Humidity sensor problem

[klausenlie]

Hi!

I am trying to calibrate the humidity sensor with the on board temp sensor which I bought from Hobby Boards but have some problems.

I read the VDD to 4,72 Volts and the Vout to 0,035 V having the sensor placed indoors.
I calculate the value to be 1,273.

When calculating like in the book by Tim Bitson to set the HUMIDITY_GAIN factor I calculate this factor to -0,05.

My sensor reads in the beginning - 24 or something like that.

When inserting my calculated value into the gain factor I get 1, 22% humidity.

Has something gone wrong with my sensor?

[tbitson]

Make sure the jumper JP1 is across pins 2 and 3 if you are using parasitic power. Measure the voltage on pin 2 to ground and make sure you have about 5 volts.

If you are using external power, the jumper needs to be across pins 1 and 2.

[klausenlie]

Hi Tim.

On my humidity board I only have two pins for the JP1 jumper.
In the book it says that the jumper should be removed when running in parasite mode.
How should I handle this?

[klausenlie]

From the spec the sensor shouldn`t be able to go as far down as 0.03 V or is there something I`m not thinking about.