Pro Micro & Fio V3 Hookup Guide - SparkFun Learn
Pro Micro 5v 16M Mini Leonardo ATMEGA32U4 Module Controller Board Replacement for Arduino Nano - AliExpress