Sensor reads only 0

[martiesim]

The original ikea board doesn't let the fan spin all the time, while the hack does, but slower.

After some time I noticed the sensors readings dropping to 0 and staying there. I suspected that the constantly spinning fan might be the cause and disconnected it. The readings started to rise again until they reached a plausible level.

I suspect the ikea board stops the fan for the sensor to have a chance get a reading. I read in some review of the sensor that it only needs the fan for the readings to not drift upward over (longer periods of) time. The reviewer mentioned it as a positive that ikea even bothered putting it in.

The solution to the problem for me was to keep the ikea boards controll over the fan intact. To get it to be quieter I cut the fans red (+) wire and soldered a 33 ohm resistor into it.

(Of course to have the ikea board control the fan, you should not cut the ICs pin 5, or reconnect it if possible if you already did)

I hope this is helpful for someone :)