We propose to non-invasively monitor the status of the Mary Lyons laundry machines. We will design and produce a sensor to detect the activation of the machines and will present activation events (and the derived time-to-finish information) on a web site.
The proposed sensor, (available from its TinyCAD design file) senses the light of the laundry machine's LEDs, and replicates this information with a new LED and as a TTL-compatible logic signal, to be read on a computer's parallel port. The circuits will be powered off of the computer's USB port. The sensor's schematic is given below: