wdt.h is included on Arduino IDE. This example show how it's work: #include <avr/wdt.h> int counter=0; void setup(){ wdt_disable(); Serial.begin(9600); Serial.println("Starting..."); delay(1000); wdt_enable(WDTO_8S); } void loop(){ wdt_reset(); Serial.println(counter); counter++; if(counter==5){ while(true){} } delay(500); }```

@dzairo search the Web for rebooting arduino from code. There are many ways each with its own (dis) advantages.

@NeverDie All I can say is that after adding the watchdog I have not had a lockup in 2+ months. Before that, like you, I had random lockups. Based on this positive experience I also added a watchdog to the one repeater I have in my system. Had a brief power outage the other day and everything came back online by itself with no problems.

yeah , I will test it .. thanks . If button change then send packet with ACK , and wait .. if not ack received then error .. rebards