Watchdog Configuration and Recovery
Configure watchdog coverage so a stalled critical path resets safely and records a useful cause.
Arduino-compatible frameworks, ESP-IDF/FreeRTOS, PIC/AVR/STM32/RP-class systems; apply exact vendor documentation for the selected MCU.Architecture
Task health votes → watchdog supervisor → hardware watchdog; reset reason retained for next boot.
Security and recovery risks
- Do not feed from an unconditional timer ISR.nDo not permanently disable watchdog to hide a fault.nAvoid reset loops with bounded recovery/fallback.
Implementation procedure
- List critical tasks and maximum healthy interval.nChoose watchdog timeout above proven worst-case latency.nFeed only after all required health votes.nInject a controlled deadlock.nVerify reset reason, safe outputs and recovery count.
Starter code / configuration
if (all_critical_tasks_healthy()) { feed_hardware_watchdog(); }Verification evidence
| Test | Expected | Evidence |
|---|---|---|
| Nominal boot | Correct version and hardware revision reported | Captured boot log |
| Fault recovery | Defined safe state and reset reason | Fault-injection record |
| Power cycle | No corrupt configuration or unsafe output | Repeated-cycle log |
Required release artifacts
- Versioned firmware binary and SHA-256
- Source revision / build identifier
- Board and hardware-revision compatibility list
- Test report and known limitations
- Recovery image and factory-reset procedure
- Provisioning/calibration schema
- Release approval record
Local browser tools
Firmware production workbench
A/B update exercise
OTA and automatic rollback simulator
Advance one validated stage at a time. A failed boot test returns the device to the previous slot.
- Running confirmed firmware from Slot A.
Release gate
Production-readiness checklist
A downloadable release decision is generated only after every mandatory control is confirmed.