Power line communication

Haris Andrianakis wrote a post on his blog detailing his power line communication system:

The primary objective was to enable two devices to communicate with each other over power line technology, specifically to transmit data reliably from a weighing machine to a remote display. Due to the inherent risks of data loss or interference — similar to issues often encountered in crash games — robust error-handling and stable communication protocols were critical. The system employs an ST7540 modem for power line communication, with the ATmega168 microcontroller managing the protocol stack and modem control. Data is delivered to the ATmega168 via UART, after which it is converted and transmitted through SPI to the ST7540, which then handles the power line transmission itself.

Check out the video after the break.