On 30 Sep 2009, at 22:18, Christoph Mair wrote: > ... > I successfully added a pressure sensor to my Freerunner. The BMP085 > chip from > Bosch Sensortec is a small (5x5x1.5mm) chip which includes a > pressure and a > temperature sensor. Power and I2C is enough to get it working. I > glued it next > to the BT antenna. The wiki page contains some pictures: > http://wiki.openmoko.org/wiki/I2C_Pressure_Sensor > Sourcecode is available from http://gitorious.org/freerunner-navigation- > board/bmp085
Cool! How accurate do you find it? This makes the Freerunner a nice mobile for glider / hang-glider / paraglider pilots. They most always carry a varioaltimeter with them, and last time I flew (some years ago) GPS was beginning to have a significant impact upon that (niche) market. The combination of barometric pressure with groundspeed allows one to easily find the optimal speed-to-fly, allowing for head- or tail-wind on a glide between lift sources (thermals). I'm sure that this sensor must be at least as accurate as those used in the cheap commercial ($250) varioaltimeters of 10 years ago, so it looks really good for this sport, if someone has the time to make a nice interface. It would be interesting (for me, anyway) to test by climbing a small hill and see if the pressure difference is reflected accurately. 30m should be a good initial test. Stroller. _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community