An industrial-style SCADA master-slave network over RS485, with EEPROM-backed historical logging surviving power loss.
A smart-home monitoring and control system built to industrial SCADA conventions rather than a typical hobbyist IoT project: a laptop acts as the supervisory master station, and an embedded remote terminal unit handles sensing, relay actuation, and persistent logging — communicating over long-range RS485 with a custom command-response protocol.
Master-slave topology over UART/RS485. The master issues structured commands; the RTU firmware parses, validates and responds, while independently polling sensors and managing EEPROM-backed historical state.
RS485 half-duplex communication is prone to timing and collision issues absent from simple point-to-point UART links.
Implemented structured packet framing and validation so the RTU could reliably distinguish valid commands from line noise.
Logging needed to survive power cycles without wearing out EEPROM through excessive write cycles.
Logged only max/min/latest values rather than continuous history, minimizing write frequency while preserving the data that matters.
The system reliably performs long-distance bidirectional communication, real-time monitoring and remote actuation, with historical readings intact across power interruptions — mirroring the reliability expectations of real industrial SCADA deployments.