Heron’s Lights

Heron’s port and starboard hulls are equipped with red and green navigation lights. Under normal, autonomous operation these lights will be solid. These lights will flash to indicate certain high-priority states, such as a low-battery warning or a failure to communicate with the Heron’s base-station wireless network.

The table below shows animations of the LED patterns and their meanings.

Light Pattern	Description	Meaning
	Solid on	Robot is operating normally
	Solid off	Robot is powered-off, or operating normally with the lights turned off
	Fast double blink	Battery is low. Return to shore immediately to recharge
	Fast single blink	Robot is being driven manually via the remote control
	Slow single blink	Robot is idle, awaiting commands
	Slow triple blink	Failure to establish communication between the PC and MCU
	Slow double blink	Failure to communicate with the base-station, or no wireless network

During normal operation the lights can be turned-off by publishing to the disable_lights topic. This will suppress the lights during normal operation.