Watchdog Timer

Watchdog Timer

Example: Task Watchdog Timer (TWDT)

In this example, the watchdog timer is set with an overflow time of 3 seconds. For the first 10 seconds, the watchdog is reset every 2 seconds. After 10 seconds, the watchdog is no longer reset, causing the watchdog timer to overflow and the board to reset.

Hardware Required:

• ESP32 IoT Programmable Controller (SKU: DFR0886)×1

Example Code:

#include <esp_task_wdt.h>

// 3-second Watchdog Timer (WDT)
#define WDT_TIMEOUT 3

void setup() {
  Serial.begin(115200);
  Serial.println("Configuring WDT...");
  esp_task_wdt_init(WDT_TIMEOUT, true); // Enable panic, ESP32 auto-restarts on WDT timeout
  esp_task_wdt_add(NULL); // Add the current thread to WDT monitoring
}

int i = 0;         // WDT reset counter
int last = millis(); // Record last reset time

void loop() {
  // Reset WDT every 2 seconds, stop after 5 resets
  if (millis() - last >= 2000 && i < 5) {
      Serial.println("Resetting WDT...");
      esp_task_wdt_reset(); // Reset watchdog timer
      last = millis();      // Update reset time
      i++;                  // Increment counter

      // Stop resetting after the 5th reset, wait for WDT timeout and reboot
      if (i == 5) {
        Serial.println("Stopping WDT reset, CPU will reboot in 3 seconds");
      }
  }
}