Two TM4C123GXL boards transmit UART text over infrared by modulating the data onto a 38 kHz PWM carrier for a TSOP134 IR receiver. Uses simple logic gating + a transistor driver to send, receive, and print messages back to a PC terminal.

Six microcontroller projects on the ATmega2560: a custom Arduino-Mega-class PCB with production Gerbers, a bare-metal 40 kHz ADC sampler, a hand-built IR link-layer protocol, a timer-interrupt music game, a melody player, and a self-balancing-robot validation suite.

IR communication library for Mbed OS

Arduino and Raspberry PI communication through IR (Serial, NEC).