"I've Only Just Begun....USB/RS232"

[obscura]

Re my previous post a few weeks ago for advice on scopes etc., I have taken a dip into "Making Every Photon Count" cover to cover 4/5 times. Help here in SL and the book led to the acquisition of HEQ5 Synscan, Canon 350D unmod (for its USB2), Startravel 80, Giga T Pro, QHY5v and bobs and bits. I decided to play with the ST80 tube as a guider and the DSLR to image before deciding on a more upmarket scope. I have aligned the scope's reticle hopefully and just await a clear night to run it all up.

However, I continue to plan ahead with thoughts of EQMOD/Ascom -but that's another day - more mundane things first.

I despair of SW's RS232 interface to a PC!

If I assume a pc connect from the Synscan's RJ11 using the supplied cable, what is the best and cheapest way of getting to a USB port? Shoestring GPUSB looks a tad pricey but I guess its opto isolated. I see Maplin with a male RS232 back to back with a USB connector - but what of the connections and more worrying, delivered volts??? I recall 25V with RS232 I think and 5V pc logic.

I am sure this is a common question so apologies for boring all to death.

Ye Olde Git

[themos]

Cables, Leads and Controllers - HitecAstro EQDIR adapter

The one on the right is a good, readymade solution.

[obscura]

Sorry to appear a mite dim, what is the connection inbuilt to the module? Would that imply an RJ11 to RJ11 cable?

Rgds

Brian

[themos]

The RJ11 end of the adapter plugs into your HEQ5 mount, in the place of the hand controller. You then use a standard "A-B" USB cable to connect your computer's USB port to the adapter.

[obscura]

Perhaps I have been thinking a little too simply. I was thinking the HEQ5 Synscan mount being guided from the pc via the guider to its ST4 port and the DSLR as standalone controlled by the Hahnel Giga. I wasn't thinking at this time of the PC s/w, be it CdC, Starry Night, EQMOD/Ascom etc., controlling the mount, camera etc. I guess I was trying to keep the learning curve a little less steep.

Thinking a little further, I am beginning to think that there is little need to connect the Synscan controller to the laptop - any updates to it can be made on the master pc here.

Once I am in comfort zone with this more basic approach, the Hitec Astro Adaptor looks good when going to total pc control.

Does this make sense?

Many thanks for your help.

Rgds

Brian

[themos]

If you want to connect the Synscan controller to the pc, you'll have to wait for somebody else's advice, I'm afraid.

[obscura]

You have been a great help - more than you know. The penny dropped today.

Best Regards

Brian

[MikeWilson]

If you want to connect the Synscan controller to the pc, you'll have to wait for somebody else's advice, I'm afraid.

1. Plug a Skywatcher RS232 to Serial connector into the SynScan hand controller.

2. Plug a Serial to USB connector into the Serial/RS232 connector.

3. Install drivers on your PC for the Serial to USB connector

4. Connect it all up

5. Switch on the SynScan handset, hit enter through all the various startup questions and when at the main menu, go to "Utilities"->"PC Direct Mode".

6. You're now good to go. Make sure that the correct COM port is specified in whatever software you're using.

[NickK]

The EQ6 interface (direct without handset) is TTL serial not RS232. I've been looking at these in depth for connecting to an EQ6 to a Apple Mac using AOSX.

There are two DIR boxes:

* EQ6 TTL <-[box with MAX232 voltage driver]-> RS232 on Computer

* EQ6 TTL <-[box with FTDI FT232BM or Prolific chip]-> USB on computer

So from this we can see that you don't need RS232 at all. It's just that a lot of the old laptops used have serial ports. The only advantage of RS232 is that it can drive a far longer cable (20 meters for example for proper RS232).

WARNING: the EQ6 exposes 12V lines on pins in the D9 plug to power the handset, so care needs to be taken when connect it up if you use a non EQDIR pre-made USB<->Serial cable (it may short the pins to ground). If you don't know how to check and resolve this - just buy the EQDIRUSB box to save you from destroying the mount.

The nice thing is for me is that after developing the FT232BM transport plugin for AOSX for my ATIK 16ic, I can use it to drive the NEQ6 without the handset! (I have two FTDI chip based cables lying around so I shouldn't need the EQDIR box!)

Active Robots sel lots of USB<->TTL serial stuff including FT232BM based boards. It's then easy to make a cable up to connect it to the EQ6 mount. Just be careful of the 12V pins!

The new SynScan v3 handset (or at least the firmware from my understanding) has a PC direct mode so that you connect to the controller. The problem is that EQDIR's support is experimental at the moment.

[lukebl]

Is this what you need? This is what I use to communicate between my Synscan handset and the PC. All the guiding and ASCOM goes via this black cable which plugs into a USB port. Unfortunately, I can't remember where I got it from (probably Maplins) and it doesn't have any identification marks (apart from the name 'Nikkai'). Cost about £20.

Hope this helps

[NickK]

Yes - the black cable does the USB<->TTL serial then the grey serial extension cable connects to the mount.

However my warning about the 12V lines still applies - both to ensure a crossover serial cable isn't used and that the converter doesn't short pins.

Sorry to be a scaremonger, I just want to make sure that people aren't going to attempt to try just any converter cable without understanding if it will work first.

Luke - just out of interest, what does windows say the black USB cable is? Ie if you look at the USB device - what's the vendor ID and product ID? (does it say Future Technology D..I.. ?)

[lukebl]

Nick, in the Device Manager it just says that it is a 'Prolific USB-to-Serial Comm Port'. Apart from the name 'Nikkai', the only other id is a serial number 0813271 on the other side.

[NickK]

Nick, in the Device Manager it just says that it is a 'Prolific USB-to-Serial Comm Port'.

Thanks for that - Prolific is a competitor to FTDI and the chip does the same job as FTDI's chip. I think as it's a very common chip I'll look at adding support for it into AOSX (provides ASCOM-esque functionality natively on Apple Mac). Sorry for getting a little off topic

[Merlin66]

I been using the Keyspan USB>Serial adaptors for the past five years on everything.....they never let me down...will communicate with all the software and hardware...I recommend them.