Synscan goto to USB

[RandomUsername]

Hi Eveyone

My handset broke on my synscan. I have a USB to RS232, and mating half to use.

Can I go from USB to RS232 to RJ12?  I guess EQMOD software should do the job of the handset?

Does anyone know the pinout of the RS232/RJ12 so I can wire it all up?

Thanks

[Cornelius Varley]

10 minutes ago, RandomUsername said:

Hi Eveyone

My handset broke on my synscan. I have a USB to RS232, and mating half to use.

Can I go from USB to RS232 to RJ12?  I guess EQMOD software should do the job of the handset?

Does anyone know the pinout of the RS232/RJ12 so I can wire it all up?

Thanks

Direct connection to the mount using that type of cabling won't work, you will need an EQDIR module or a diy option http://eq-mod.sourceforge.net/reqindex.html

[RandomUsername]

Thanks for replying.

I don't think I understand. There are enough pins in the RS232, and it is controlled. I'm guessing that the wires out from the mount will just be for two stepper motors inside. Nothing too complicated. Why would you need an extra box?

Do you know the pin-outs for the RJ12 connector?

[Cornelius Varley]

Direct connection between a laptop and the mount doesn't work, this is why you need an EQDIR module to convert the signals from the laptop into something the mount's motor control board will understand (there is a bit more than two stepper motors inside the mount). 

ps the EQDIR module only works on Synscan EQ mounts, not the small AZ-gotos.

[RandomUsername]

I understand that the baud rate may differ, but you only have to monitor the rate, and translate. I had the same issue when trying to make an ODBII cable years ago. Sadly, you can buy a £5 BT version nowadays...

So the EQDIR won't work on my mount..? Any ideas on what will work?

Do you know the pin-outs for the RJ12 connector?

[Cornelius Varley]

1 minute ago, RandomUsername said:

I understand that the baud rate may differ, but you only have to monitor the rate, and translate. I had the same issue when trying to make an ODBII cable years ago. Sadly, you can buy a £5 BT version nowadays...

So the EQDIR won't work on my mount..? Any ideas on what will work?

Do you know the pin-outs for the RJ12 connector?

What mount do you have ? 

[LightBucket]

They are a different type of signal, they need to be TTL signals, thats why you are needing the proper cable with built in electronics, if it was as easy as you say then there would never have been specific cables produced, also the voltage at the mount socket is 12v and this has to be stepped down to 5v before it enters the USB port or it will blow your PC, this is all done with the correct cable..

[RandomUsername]

It is a Synscan AZ goto.

The pin out is 1-Sig, 2-Neg, 3-Link-5, 4-Pos, 5-Sig, 6N/C

There are two motors with encoders inside the mount. Only 4 actual outputs. All you need is two inputs to control the relays for the motors (there's a separate 12v supply for this), and two for signal. If there was sanity used, the motors use relays, the voltage for the relays is normally tiny in comparison.

Therefore, the RS232 needs to just monitor split signals, and run voltages for the relays.

However, if that's not the case, then they've decided to make 12v go direct to power the handset which is probably the case, then all you need is two 12v relays with a 5v trigger. You shouldn't need a complicated voltage convertor.

Do you know what the signal rates are?

Edit: forgot to mention, isn't the RS232 supposed to sort the TTL signalling issue?

[RandomUsername]

Just thought about this; the clever parts are inside the mount (@Cornelius Varley was correct). The 12v output is for powering the handset - the laptop will have it's own power supply. So, I don't need to jack into that.

Don't you just need the two signals?

[LightBucket]

8 minutes ago, RandomUsername said:

Just thought about this; the clever parts are inside the mount (@Cornelius Varley was correct). The 12v output is for powering the handset - the laptop will have it's own power supply. So, I don't need to jack into that.

Don't you just need the two signals?

No, but if thats what you think, then go ahead, but dont moan when your mount starts to smoke and you need a new board..

good luck with it...:)

[Cornelius Varley]

You might find this useful converting a Supatrak mount to goto . The Supatrak and AZ-Goto are basically the same mount so this circuit should work.

[RandomUsername]

58 minutes ago, LightBucket said:

No, but if thats what you think, then go ahead, but dont moan when your mount starts to smoke and you need a new board..

good luck with it...:)

Erm, not sure what would smoke. I wouldn't even be adding voltage.

TTL voltage is 0-5v (serial can up to 13v). The two signal wires are just telling the mount what to do, and letting the source know what's going on. So unless I'm mistaken, the two signals are just communication.

Plugging them in directly to the USB may cause 'unwanted complications', but an active RS232 should iron out those problems.

54 minutes ago, Cornelius Varley said:

You might find this useful converting a Supatrak mount to goto . The Supatrak and AZ-Goto are basically the same mount so this circuit should work.

That's an interesting read. It points to most of what I am thinking. Unfortunately it's for use in conjunction with a hand controller, and mine's broken.

Still, it's jammed with the info I need. Thanks.

[Cornelius Varley]

It can also be used without a handcontroller, that particular circuit Robin (rgw on sgl) created allows you to use a standard Supatrak handset alongside the laptop. It can be used without the handset if required. Also, take a look at this site , (you will need to translate it into English using google translate) which gives another version of the circuit.

[RandomUsername]

Success at last. First off, it's TTL, not serial. Do not connect using USB to serial cable!!!

Pin 2 was earth (yellow for me), and Pin 3 was data (brown for me). You don't need the rest. Odd, but true!

Then, I wired the cable via a USB-TTL connector, downloaded the correct driver and checked the cable. All ok. Connected the earth to earth, connected Tx to Tx signal, and linked the Rx on the USB side to the Tx signal via a 1Kohm resistor. Again, odd, but works by altering the signal for return.

Next: downloaded a terminal (YAT), connected the COM and entered some of the coding noted in the hand book that came with the mount e.g. :R1 and :F1, data came back. I could even move the motors.

I found a programme for my mount (Skywatcher). (Tried ASCOM, no luck. and StellariumScope, no luck. Even with the Skywatcher mount driver!)

http://skywatcher.com/download/software/synscan-app/

It also has the drivers for the mount. It started up, worked. Even has an option for Wi-Fi for when I get my TTi Wi-Fi adaptor. 

Hope this helps future users!

Next step is to ask if I can do the alignment via external sources rather than star set-up. i.e. magnetometer.

Note: I tried using ASCOM and StellariumScope using the new driver. Still got errors, although it did know the mount was there. Guess there's a compatibility error.