Internal pressure sensor
Stroller
stroller at stellar.eclipse.co.uk
Thu Oct 1 16:57:18 CEST 2009
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.
More information about the community
mailing list