I am thinking about buying this gyro. I intend to use it on a quad copter. Will it be able to measure all 3 axis at the same time? Anyone had any luck with this chip?
The clue is in the description "3-axis angular rate sensor"
The datasheet mentions integral low and high-pass filters, but doesn't explain the onboard digital filtering - this makes me suspect it has high-pass filtering fixed in place - not a great feature for an IMU, best to avoid unless you can find out how to defeat this (the datasheet is very poor in this matter)
The problem with high-pass filtering is that it removes the very signal you need to integrate to perform IMU function. Doesn't seem to have stopped people using it. If all else fails you must set the high-pass filter to the lowest cut-off frequency possible.
Thanks for the reply. I knew that it could measure 3 axis. Some people in the reviews said that they were not able to read all three axis at the same time. They could only do one. But I think you bring up a good point, a high pass filter design is not a good idea for this chip. I guess I will go back to searching. The 3 major things I am looking for is the ability to read all 3 axis at the same time, clear resolution, and low noise.
Datasheet didn't seem that forthcoming on sample timing did it? Its probably fast enough for IMU, and ideally you want to know the time of each sample to integrate the outputs with least skew, but most of these devices can sample at 100Hz or more I think.
Not quite true:
Please look at
Datasheet http://www.parallax.com/portals/0/downloads/docs/prod/sens/27911-GyroscopeAppNote2.pdf >> Chapter 4 - Digital filters (page 13) >> Figure 2
The block diagram shows that the outputs (either the normal or the interrupt-based ones) can be configured to provide any of the 4 filtered outputs:
- no HPF, no LPF2
- HPF, no LPF2
- no HPF, LPF2
- HPF, LPF2
Is there something I'm missing here?