WatchDogTimer

離れたところにマイコンをセットするとフリーズしたらもう終わりなので、ウォッチドッグを仕掛けた。
サンプルlibraries/ESP32/examples/Timer/WatchdogTimer/WatchdogTimer.ino

＃include "esp_system.h"

const int button = 0; //gpio to use to trigger delay
const int wdtTimeout = 3000; //time in ms to trigger the watchdog
hw_timer_t *timer = NULL;

void ARDUINO_ISR_ATTR resetModule() {
ets_printf("reboot ");
esp_restart();
}

void setup() {
Serial.begin(115200);
Serial.println();
Serial.println("running setup");

pinMode(button, INPUT_PULLUP); //init control pin
timer = timerBegin(0, 80, true); //timer 0, div 80
timerAttachInterrupt(timer, &resetModule, true); //attach callback
timerAlarmWrite(timer, wdtTimeout * 1000, false); //set time in us
timerAlarmEnable(timer); //enable interrupt
}

void loop() {
Serial.println("running main loop");

timerWrite(timer, 0); //reset timer (feed watchdog)
long loopTime = millis();
//while button is pressed, delay up to 3 seconds to trigger the timer
while (!digitalRead(button)) {
Serial.println("button pressed");
delay(500);
}
delay(1000); //simulate work
loopTime = millis() - loopTime;

Serial.print("loop time is = ");
Serial.println(loopTime); //should be under 3000
}