ASCOM Command set

alistairsam · #1 11-05-2011, 06:29 PM

Hi,

would anyone have any links to the list of ASCOM serial commands.
i'm building an ascom compatible interface to my microcontroller so i can use software to control my steppers, but can't seem to find the serial command set. didnt find it on the ascom site for developers.

rally · #2 11-05-2011, 07:31 PM

AlistairSam,

Have you tried the ASCOM web site ? - it has all the information, followed by the author himself.

Try here for the overview and then follow the links for each type of device :
http://ascom-standards.org/About/HowWorks.htm

Individual standards are here :
http://ascom-standards.org/Standards/Index.htm

The ASCOM command set is specific to each type of device controller.
eg is it a focusser, rotator, camera, filter wheel, dome, telescope driver (mount) etc

New types of devices need to go though an approval process as does each new ASCOM compliant component.
New properties and methods for existing devices need the ASCOM seal of approval before being incorporated into the standard and being able to be implemented by the ASCOM driver itself.

Good luck with it all

Rally

alistairsam · #3 11-05-2011, 09:50 PM

hi,

thanks for the links.
i still have heaps to read, and not being a programmer makes it harder. i do have some programmer buddies who're helping, but i'm basically looking at using the existing telescope driver interface standard of ascom (Telescope Interface Standard 2.0), and writing a new driver that can be used by software to send serial commands to my electronics.
not sure if thats going to be possible but i'm going to try.

alistairsam · #4 11-05-2011, 09:59 PM

Quote:

Originally Posted by rally

AlistairSam,
New properties and methods for existing devices need the ASCOM seal of approval before being incorporated into the standard and being able to be implemented by the ASCOM driver itself.

Rally

if I stay within a subset of properties and methods of existing devices, i'm guessing it wont need to be approved and incorporated into the standard.
i'll need to write a new driver?

rally · #5 11-05-2011, 10:06 PM

AlistairSam,

Unless you are doing something very new and different the existing ASCOM properties and parameters are most likely going to cover everything you could possibly need.

I still think they will want to vett your driver if you want to promote it as an ASCOM compliant product, but if its just for personal use, then it wouldn't matter.
Your driver talks to your device hardware's processor - so its vendor and device specific.

Rally

alistairsam · #6 11-05-2011, 10:16 PM

Quote:

Originally Posted by rally

AlistairSam,

Unless you are doing something very new and different the existing ASCOM properties and parameters are most likely going to cover everything you could possibly need.

I still think they will want to vett your driver if you want to promote it as an ASCOM compliant product, but if its just for personal use, then it wouldn't matter.

Rally

Hi,
its just for personal use.
i'm not trying to do anything new and different, i think the existing properties and parameters should more than cover basic telescope control, tracking and autoguiding requirements.

hikerbob (Bob) · #7 12-05-2011, 12:18 PM

AlistairSam you could also have a look at http://groups.yahoo.com/group/sgl_ob...ory_automation

The focus there is on Ascom and Arduino's so if you are using a different micro then some part's won't help but you may find some good idea's.

Bob

alistairsam · #8 12-05-2011, 04:39 PM

Thanks Bob

I'm using picaxe microcontrollers because they're very easy to use, and found one user trying to interface a dome control software using ascom with his picaxe.
else i might try and develop a driver that emulates the LX200 protocol because the functions that I need are just for slew, go to and tracking, nothing more. of course that will include position feedback.

this was the picaxe - ascom attempt.

http://www.picaxeforum.co.uk/showthr...ighlight=ascom

i also found this PIC based project using ascom standards that looks interesting.

http://www.nfilipovic.com/electronics/lx200-autoguiding

will post progress if i make headway.

alistairsam · #9 29-08-2011, 09:27 PM

hi,

could someone explain how the concept of adding relays to a mounts hand controller box for autoguiding works or how the older mount hand controllers perform manual guiding corrections

what i don't understand is that for autoguiding, the mount has to be tracking so the RA motor would be rotating at the predetermined tracking rate.
so how would the RA+ and RA- relays or buttons work for manual or autoguiding as RA is already on.
So does RA+ just increase the motor speed by a small increment?

