ST-4 protocol

[bugle]

Hello all,

I have been looking into guiding under linux, and have been looking at open phd linux.

I would like to make an interface to link phd to a modded eq hand controller (shoe string astronomy style).

Being under linux, the devices I've seen (using ASCOM drivers) I dont think will work.

I would like to develop an interface that will work with the software natively. I would be using an AVR uC and USB-TTL IC (FTDI like), possibly arduino hardware.

Does anybody have details of a serial protocol that would be used? ie the text commands that phd would spit out. Failing this when time permits I will compile and install phd and log the commands to a file and try and reverse engineer them, but if this work has already been done it would save some time.

Once done (although I cant promise when that will be...) I will post everything on here open source style, possibly even complete with pcb artwork if I etch a board, although I will probably knock somesting up using veroboard.

[Gina]

Anything that will work with Linux I am very interested in I have some things I'm planning to control using the Velleman USB interface which someone has written Linux drivers for. I do all my software development for Linux these days and only use Windoze where I have to. We want a Linux version of EQMOD really. EQMOD is so good that it's worth compromising to be able to use it I think,

but I'd rather I didn't have to.

Good luck with your project

[bugle]

Hi Gina,

I looked at using the Velleman USB interface for something a while ago, however, ended up getting into the AVR instead so I could make the project pc free, since then have always been able to use AVRs.

C on the AVR (compiled using avr-gcc) and if a pc is involved Python that side...

Whats the Velleman like and what are planned to use it for? I also looked into a product called LabJack quite a bit, looks promising for pc based projects...

[Reggie]

Skywatcher EQ mounts are accessible in linux via 'indi' drivers I believe but only through the 'rajiva' mod. I don't know any information about it at all, just this link:

! Rajiva's Astroseiten

[Gina]

Hi Gina,

I looked at using the Velleman USB interface for something a while ago, however, ended up getting into the AVR instead so I could make the project pc free, since then have always been able to use AVRs.

C on the AVR (compiled using avr-gcc) and if a pc is involved Python that side...

Whats the Velleman like and what are planned to use it for? I also looked into a product called LabJack quite a bit, looks promising for pc based projects...

I've found the Velleman K8055 interface very useful for controlling things and reading data - both analogue and digital. I provides a simple interface between electronic systems and computer. I plan to use it to control my focussing motor and filter wheel.

I currently use Python in Linux too and there's Python stuff for the K8055 interface card. My weather station software is written in Python.

[bugle]

Although I don't have one, I still like the look of the LabJack devices for pc based stuff. Details here U3 | LabJack, available in the UK for £80 here LabJack U3 USB Data Acquisition and Control.

A little pricey compared to the Velleman I know, but, I think a more professional product. When I was considering one, I spent a lot of time on their support forums and was quite impressed...

For this project, I'm thinking along the lines of a shoestring GPUSB clone.

[Gina]

Cost is something I have to watch closely - I already had a Velleman interface card so no extra cost.