It is not pure Lego: infrared filters from an old TV remote have been lightly hot-glued over the two standard NXT Light Sensors. A fruit jar lid with a wet sponge insert has been hot-glued to a small Lego part; this allows the flipper arm to bring the sponge over on top of the candle.
The port and starboard NXT Touch Sensors are multiplexed with a Mindsensors unit which then allows a free sensor port for the NXT Sonar Sensor.
A skeleton program is sort of working; it can feel its way through a maze, detect a flame, move up to the flame, and bring the sponge down on it. It doesn't succeed all of the time (hardly ever!) so I've still got a lot of programming to do.
