Watchdog reset recovery in Embedded C

Introduction

A watchdog timer helps your device restart if it gets stuck. Watchdog reset recovery means your program notices this restart and fixes things to keep running smoothly.

When your device might freeze and you want it to restart automatically.

When you want to check if the last restart was caused by the watchdog timer.

When you want to clear error states after a watchdog reset.

When you want to log or handle watchdog resets differently from normal resets.

Syntax

Embedded C

if (WDT_ResetFlag()) {
    // Handle watchdog reset recovery
    Clear_WDT_ResetFlag();
    // Your recovery code here
}

WDT_ResetFlag() is a placeholder for your microcontroller's way to check if a watchdog reset happened.

Always clear the watchdog reset flag after detecting it to avoid repeated recovery actions.

Examples

This example resets error counters after a watchdog reset.

Embedded C

if (WDT_ResetFlag()) {
    // Restart watchdog timer
    Clear_WDT_ResetFlag();
    // Reset error counters
    error_count = 0;
}

This example logs a message when a watchdog reset happens.

Embedded C

if (WDT_ResetFlag()) {
    Clear_WDT_ResetFlag();
    Log("Watchdog reset detected");
}

Sample Program

This program simulates checking for a watchdog reset. If detected, it prints messages and clears the flag to recover.

Embedded C

#include <stdio.h>
#include <stdbool.h>

// Simulated watchdog reset flag
static bool watchdog_reset_flag = true;

// Function to check watchdog reset flag
bool WDT_ResetFlag() {
    return watchdog_reset_flag;
}

// Function to clear watchdog reset flag
void Clear_WDT_ResetFlag() {
    watchdog_reset_flag = false;
}

int main() {
    if (WDT_ResetFlag()) {
        printf("Watchdog reset detected. Recovering...\n");
        Clear_WDT_ResetFlag();
        // Recovery actions here
        printf("Recovery complete.\n");
    } else {
        printf("Normal startup.\n");
    }
    return 0;
}

Important Notes

Different microcontrollers have different ways to check and clear watchdog reset flags. Check your device's manual.

Always clear the watchdog reset flag early in your program to avoid repeated recovery loops.

Summary

Watchdog reset recovery helps your program handle automatic restarts caused by watchdog timers.

Check the watchdog reset flag at startup to know if a reset happened.

Clear the flag and perform recovery actions to keep your device running smoothly.