My astronomy project:
EQ6 Mount and OnStep driver

Contents:

1. Introduction, EQ6 and OnStep
2. OnStep Hardware
3. Setup FYSETC E4 board
4. Compile & Upload
5. Web browser parameter setup
6. Enclosure and peripherals
7. Installing hardware in mount
8. Temperature, Humid and Pressure sensors
9. Test of auto guiding
10. RA drift
11. To be continued

Related projects:

• EQ6 dismantling rebuilding
• AstroEQ for EQ6
• OnStep for EQ6
• Pier mount

Note:
I take no responsibility or liability for what are written here, you use the information on your own risk!

10, RA drift:

To have the mount track correct in the RA axis the clock that control the speed must be correct. Dependent of the construction it maybe need to be corrected, often ceramic clocks which is not so exact. You notice that the speed is wrong when the auto guiding have to do much more corrections to East or West, it's not symmetric.

Check of RA track:

To check the RA speed I disable the guide in RA, I set the RA Aggressiveness to 0. You can then follow the trend of the RA. Here I do it by control the periodic error if it's symmetric. I got the result -20 to +10. With this non symmetry the auto guider has to work harder and maybe give a more bad error in tracking.

Frequency adjust panel:

The clock that control the speed can be adjusted in the INDI control panel. See tab LX200 OnStep>Motion Control. Each click on a Frequency button change the clock by 0.02 Hz, equal to 0.005 arc seconds per second.

Increase the Frequency:

I increased the clock by 10 click on the Frequency + button. Result, the periodic error, -20 to -4, it was the wrong direction.

Decrease the frequency:

Now I decrease the frequency, by ten clicks on the Frequency - button. Almost symmetric now, -12 to +12. Don't forget to save at the LX200 OnStep>Options menu.