BMX160 in suspend mode

[siiid]

I'm trying to use the BMX160 in a very low power application that requires a 9-axis reading once every 4 hours. We would like the leave the sensor entirely disabled for the most part to acheive the lowest power consumption, but need to wake it every 4 hours to collect the sample. My question is how accurate that reading will be if we bring up the sensor, take a reading and turn it back off periodically like this?

[Vincent · Accepted solution]

BMX160 is 9DoF sensor which has combination of accel, gyro and magnetometer. 

For Accel and Gyro,  there is no any problem to wake up every 4 hours and give you the accurate output. 

For Magnetic sensor, you need to consider the magnetic environment changing.  if the environement is quite stable in this 4  hours, then it is also OK to turn on every 4 hours to get accurate output.

But normally the magnetic environment is changing time to time,  so you need to consider this effect in your applicaiton. 

[siiid]

Okay that makes sense, thank you. Do you have any idea how long the mag would need to be left on to sufficiently calibrate to get a reasonable reading?

[Vincent]

It depends on the calibration method. 

The triditioanal magnetic calibration method needs a 8-figure movement and move slowly for several times.  this means you need at least 10 seconds to get magnetic calibration done.