After flashing my Raspberry Pi with the latest StellarMate OS running KStars 3.5.5, I ran into serious auto guiding issues that prevented me from imaging.  PHD2 would take 10-15 minutes to calibrate, and when it was done I would get a warning about the DEC and RA calibrations being far off.  When I reviewed the calibration data, I could see the RA axis had calibration points that were far outside of the norm.  When I tried to guide, I'd get a total RMS of 12 arcsec -- unusable.

 

After troubleshooting on the second night, I realized that the INDI Control Panel was set to ENABLE PEC even though PEC was disabled in the hand controller before connecting.  As everyone knows, you cannot auto guide when PEC is enabled on an iOptron mount.  Once I turned that off and saved the INDI driver configuration, my calibrations ran perfectly and my guiding was back down to ~0.6" total RMS.  The default behavior of the INDI driver should be to DISABLE PEC (since PEC is most often used for imaging, and imagers typically guide).

Another change I made to the iOptron INDI driver configuration was to disable tracking.  When I connect to the mount, I don't want it to track until I slew somewhere (e.g. I may be doing a polar alignment at startup).

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