EQ3-2 + Enhanced Duel Axis + ST4 + PHD2 ?

[Laurieast]

Hi All,

I'm trying and failing to use PHD2 with an EQ3-2 (Not Pro or Synscan).

I have the EQ3-2 and Enhanced duel axis motors, a Zwo ST4 cable, a Serial port to USB adapter from my ETX, and tried to install GPUSB but the laptop does not like that.

Have read this and think I understand most of it https://stargazerslounge.com/topic/136565-guided-eq3-2-write-up/#comment-1364449

But I can't find a way of connecting to the mount in PHD2, the ZWO 120mm mini connects fine.

I suspect the Serial port to USB adapter , but the Zwo item is no longer available, maybe there is something else?

Lost in space now!

Thanks for any insight!

 

[ONIKKINEN]

Did you try "on-camera" option for the mount control? Thats meant for ST-4 guiding.

[Pixies]

USB-serial adapters are the work of Beelzebub! Getting one to work on one machine even when it works fine on another is not that straightforward.

 

There are quite a few available but it can be hit or miss. Do you have a local IT shop where you can try a few out to see which one might work?

[Laurieast]

5 minutes ago, ONIKKINEN said:

Did you try "on-camera" option for the mount control? Thats meant for ST-4 guiding.

Yes I did and that did work, but I was not sure if that was the right way for the laptop to talk to the motor drive handbox via the ST4, but if you say so I will try that again.

Testing anything with eternal cloud cover is the usual problem!

Thanks.

3 minutes ago, Pixies said:

There are quite a few available but it can be hit or miss. Do you have a local IT shop where you can try a few out to see which one might work?

Nothing like that for miles, there is this but.. https://www.amazon.co.uk/Skywatcher-Telescope-Control-Serial-Converter/dp/B07HL2Z741/ref=asc_df_B07HL2Z741/?tag=googshopuk-21&linkCode=df0&hvadid=499393282480&hvpos=&hvnetw=g&hvrand=15273921679366876470&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9046380&hvtargid=pla-712410493185&psc=1

Thanks Pixies.

[ONIKKINEN]

3 minutes ago, Laurieast said:

Yes I did and that did work, but I was not sure if that was the right way for the laptop to talk to the motor drive handbox via the ST4, but if you say so I will try that again.

Testing anything with eternal cloud cover is the usual problem!

Ah yes, the testing cycle of one month. Very familiar with that unfortunately 😆.

ST-4 through the camera should work just fine, although it is less accurate than PHD2 guiding through the mount. But i dont think a non go-to controller will be able to do the normal PHD2 guiding. The mount doesn't "talk back" to the PC or the camera with ST4, it just receives instructions from the camera, hence the on-camera mount selection.

[Laurieast]

With  dust cap on guide scope

 

Edited November 6, 2021 by Laurieast

[malc-c]

No expert here, but I presume you have the gear set up in the following way?

• USB lead form laptop to guide camera
• ST4 cable from camera to ST4 port on the enhanced motor controller 

That old thread referred to the standard controller which was modified to use that ST4 adapter, so the adapter shouldn't be needed.  Basically ST4 is a system where it mimicked the pressing of the directional buttons.   So if PHD2 sees the mount drifting, it sends a command to the camera to move the mount in the opposite direction.  The camera then connects which ever wire on the ST4 cable that corresponds to that direction to the internal 5v supply and the control box sees that as a button press and advances the mount.  Naturally it's a little more complicated than that, but in essence that's how it functions.   You have to tell PHD2 that you are using on camera setup, otherwise it will look for an EQDIR type setup where the mount is controlled independently. 

[Laurieast]

8 minutes ago, malc-c said:

• USB lead form laptop to guide camera
• ST4 cable from camera to ST4 port on the enhanced motor controller 

Thanks Malcom, yes did it exactly like that, and connected in PHD with "On Camera".

But I bought some kit from FLO, so likely to stay cloudy for some time before I can test it! Might try it on a distant street light 🤔

 

[malc-c]

1 minute ago, Laurieast said:

 

But I bought some kit from FLO, so likely to stay cloudy for some time before I can test it! 

 

So you're to blame then  😁