Baro sensor calibration

[philplane]

I'm trying to calibrate my baro sensor, but I'm not getting sensible readings.

I've used the baro calc page to get the offset voltage (1400ft, 3.359v). I've set the jumper to 1-2 and fiddled with the pot till the voltage is correct.

When I read the sensor it returns 29inHg (981.2hPa) in calibration mode. I put the jumper to 2-3 and it returns 4.77volts which I convert to 1015.4hPa. The actual pressure is approx 1005hPa, so I'm way out.

My software assumes to sensor voltage returned is linear from 2v to 7.759v, (28inHg to 32inHg).

Any advise?

--
Philip Plane

 

[ericvic]

Philip,

You may need to tweak the calibration pot a bit to get the readings as close as you can. THen you may need to apply a small offset in your software.

Eric