Developer Builds Observability Layer for Home Robotics Arm Using CAN Bus Telemetry

A developer building a home robotic arm created a lightweight telemetry system called 'sentinel' to monitor hardware health in real time without disrupting the control loop. The system passively listens to the robot's CAN bus, which broadcasts motor status frames carrying position, velocity, torque, and temperature data at roughly 600 frames per second. Written in Rust and running on a Raspberry Pi, sentinel samples 10 frames per second per motor and batches the data via HTTP POST to an external API. The system is designed to be best-effort, discarding samples and logging loss counts rather than queuing indefinitely, ensuring it never destabilizes the machine it monitors. A 40-minute offline test confirmed the loss accounting was accurate, validating the approach as a foundation for a broader 'physical API' layer for the robot.