Re: My Skywatcher 150p on an EQ3-2 mount and OnStep STM32 Bluepill #EQ3


hi, not at home at the moment... I did some testing some minutes ago, my issue is the DEC Axis. 

Due there are new customs regulations in the EU it does not make sense anymore to order this at aliexpress. But other people run it with the same pulley. 

Attached the test protocol, maybe Khalid or someone has got a hint for me?

These are my settings: 
Axis 2:
1:65 Wormwheel for DEC and 20 to 40 Gear reduction depends on the pulley

Drive design:
  • Motors and drive components move the mount reliably, not slipping or skipping steps.




  • See the Wiki section here for "Preliminary Firmware Configuration" instructions.


  • Correct stepper micro-step mode is set and actually used in the driver (hardware/connections setup.)


  • Motor direction of motion is correct.
    • Use a planetarium program for control, start tracking; these instructions apply Eq mounts.

Its a EQ Mount OK

  • Move Declination a little (10 or 20 deg.) left and right of the home position (NCP/SCP) and watching from behind the mount see if the telescope movement matches the screen.  Reverse Axis2 if it goes the wrong way.

MATCHES the screen OK

  • Once that is working do a goto to a point half way up in the sky but not too far in home position (40 degrees away or so.)  If it points down toward the ground RA needs to be reversed.

USED MIRACH -> Points UP not down OK

  • Correct steps per degree settings for Axis1 and Axis2; these instructions apply Eq mounts.
    • Use a planetarium program for control, start tracking.
    • Move Axis2/Declination a fair bit (45 deg.) left or right of the home position (NCP/SCP) and take note of the angular distance traveled, is it about 45 degrees?

Started at 90° scale MOVED 45 ° in OnStep ends at about 55° on scale -> 10° missing

Moved 90 ° in Onset ends at about 19° -> 20° missing

  • Move Axis1/RA to near the Meridian and 0 degrees Declination and take note of the angular distance traveled.  Did RA move 90 degrees?

Started at 8h 6m ends at 14h 00m -> 6h -> 90° -> OK



Does anyone have got a hint?

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