Software for a Raspberry Pi which allows the monitoring of a boiler's hot water levels via a small web interface.
Requires a Raspberry Pi camera pointed at a boiler's 5-level red light (indicating the current temperature of the water), which it then uses to take a photo every minute to record the level vs time. This data can then be viewed using a web interface at the IP address of the Pi.
We used it because we wanted to see our boiler's timer function worked correctly because we were trying to save energy.