Write an esp32 Watchdog with Arduino

        I refer to a lot of online information about ESP32 Watchdog article , Many settings are incorrect , The watchdog doesn't work ! By accident Arduino In the sample program of the software, I turn to Watchdog routine , Take a look at working , See light suddenly , It turned out to be a timed interrupt ! Just interrupt the program to execute a reset instruction ! I went to , I used to know that the watchdog should be an independent hardware , You can only watch the door , I didn't think he could also be a timer !

        But the routine in the software is not enough to satisfy me , Simply make a watchdog package , Convenient for future use . The procedure is very simple , There are notes , You can see it at a glance . Post the code below , Welcome criticism and correction .

Module file :Watchdog.c

/*
 * ESP32 How to use the watchdog object :
 * 1、 Reference object definition file ( This document )：#include "Watchdog.C"
 * 2、 Declare the watchdog object variable ：WATCHDOG Watchdog;
 * 3、 Initialize object ：Watchdog.begin();// Timer is used by default 0,10 Second timeout .// It's fine too Watchdog.begin(1,1000);// Specify timer and timeout .
 * 4、 feed a dog ：Watchdog.feed();
 */
#ifndef ESP_RT_WDT_H  // Avoid repeating definitions .
  #define ESP_RT_WDT_H  
  #include "esp_system.h"
  class WATCHDOG {
    private:
      hw_timer_t *timer = NULL;// Timer Objects .
      uint8_t Timerindex=0;// Hardware timer number . Default timer 0.
      uint16_t Timeout=10000;// Timer count . Default 10 Second timeout .
    protected:
      static void Callback(){
        // Timer overflow callback function , Direct reset .
        esp_restart();
      }
      void Init(){
        if(timer!=NULL){timerEnd(timer);}// If the timer has been set before , Then turn off the corresponding timer .
        timer=timerBegin(Timerindex,80,true);// Use hardware timer , prescale 80, Count up .
        timerAttachInterrupt(timer,Callback,true);// Set the callback function , Edge delay trigger .
        timerAlarmWrite(timer,Timeout*1000,true);// Set the interrupt counter value , Automatic restart count （ Cycle timing ）.CPU Main frequency 80MHz/80/1000=1 millisecond .
        timerAlarmEnable(timer);// Turn on timer .
      }
    public:
      WATCHDOG(){Timerindex=0;Timeout=10000;}
      void begin(){Init();}
      void begin(uint8_t Esp_Timerindex,uint16_t Esp_Timerout){Timerindex=Esp_Timerindex,Timeout=Esp_Timerout;begin();}
      void feed(void){timerWrite(timer,0);}// feed a dog .
  };
#endif

Validation program file Watchdog.ino

#include "Watchdog.C"
uint8_t button=0;// Key IO--D0(GPIO0)
WATCHDOG Watchdog;// Watchdog object .
void setup() {
  Serial.begin(115200);// Serial port baud rate .
  Serial.println(" System reset !");// Print start information , To indicate that the module has been reset .
  pinMode(button,INPUT_PULLUP);// Key IO The input mode .
  Watchdog.begin();// Default timer 0,10 Second timeout .
  //Watchdog.begin(1,1000);// Watchdog initialization , Use timer 1,1 Second timeout .
}

void loop() {
  Watchdog.feed();// feed a dog .
  long loopTime = millis();
  while (!digitalRead(button)) {;}// If the key exceeds the set time , Will be too late to feed the dog and overtime .
  loopTime=millis()-loopTime;
  if(loopTime>1){Serial.printf("\r\n Key time :%d millisecond .",loopTime);}// If the key does not time out, the time spent on pressing the key will be displayed .
}

If the key times out , Just restart it all ,