Update RelaySwitch.ino

Author: shramik49

examples/Actuators/RelaySwitch/RelaySwitch.ino

@@ -49,4 +49,13 @@ CAYENNE_IN(VIRTUAL_CHANNEL)
 	else {
 		digitalWrite(ACTUATOR_PIN, LOW);
 	}
-}
+}
+
+// This function is called at intervals to send data to Cayenne and keep the device online.
+// Will create a temporary green widget on Channel 0, make it permanent by clicking on '+'. 
+CAYENNE_OUT(0)
+{
+	CAYENNE_LOG("Send data for Virtual Channel 0");
+	// This command writes the device's uptime in seconds to the Virtual Channel. 
+	Cayenne.virtualWrite(0, millis() / 1000);
+}