LED Signals

We only have one LED, but we can signal quite a lot with it. Here is a list of signals and their meaning:

Signal	Meaning
LED blinks every second	Normal operation, battery voltage is above warn voltage
LED blinks every 2 seconds	Battery voltage is below warn voltage, RPI has been given the signal to shut down
LED blinks arhythmic	The Raspberry accesses the ATTiny via I2C, each read or write is one LED flash (happens once every sleeptime seconds)
LED blinks normally, then turns off after timeout	primed is not set and/or the daemon is not installed on the RPI
LED does not blink during normal operation	primed is 0 or system is in shutdown
LED blinks once when turned on	primed is 0 or system is in shutdown
LED blinks 5 times in fast succession	RPi should take action, possibly shut down
LED blinks 10 times in very fast succession	RPi has not accessed the I2C interface for more than "timeout" seconds. System is restarted
LED blinks 5 times in slow succession	RPi has not accessed the I2C interface for more thant "timeout" seconds, but a restart has already been tried without success. Nothing will be done
LED sends SOS	wrong fuse settings