ESP32 Reboot system when watchdog timeout

Use for reboot when system obstructed.

Suggestion from https://github.com/me-no-dev

The story in https://github.com/espressif/arduino-esp32/issues/841

Following is working code.

#include "esp_system.h"
const int loopTimeCtl = 0;
hw_timer_t *timer = NULL;
void IRAM_ATTR resetModule(){
    ets_printf("reboot\n");
    esp_restart_noos();
}
void setup() {
    Serial.begin(115200);
    pinMode(loopTimeCtl, INPUT_PULLUP);
    delay(1000);
    Serial.println("running setup");
timer = timerBegin(0, 80, true); //timer 0, div 80
    timerAttachInterrupt(timer, &resetModule, true);
    timerAlarmWrite(timer, 3000000, false); //set time in us
    timerAlarmEnable(timer); //enable interrupt
}
void loop() {
    timerWrite(timer, 0); //reset timer (feed watchdog)
    long tme = millis();
    Serial.println("running mainloop");
    while(!digitalRead(loopTimeCtl)){
        Serial.println("button pressed");
        delay(500);
    }
    delay(1000);
    Serial.print("loop time is = ");
    tme = millis() - tme;
    Serial.println(tme);
}

Place code timerWrite(timer, 0); to feeding watchdog otherwise timeout fired and reboot.