Hello to everyone,
we are using Parallax PIR Sensors in a project for modelling room occupancy. We use them connected to a TelosB wireless sensor module: the output pin of the PIR sensor is connected to the TelosB ADC port, from where we got the readings of the output.
The problem is that, after the initial warm-up during which the output varies from 0 to around 1,4V, we have got an "always-high" reading. We don't think it is a software problem, since the readings slightly vary around 1,4V. Obviously we are very careful in avoiding any movement during the warm up, and even if we put the sensor in an empty room the results don't change.
Does anyone have any suggestion of what it may be? I searched a lot on this forums and on the web too, but I couldn't find any solution that works.