I was looking at these instructions for the shoestring handcontroller modifications to add an st-4 port to a mount that doesnt have an st-4 port.
http://www.store.shoestringastronomy...odGuidance.pdf

Barrykgerdes · #10 30-08-2011, 06:49 AM

Auto guiding is a method of correcting errors in the natural tracking of a mount with RA drive. The RA drive can be a stepping motor or a servo loop system or both. To keep the RA synchronised the controller reads the position of the drive and adds or subtracts correction usually in the form of a pulse to keep the mount pointing in the direction dictated by the total pulse count of the drive system.

To compliment this the drive system usually has a secondary input system that can add or subtract pulses from a device that tracks a star. Depending on the electronics this system can be directly compatable with the mount electronics. The ST4 system is the most common and is used by most controllers however if it is not compatable the control is transfered by relays that can make the systems compatable.

Barry

alistairsam · #11 30-08-2011, 10:15 PM

Thanks Barry,

What I meant to ask if the hand controller switches may not be just simple on/off switches for the electronics, but could be used by the mcu to turn the drive on and off, because when tracking is off, the switches turn on the drive electronics to turn the motors by increments, but when tracking is on, and the same switches are depressed, that is used to adjust the speed of the motors, and that would be by varying pulseswidth or dutycycle?

My drive is picaxe based that has serial input and I can easily translate the lx200 commands that i've seen in documentation to movements for my mount.

But I needed to capture the commands that are being sent over the serial port from planetarium software, especially when you click on connect, I guess it queries for firmware version.
I needed to know what the query and response is so i can get the picaxe to send back the same.

I've got this serial port monitoring software serialmon that can capture any data sent/received over the serial port.
only wish I had a compatible mount.
http://www.serialmon.com/

Tandum (Robin) · #12 30-08-2011, 11:55 PM

Quote:

Originally Posted by alistairsam

Hi,

would anyone have any links to the list of ASCOM serial commands.
i'm building an ascom compatible interface to my microcontroller so i can use software to control my steppers, but can't seem to find the serial command set. didnt find it on the ascom site for developers.

I think you need the driver templates that come in the developer components. In that pack will be a template for mount control. Modify the template as you see fit. The templates are for visual studio 2008 and can be used in C#.NET or VB.NET. The download is here.

alistairsam · #13 31-08-2011, 12:06 AM

thanks for that. will check it out.
meanwhile, i found a null modem emulator that creates virtual com port pairs. http://sourceforge.net/projects/com0com/
so the software connects to one port, and I can use the serial mon software to monitor what goes over the serial port.
atleast thats the intention.
will post results.

I'm not trying to develop any software, just use the lx200 as the telescope in stellarium or cdc and interface it to the picaxe and drive the steppers by translating lx200 commands to subroutines in the picaxe code.

i'm using a quadrature decoder chip, the htcl-2032, that stores absolute position values from an encoder, upto a 32bit value.
i've also developed a mathematical method of translating that absolute value to a degree, minute second value, so once I interpret move commands from the software, i can translate that to absolute positions that the picaxe can move the stepper to.
there is encoder feedback to the picaxe so it knows where the RA shaft is at (encoder is on RA shaft).

alistairsam · #14 06-09-2011, 06:16 PM

finally managed to install a serial port monitor software that captures data sent/received from the port and also an lx200 command set here http://www.astronomy.hu/PulsarLX200commands_v2.3.pdf and here
http://www.mapug-astronomy.net/ragre...0Commands.html
http://soundstepper.sourceforge.net/..._Commands.html

Got stellarium telescope control connected to com1, and can see stellarium querying the current RA by sending #:GR# every few seconds.
I can get the picaxe mcu to send back co-ordinates, will see how it goes from there.