From: "Milton Aupperle" <milton@outcastsoft.com>

Date: April 8, 2008 11:11:06 PM MDT

To: Astro_IIDC@yahoogroups.com

Subject: Re: Guiding Celestron mount?



--- In Astro_IIDC@yahoogroups.com, "alien2108" <alien@...> wrote:


Hello Milton!


I think you are not correct about Celestron protocol. First of all

resolution is 0.08 arc seconds.


That's a "theoretical" number. In practice it's far less accurate.



Also moving the scope is very easy in steps. You get the current

position add/substract the amount you want to move (with 0.08 arc

seconds resolution) and issue GOTO to calculated coordinates.


Not according to Darryl Robertson (the creator of Equinox) it isn't

simple nor reliable. Darryl and I talk a lot about stuff and most of

his GPUSB code he added to Equinox was based off of my code. Likewise

Darryl cleared up some issues I had with supporting Meade LX protocols

and shared with me some of his sample code.


And there are 2 protocols for Celestron to deal with, the older text

version and the newer Binary version, which is another complication.


Of course mount should be polar aligned for RA/DEC goto. Alt/Az works

without alignment. 


Alt/Alz is not  accurate sub pixel guiding. None of the great DSO

imagers like Richard Crisp would ever bother with Alt/Azimuth mounts.


But isn't that so with any kind of GEM mount?


I'm not sure what you mean by this at all.


Well I am happy to offer my assistance in supporting Celestron mounts,

since I have quite a lot of programming experience.


I only have 20+ years of software development on the Mac.



Astro IIDC is great program and why not support something as common as

Celestron mount? Equinox, MaxDSLR... all support it.


Because we support the GPUSB and the ST4 guide ports already, which

are far lower latency than you will ever get using serial protocols.

And with GPUSB, I support a large number of mounts too for far less

effort.


Secondly, you've missed one of the advantages in not tying up that

port. You can use a program like Astro Planner or Equinox or the hand

controller to move the scope to a target and then guide off the much

more accurate and lower latency GPUSB with AstroIIDC. So you don't

have to disconnect and re-connect ports when you want to move the

scope and loose the current settings.


HTH..


Milton Aupperle