ATtiny software PWM to drive RGB LED

Based on Atmel’s AVR136: Low-Jitter Multi-Channel Software PWM Application note, here’s a 3 channel software-based pulse width modulator to drive a RGB LED. This is a proof of concept and currently there is some in-efficient color cycling code in there, but the goal is to drive these cheap chips using an I2C (two wire serial) bus. Disco dance floor anyone?…