EQMOd Communicaitons

[ribuck]

Hi All, when EQASCOM communicates to a Synscan mount, does anyone know how the EQASCOM software initiates the serial communication with the mount ?

Are there as specific serial hand shake commands that it uses ? as i've struggled to find anything on the net.

Rich.

[chrisshillito]

It is just a standard serial connection - 9600 bps, 8 data bits, no parity, 1 stop bit. No flow control. All that is needed are three connections - ground, Tx and Rx. At the mount these are TTL signals so to connect directly to a PC serial port you need an RS232-TTL level convertor (EQDIRECT). If using the Synscan in PC-Direct mode the Synscan provides the level conversion.

The communcations protocol itself is proprietary and have not been published by Synta. The protocol has been reverse engineered by the EQMOD team but is not available as open source - a "closed source" dll that provides mount communication functionality is provided freely as part of the EQASCOM distribution.

Chris.

[ribuck]

Hi Chris, Thanks for the info. I hadn't realized that the hand controller was doing the convrsion to TTL. I had been converting the serial to TTL before connecting to the hand controller as myself and another person on the forum measured nearly 7v across the Tx & Rx pins

I had hoped on making a standalone project but it looks like it's going to have to be Windows based so i can use the EQMOd source.

Rich.

[Reggie]

The only thing I can suggest at this point is trying some 'virtual serial' port software which should allow you to connect the mount to the PC and a 'terminal style' program and actually 'sniff' the data as it comes through, and whilst EQMod is 'closed' source it uses ascom so has to implement the methods as laid out by the ascom standard, it might be a place to start but probably won't give you much in the way of code but might give 1/2 an idea of whats going on. Sniffing the data and reverse engineering it or having someone tell you what goes on are your best bets at this time.

there's still no reason that you shouldn't be able to make it standalone, although, as you are already looking at EQMod maybe they will 'add' a module for you that gives you the extra data that you need in an easily readable manner

[chrisshillito]

Hi Chris, Thanks for the info. I hadn't realized that the hand controller was doing the convrsion to TTL. I had been converting the serial to TTL before connecting to the hand controller as myself and another person on the forum measured nearly 7v across the Tx & Rx pins

I had hoped on making a standalone project but it looks like it's going to have to be Windows based so i can use the EQMOd source.

Rich.

Yes, the way it works is the handcontroller talks to the mount using the "Synta" protocol. The handcontroller can oprate with a PC in two different modes:

1. Using celestron protocol drivers - The handcontroller not only acts as a level convertor but also a protocol convertor.

2. "PC-Direct" mode in which case the handcontroller goes "transparent2 and just effectively just does level conversion.

For EQMOD (EQASCOM) we either use the handcontroller in PC-Direct mode or just connect directly to the mount using a level convertor (EQASCOM replaces and improves upon the hand controller in many ways)

It's important to know that the interface to the mount is just concerned with stepper motor control. All the "astronomical" functions that turn the stepper control system into a mount control system are performed either by the handcontroller or EQASCOM driver. So if you want to read RA/DEC etc. you need to be talking to the handcontroller or PC driver - not the mount.

If you go the Windows route you may find that all your needs are satisfied by using properties and methods provided by the ASCOM interfaces of the celestron or EQASCOM drivers. If you find there are properties/functions that ASCOM doesn't provide (and isn't perfect!) then join the EQMOD Yahoo group and ask for them (or join the development team and do it yourself ) - we have a pretty good record in giving folks what they want.

Chris.