Help With Pin Outs Please

[Stephen]

So the level of my sparky-ness extends to being able to cut, crimp and solder - but when it comes to working out wiring and pins I get lost rather easily

Could someone help me work out what the wiring/pin layout would be to connect a Rigel nStep Stepper Motor Controller to my Moonlite Focuser (I think it's RJ11 on the controller side and serial on the Moonlite side.)

Thanks in advance!

[AstroTux]

Not quite sure what you're asking for here having looked at both the Rigel nStep and the Moonlite focuser - are you trying to just connect an nStep and motor to your focuser or are you trying to connect a Moonlite motor to an nStep?

Either way it would seem that the nStep uses USB to your computer, and the RJ-11 connects directly to the stepper motor. As RJ-11 has 4 pins, as does the stepper motor, then this simply provides the power to each coil of the motor.

To attach your own motor you should establish which wires on it connect to each coil. By using a multimeter you should be able to measure a small resistance between two wires and an open circuit between either of them and the other two. Each pair of wires that has a small resistance is connected to opposite ends of the same coil. Call one of these connected pairs wires 1 and 2, and the others wires 3 and 4.

When wiring a bipolar stepper motor there are only three possible ways of connecting to it and if you get it wrong it should not damage anything, the motor will just not run properly. It may seem like there are more ways but each subsequent pattern is just a repeat of previous ones. The possible patterns from the RJ-11 are 1234, 1324 and 1342. When you have found the right pattern the motor may run in reverse, if so simply swap the connections over on one of the pairs and the motor should run correctly.

BTW, if your motor has 5 wires then it is a unipolar motor. This could probably be used by ignoring the centre tap wire. If you want to know how to identify this there are plenty of explanations on the Internet.

Hope this helps, but I'm sure someone else can provide better info :grin:

Alan

[Stephen]

Thanks for all the info, I'm trying to connect an nStep to a Moonlite hi-res stepper motor - the motor has a serial port on it whereas the nLite has the RJ11 or 12 port

[AstroTux]

I think you'll find that the 'serial' port is just the type of connector that has been used. I very much doubt that the stepper motor actually has a serial interface.

How many wires connect from the motor to the 'serial' interface? If its four, then I would guess that these are the connections to each coil. Have you tried measuring them with a multimeter and seen what the results are? That would help to identify it.

Alan

[Stephen]

I think you'll find that the 'serial' port is just the type of connector that has been used. I very much doubt that the stepper motor actually has a serial interface.

How many wires connect from the motor to the 'serial' interface? If its four, then I would guess that these are the connections to each coil. Have you tried measuring them with a multimeter and seen what the results are? That would help to identify it.

Alan

This I can't tell you I'm afraid, the motor is housed in an enclosure that's attached to the focuser at the point of manufacture - they're not available as after market options (at least at the time I bought it.) There's a slip clutch mechanism so you don't have to use it, but you'd have to take it apart to find this information and I'm not going to do that

This isn't my focuser, but the motor housing is the same

[AstroTux]

Ahhh. Now I see what you mean :grin: . How do you normally connect it, or have you never done this before?

Reading between the lines here http://www.focuser.c...ge=motorstepper it says "The stepper motor's 9 pin DBA connector is compatible with other stepper motor controllers such as the Robo focus controller, James Lacey Brand, and the Cercis brand controller. However a controller has to be used, the motor can not plug directly in to a PC and operate." This says to me that the interface is not a serial interface but a direct connection to the motor.

Having 'played' with similar devices my gut feel is that the controller contains a micro-controller to interface between the PC ( USB ) and a motor driver chip ( the L293 is a commonly used device ). This provides a direct connection to any bipolar stepper motor.

I've just had a look for focus controller pin outs and stumbled across this link that may help http://www.geminitel..._FocusR_eng.pdf . Have a look at the appendix on page two, this may help you.

Alan

[Stephen]

It's normally controlled by a Hitech USB Hub - but I'm looking to remove this from my set up in favour of smaller disparate parts that I can velcro/tuck away in various places on the mount/saddle.

Right I think I understand that

That certainly points me in the right direction thank you

[AstroTux]

No probs. It may be worth just checking the pin outs on your focuser with a multimeter first. If two pins have a resistance lower than about 150 ohms between them, then you can almost guarantee they are connections to the stepper motor coils.

Good luck,

Alan

[rigelsys]

Hi Stephen,

Drop me an e-mail at rigelsys@cox.net and I'll give you the pinout from the rj12 to DB9 connector. I recommend buying (should be available down there) the rj12-db9 female adapter, where the user can pick the pinouts . Looks like this.

http://www.sfcable.c...CFYKd4AodMhMAPw

best regards

Leon Palmer

Rigel Systems

Thanks for all the info, I'm trying to connect an nStep to a Moonlite hi-res stepper motor - the motor has a serial port on it whereas the nLite has the RJ11 or 12 port

[rigelsys]

not a problem, I supply the rj12 to db9 with the nSTEP when requested at ordering time. Am out of town today, will post pinouts using the adapter when I get home. It's pretty quick and easy. adapter also supports robofocus motors that use the DB9, and I've also done some others.

[rigelsys]

ok here's the pinout, color of wire from RJ12 end, to DB 9 pin number

yellow to pin 1

blue to pin 2

red to pin 3

green to pin 4

black to pin 5

white to pin 9

also works with robofocus motors. I've also done the optec DB 9 connector if anyone's interested its

yellow to pin 5

blue to pin 6

gree to pin 8

red top in 7

black to pin 2

white to pin 2

[Tinker1947]

Are the RJ11(Syscan cable) and the RJ12 the same pinout both seem to have 6 pins and the Syscan Cable used for updating firmware ect comes with a 9 Pin female connector.....????

[Tinker1947]

Are the RJ11(Syscan cable) and the RJ12 the same pinout both seem to have 6 pins and the Syscan Cable used for updating firmware ect comes with a 9 Pin female connector.....????

Just checked my RJ11 to DB9 cable, they only use 4 of the pins, there's 6 in the mount connector....but it upgraded the firmware fine.....maybe no good for the threads theme......

[rigelsys]

You're correct, using RJ11 to DB9 as a RS-232 cable substitute (Tx, Rx, CTS, CTR), won't work with the steppers.

[blackdragon72]

On 18/05/2013 at 18:05, rigelsys said:

ok here's the pinout, color of wire from RJ12 end, to DB 9 pin number

yellow to pin 1

blue to pin 2

red to pin 3

green to pin 4

black to pin 5

white to pin 9

also works with robofocus motors. I've also done the optec DB 9 connector if anyone's interested its

yellow to pin 5

blue to pin 6

gree to pin 8

red top in 7

black to pin 2

white to pin 2

I have a moonlite controller and am wondering if it can be use to control Feathertouch/Opetc HSM motor? It is not clear to me whether HSM is bipolar or unipolar motor?