Amazon.com: ATMEGA32U4 5V/16MHZ Module with The Bootloader for Arduino Mini USB/Micro USB with 2 Row Pin Header for Arduino (Micro USB 3-6V) : Electronics
Amazon.com: OSOYOO Pro Micro ATmega32U4 5V/16MHz Module Board with 2 Row pin Header Replace with ATmega328 Pro Mini for Arduino : Electronics
The ATmega328p microcontroller | Download Scientific Diagram