I have been struggling with the HP filter for a while trying to bring the HP line high (for about 20-30 usec) between
the cycles of mesurement (of about 2 ms) to "reset" the HP filter, which was suggested in the documentation,
but it did not help!
Eventually, as was suggested in the thread, I shorted the HP filter capacitors; however I was not able to take out the
I MHom resistor - too small for my soldering iron
But even with the resistor in place my sensor now works fine without
these strange aberrations - thanks to the people on the thread who first pointed out this defficiency!
My last complain regarding this sensor is related to the "underpowered" direct (non-amplified) output of the gyro: if I do
individual measurements once every 10-20 msec everything seems to be OK; however if I switch my ADC to do
measurements in a constant loop after a few milliseconds the signal starts to drop (with the board stationary!) to very
low values indicating an ever-increasing rotational speed.
This forced me to switch to the amplified outputs, which brings 2 disadvantages: first, it limits the rotational range to
300 degree/sec, which can be exceeded at sharp movements (adversely effecting the precision of angle integration),
and, second, it precludes me from using the reference voltage provided by the sensor so I have to spend 5-10 seconds
on every start to calibrate gyros. buffering direct outputs from gyros would further improve this IMU.