Barometer Calibration

[sgtbean]

OK, so I got the HB barometer and had it calibrated by the vendor. Hooking it up though, it displayed an almost constant 28.39 inHg, while three local weather stations (same altitude, about 2 miles from me) say it should be 29.76 (!).

After letting it sit for a day or so, it still gives me this huge offset and nothing changed. Now I want to check the voltages are correct, but I could not use the OneWireViewer for this as it could not detect the TEMP08 that I use to interface with the sensors. Is there a way to read the voltage using a multimeter directly on the board? Which pins should I use to get the correct voltage?

 

[ericvic]

You can measure the voltage between GND and pin2 of JP1. Then you can perform the calibration as described on the website.

Eric

 

[sgtbean]

Yes!! I'm up and running, just gonna monitor the values for a day or so to see if I need to tweak it a hear left or right. Good stuff!!

Thanks Eric!!

 

[chubbard]

OK, I know this is an older post but I have just purchased the barometer. I cannot seem to find the calibration routine on the hobby boards website. I know the algorithm to determine barometric pressure but I have no slope or intercept (offset & gain) values. Wasn't there a webpage that calculated that info on the hobby boards website? I write my weather stuff in C but I found the Weather Toys java code and just port the code over to C.
 
I wrote to hobby boards support but never got a response. That disappoints me.
 
Thanks for any help.

 

[ericvic]

We used to have a Barometer Calibration Calculator page on the website but I guess it didn't make the move to the new site.
 
Send an email to [email protected] with your altitude and email address and I will run the calculator and email you the results.
 
Eric