Accelerometer output to tilt angle conversion?

[Bobli]

Hi,

For accelerometers such as MMA7660, by reading registers {XOUT, YOUT, ZOUT} the digital output can be immediately obtained.

However, how to convert these outputs into tilt angles? Namely, what is the relationship between physical tilt angle against the gravity/perpendicular axis, and the sensor’s {XOUT, YOUT, ZOUT} readouts?

It should in general be non-linear. Then what is the formula for conversion? Could Freescale provide some help on this?

Bob

[rocco · Accepted solution]

Hi Bob,

It is simple trig. Gravity is a vector, so all you need to do is to treat the three axes as vectors, sum them, and the resulting vector is straight down.

[Bobli]

rocco,

I got it, thanks very much.