Secure & Safety-Critical Design
Once a device moves, radios, or stores data, "it works" is not enough. This subject is applying basic secure-coding and safety patterns on the device: input validation on serial/MQTT, no hardcoded secrets, watchdogs, and fail-safe actuator behaviour. Analysis of hazards belongs in Analysing & Advising; here you implement the mitigations.
Starting Points
- Safety & regulatory basics
- OWASP. Embedded Application Security (overview).
- IEC 61508 concepts at awareness level — Safety & constraints fundamentals.
Key Points
- You validate and bound external inputs (serial, radio, network) so garbage cannot command an actuator unbounded.
- You store credentials outside source control and rotate lab defaults.
- You implement a fail-safe (watchdog reset, motor disable on loss of heartbeat, e-stop input).
- You explain residual risk: what your design still cannot claim (SIL, CE, production hardening).
- You review a change for both safety and security impact before you merge it.