Why 2 accelerometers?

Al Johnson openmoko at mazikeen.demon.co.uk
Fri Sep 18 17:05:14 CEST 2009

On Friday 18 September 2009, RANJAN wrote:
> Hi,
> I was wondering why FR has two accelerometers.They could have one 3 axis
> accelerometer and a single angular rate gyro.How is a combination for 2
> accelerometers more useful than one 3 axis accelerometer and a gyro?

Or, better, use a 3-axis magnetometer instead of a gyro.

At the time the FR was designed, gyros were significantly more expensive and 
less available than accelerometers, and magnetometers were large and even more 
expensive. Spaced accelerometers sounded like a good way of getting most of 
the way there while still being affordable. In practice it doesn't work so 
well. In the meantime gyro and magnetometer prices have tumbled. 

More information about the devel mailing list