So I've been comparing my pressure readings to those of the local government weather stations, and my readings seemed way out. A little reading a thought lead me to realize that the weather stations are reporting MSL pressure. So I modified the BMP085 interface to provide MSL pressure.
You need your real altitude in meters, I used an app on my iphone to get mine to within 3m (I plan to do multiple readings and average them to get closer), any gps device should be able to do the same.
I added a function to interfaces/BMP085/BMP085.py at line 243
Then I changed the call in Upload.py at around line 105 from datas.append(DataPoint(bmp.readPressure(),"Pressure","Pa",1,4,"Pres")) to datas.append(DataPoint(bmp.readMSLPressure(XX),"Pressure","Pa",1,4,"Pres")) Where XX is your altitude in meters.
Last Edit: Apr 25, 2013 20:29:04 GMT -5 by nocturnal