watchdog test (not working for now)

arduino_nano/main.c

@@ -40,6 +40,7 @@
 /* variables */
 bool query_pzem004 = false; // flag to query the PZEM-004 power meter
 volatile uint8_t timer_seconds = 0; // how many seconds have passed
+volatile bool watchdog = true; // set when watchdog interrupt occurred
 
 /* disable watchdog when booting */
 void wdt_init(void) __attribute__((naked)) __attribute__((section(".init3")));
@@ -74,7 +75,7 @@ int main(void)
 {
 	io_init(); // initialize IOs
 	
-	//printf(PSTR("welcome to the spar counter power meter monitor\n"));
+	printf(PSTR("welcome to the spar counter power meter monitor\n"));
 	
 	struct configuration conf; // node configuration
 	// read configuration data from EEPROM + CRC-8-iButton value
@@ -109,8 +110,24 @@ int main(void)
 	bool send_values = false; // set to true to send out the values
 	
 	bool action = false; // to know if we performed any king of action during which some other activity could have happened
+
+	/* start watchdog */
+	wdt_enable(WDTO_4S);
+	while (true);
+	WDTCSR = (1<<WDCE); // change settings
+	//WDTCSR = (0<<WDP3)|(1<<WDP2)|(1<<WDP1)|(1<<WDP0); // set time-out to 2s
+	WDTCSR = (1<<WDP3)|(0<<WDP2)|(0<<WDP1)|(1<<WDP0);
+	WDTCSR = (1<<WDCE); // change settings
+	WDTCSR = (1<<WDE)|(1<<WDIE); // enable interrupt than system reset mode
+	while (true);
+
 	while (true) { // endless loop for micro-controller
 		action = false; // new cycle of actions
+		if (watchdog) { // watchdog interrupt trigger. clear before system reset
+			WDTCSR = (1<<WDCE); // change settings
+			WDTCSR = (1<<WDE)|(1<<WDIE); // enable interrupt than system reset mode
+			watchdog = false;
+		}
 		if (timer_seconds!=0 && timer_seconds==conf.request_period) {
 			action = true; // an action is performed
 			timer_seconds = 0; // restart timer
@@ -247,3 +264,9 @@ ISR(TIMER1_COMPA_vect)
 {
 	timer_seconds++; // count seconds
 }
+
+/* watchdog interrupt */
+ISR(WDT_vect)
+{
+	watchdog = true;
+}