Reset Retained Variables w/o power cycle

[rickkas7]

The idea is that you put all of your retained variables in a struct, like this:

rickkas7/google_cloud_tutorial/blob/master/1-electron.cpp#L24

There’s only one member, deviceName, but you’d add all of your retained values after that if you had more.

The magic value itself is 0xa2c7206a, which I generated randomly.

A setup or some similar time, you check if the magic is valid, and if not, reinitialize all of your values.

		if (retainedData.magic != RETAINED_DATA_MAGIC || retainedData.deviceName[0] == 0) {
			memset(&retainedData, 0, sizeof(retainedData));
			retainedData.magic = RETAINED_DATA_MAGIC;

			Particle.subscribe("spark/", deviceNameHandler);
			Particle.publish("spark/device/name");
			state = NAME_WAIT_STATE;
			stateTime = millis();
		}