a single sensor mounted on a bed support beam
As part of a sleep phase monitoring alarm clock, i was looking at different ways to track my movement during the night. The sensor i finally settled on, was a homebuilt pressure sensor made from aluminium / tin foil, an anti-static bag and foam rubber. There are similiar sensors already described on various pages. However these are either rigid (using copper board) or use conductive fabric, which can be hard to find. The nice thing about this sensor is, that it is rather flexible, thin and has a wide range of resistance. Distadvantages are the large drift over time and variance between different sensors. (more…)
