Sawtooth pattern in mount axis error
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While tracking Jupiter on 21 December 2020 I noticed that the error in the declination axis had a sawtooth pattern. I'm not sure if this is a bug or hardware issue necessarily. It may simply be an artifact of the encoder resolution and the fact that the mount is tracking a sidereal object and is polar aligned so the motion in the declination axis is very slow compared to what I normally do.
Investigate and determine whether this behavior/telemetry is normal or a problem.
Looks like each step in axis 1 position is 0.00015 degrees, or 0.54 arcseconds (with possible rounding error due to the number of digits of precision shown in the Grafana data tip). This turns out to match up with the encoder resolution. The encoders have 1152000 ticks per half revolution (180 degrees) which is 6400 ticks per degree, or 0.5625 arcseconds per tick. So what I'm seeing in telemetry is just an artifact of the encoder quantization error on the axis position.