Hi Mat,

Short answer: I did not have success and I gave it up.

Long answer:
I tried different INDI driver:

• indi_azgti_telescope gives many “Serial read error”. I am not sure anymore but I think basic alignment and goto did not work.
• indi_skywatcherAltAzMount which connects directly to the mount. With that driver basic alignment and goto did not work. Even a goto to the alignment point ended in a complete different direction. I got many “Mount Error: Motor not stopped” - maybe the protocol between driver and my mount does not fit.
• indi_synscan_telescope and indi_synscanlegacy_telescope. For both you still need the SynScan App because the driver sends commands to the app which controls the mount. I use the app since long and I like the app! After alignment with the app I can connect with the driver and control the mount. The slew buttons on the app make the fine adjustment easy. But the indi_synscanlegacy_telescope does not support guiding and with the indi_synscan_telescope the guiding pulses do strange things. My mount reacts on these guiding pulses very randomly.

I looked in the source code of the indi_synscan_telescope driver. It uses slew commands (like the slew buttons in the app) for guiding. A guiding command sends a slew to the app and after the guiding pulse length a timer stops the slew again. That sounds simple and straight forward. But for any reason the app does not execute such short slews correctly. Maybe it has something to reject keybounce or there are other timing restrictions in the app.

The indi_synscan_telescope driver uses the "SynScan Serial Communication Protocol" (inter-static.skywatcher.com/downloads/sy...otocol_version33.pdf) which does not support guiding pulses like other mount protocols. The app also supports the "SynScan App Protocol" (inter-static.skywatcher.com/downloads/sy...rotocol_20230902.pdf) which is based on ASCOM's ITelescopeV3 Interface (www.ascom-standards.org/Help/Developer/h...ace_ITelescopeV3.htm). This second protocol is prepared for guiding pulses but I do not know if guiding is implemented in the app (the app should set the CanPulseGuide property to True - I have not tested this). The SkyWatcher support team did not answer my questions. As far as I know there is no INDI driver using the SynScan App protocol. I could not find an evidence on the internet that an ASCOM driver can do guiding with the app and this mount.

On internet you can read that guiding is only possible with an equatorial mount. For my opinion this is a wrong doctrine! It is only easier with an equatorial mount and you will get field rotation with an Alt/AZ - but it is possible and viable. On an Alt/AZ mount the software must adjust both motors. But that should not be an issue for modern computers and microcontroler. Both motors rotate already all the time. For a guiding pulse the software just needs to do some coordinate transformation and adjust the motor speeds for the given time. That can't be so difficult. I am thinking about making my own driver or fixing the issues in the indi_skywatcherAltAzMount when I have more time.


Marry Xmas and Happy New Year,
Ronald

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