sl-firmware d41a9dfe10 feat(safety): remote e-stop over 4G MQTT (Issue #63)
STM32 firmware:
- safety.h/c: EstopSource enum, safety_remote_estop/clear/get/active()
  CDC 'E'=ESTOP_REMOTE, 'F'=ESTOP_CELLULAR_TIMEOUT, 'Z'=clear latch
- usbd_cdc_if: cdc_estop_request/cdc_estop_clear_request volatile flags
- status: status_update() +remote_estop param; both LEDs fast-blink 200ms
- main.c: immediate motor cutoff highest-priority; arming gated by
  !safety_remote_estop_active(); motor estop auto-clear gated; telemetry
  'es' field 0-4; status_update() updated to 5 args

Safety: IMMEDIATE motor cutoff, latched until explicit Z + DISARMED,
cannot re-arm via MQTT alone (requires RC arm hold). IWDG-safe.

Jetson bridge:
- remote_estop_node.py: paho-mqtt + pyserial, cellular watchdog 5s
- estop_params.yaml, remote_estop.launch.py
- setup.py / package.xml: register node + paho-mqtt dep
- docker-compose.yml: remote-estop service
- test_remote_estop.py: kill/clear/watchdog/latency unit tests

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-03-01 04:55:54 -05:00

66 lines
1.8 KiB
C

#ifndef SAFETY_H
#define SAFETY_H
#include <stdint.h>
#include <stdbool.h>
/*
* SaltyLab Safety Systems
*
* Covers:
* - IWDG hardware watchdog (MCU reset if main loop hangs)
* - RC signal timeout monitoring
* - Tilt fault alert via buzzer
* - Arm hold interlock (must hold arm for ARMING_HOLD_MS)
* - Remote e-stop over 4G MQTT (CDC 'E'/'F'/'Z' commands)
*/
typedef enum {
ESTOP_CLEAR = 0,
ESTOP_TILT = 1,
ESTOP_RC_KILL = 2,
ESTOP_REMOTE = 3,
ESTOP_CELLULAR_TIMEOUT = 4,
} EstopSource;
/*
* safety_init() — call once in main() after HAL_Init().
* Starts IWDG with WATCHDOG_TIMEOUT_MS timeout from config.h.
* Starts ARMING_HOLD_MS countdown from config.h.
*/
void safety_init(void);
/*
* safety_refresh() — call every main loop iteration.
* Resets IWDG counter. If not called within WATCHDOG_TIMEOUT_MS,
* the MCU will reset (independent of software — cannot be disabled).
*/
void safety_refresh(void);
/*
* safety_rc_alive() — returns true if RC receiver has sent a frame
* within RC_TIMEOUT_MS. Call from the balance loop.
*/
bool safety_rc_alive(uint32_t now);
/*
* safety_alert_tilt_fault() — one-shot buzzer beep for tilt fault.
* Safe to call repeatedly; only fires once per fault.
*/
void safety_alert_tilt_fault(bool faulted);
/*
* safety_arm_interlock() — returns true once arm button has been
* held for ARMING_HOLD_MS from the moment safety_arm_start() was called.
*/
void safety_arm_start(uint32_t now); /* Call when arm requested */
bool safety_arm_ready(uint32_t now); /* Poll until true, then arm */
void safety_arm_cancel(void); /* Cancel pending arm */
void safety_remote_estop(EstopSource src);
void safety_remote_estop_clear(void);
EstopSource safety_get_estop(void);
bool safety_remote_estop_active(void);
#endif /* SAFETY_H */