Watchdog for ESP8266 and ESP32

This post is a quick summary of using watchdog to help deal with unexpected hang / crash.

Arduino Sketch

Note, the code "watchdogCount = 0;" is commented out so the watchdog is triggered every 5 seconds.

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#include <Ticker.h> Ticker secondTick; int watchdogCount = 0; void ISRwatchdog() { watchdogCount++; if (watchdogCount == 5) { Serial.println(); Serial.println("The watchdog bites!!!"); ESP.reset(); } } void setup() { Serial.begin(115200); secondTick.attach(1, ISRwatchdog); } void loop() { Serial.printf("Watchdog counter= %d\n", watchdogCount); //watchdogCount = 0; delay(1000); }

The Result (watchdong not reset before it's triggered)

The Result (watchdog reset before it's triggered)

Reference:

HOW TO CREATE A WATCHDOG TO STABILIZE YOUR ESP8266
http://onlineshouter.com/how-to-create-a-watchdog-to-stabilise-your-esp8266/

ESP8266: Watchdog functions
https://techtutorialsx.com/2017/01/21/esp8266-watchdog-functions/