I am an Atmospheric Science student at the University of Nevada in Reno, Nevada. Our professor purchased the Arduino boards and a set of SCP1000 chips equipped with the barometric pressure/temperature sensor.
We successfully wired the chip to the Arduino board and are attempting to run the "BarometricPressureSensor" example sketch for use in a project. After successfully uploading the sketch to the Arduino board, we are having trouble interpreting the results:
=26.6511111 1111100
100000 10000000
Pressure [Pa]=3690
100001 10000100
Temp[C]=26.5511111 1111100
100000 10000000
Pressure [Pa]=3677
100001 10000100
Temp[C]=26.6011111 1111100
100000 10000000
Pressure [Pa]=3663
The pressure, in Pascals, in Reno, Nevada should be about 850 millibars, or approximately 85 000 Pascals.
At first, we thought the sensor onboard the SCP1000 might be faulty, so we tried another sensor on another Arduino board and are getting the same values.
If you could provide some insight into the SCP1000 and this issue, it would be greatly appreciated.
Thank you,
Nic Beres
My SCP1000 works fine (incredibly sensitive, can 'measure' altitude to 20cm or something like that) - you need to show us the code to work out what's going wrong.
Looks like they have similar specs but the Bosch one is a lot quicker? Confused for a while with the Bosch datasheet using hPa as the unit of pressure - what? 0.01hPa = 1Pa (crazy Bosch engineers!) The SCP100 takes 0.75s for high-accuracy conversion I think, BMP085 is 25.5ms. For your bandwidth it might be better to have higher speed device or you'll be hitting the Shannon limit.
There is a problem with the sample sketch in that the binary shifts do not work in some places. Replace wherever it says "<< n" where n is an integer with *(2^n) where you have precalculated 2 to the n.
Yes, it's something like that. I can't remember the modifications I made, but the << 16 for the pressure definitely didn't work. I think I ended up using a 'long' for pressure. Try that. I'm also in the middle of writing a library for the SCP1000, so if you want I can make it available to you when finished.