Slew to first alignment position results in RA axis oscillations

[bgottula]

On 31 March 2024 I ran bootstrap in preparation for tracking ISS. When moving to the first location the mount started slewing in RA only, and upon reaching some position maybe 30 degrees from startup it started to oscillate back and forth by a few degrees around that position. The oscillations stayed at a steady rate and magnitude. After a few of these it was clear that alignment was not going to work so I killed the program. A second attempt soon after produced the same result.

It's noteworthy that I somewhat recently upgraded Gemini to the new Level 6 firmware, where one of the features is 4x encoder resolution. I wonder if the number of ticks per degree in the physical position has changed. That value is hard-coded in probably both this and the point package.

• Confirm ticks per degree in current Gemini.
• Attempt to reproduce the problem with more debug outputs.

[bgottula]

track don't seem to be writing all of the same telemetry channels I had in the past, but I was able to find and plot the commanded slew rates for both axes, and these plots agree closely with my observations. Use this link on nix: http://localhost:3000/goto/ba7ns2xSR?orgId=1

In the plot green is RA axis, yellow is Dec axis, and the Y-axis units are degrees/s.

[bgottula]

I have confirmed that the 4x resolution "quadrature" servo encoder mode was enabled and was in fact the root cause of this problem. I have started to make the necessary updates and tests indoors with these adjustments show expected motion behavior from both axes.