since low cost accelerometers are somewhat noisy, I'd suspect that first.
http://wiki.openmoko.org/wiki/Technical:Accelerometer_Fundamentals Not sure what kind of filter you should use. There should be some guys On the list who can chime in better than I can. Joel Newkirk wrote: > I wrote a short shell script to repeatedly take the raw output from one of > the accelerometers (/sys/devices/platform/spi_s3c24xx_gpio.1/spi0.1/dump) > and massage the data to output X,Y,and Z-axis readings in decimal, -128 to > 128. > > With my Freerunner sitting flat, face up, on the concrete slab of my house, > the 'Z' reading (positive Z is toward the back of the handset, BTW) > fluctuates between 51 and 56. (X and Y range from -1 to 2) That's a > variance of +/- 5%, and I'm fairly confident gravity isn't fluctuating > significantly... ;) > > Is that to be expected, is my Freerunner defective, or am I doing something > wrong? > > I'm trying to develop a simple tool that will determine 'down' based on > output from the accelerometer, and indicate deviations from various > 90-degree orientations - will I need to massage the data further to ignore > variations, should I be averaging several readings, or what? > > j > > > > _______________________________________________ > Openmoko community mailing list > community@lists.openmoko.org > http://lists.openmoko.org/mailman/listinfo/community _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community