DK-3 Hand Controller conversion

Questions about hardware and software not obtained from Shoestring Astronomy, but related to our products
Post Reply
centus
Posts: 4
Joined: Wed Apr 21, 2010 12:12 pm
Anti-spam question: Astronomy

DK-3 Hand Controller conversion

Post by centus » Wed Apr 21, 2010 1:10 pm

Hello,

I have a Bresser Messier N150 Newtonian with the dual axis motor drive.
The mount is called MON-2 and the drive is called DUO (says so on the hand controller).
However, after opening the hand controller I found the name DK-3 imprinted on the inside of the case.

Anyway, I am in the process of converting it for auto guiding, and had a question, your conversion kit includes only the wire and connector, while your instructions on how to convert a controller to be usable with GPUSB contain instructions on how to connect a relay in parallel to the buttons.
How do I know what I need to do in my case? if it is as simple as soldering the wires, I don't need the relays, how do I find out?

Thanks,
Or.

dpanderson
Site Admin
Posts: 967
Joined: Fri Apr 28, 2006 1:34 pm
Location: central Iowa
Contact:

Re: DK-3 Hand Controller conversion

Post by dpanderson » Wed Apr 21, 2010 2:13 pm

If all the buttons switches are of the normally-open variety (if you use an ohmeter and measure the resistance across the switch when it is not pushed, it should be a large number, no where close to 0 ohms), and if one side of every switch is connected to the ground node of the board, then you can most likely wire straight into the GPUSB without relays. If all buttons switches are of the normally-open variety but not all connected to the ground node, then you'll need relays in parallel with the switches. If some or all buttons are of the normally-closed variety, then it is a lot more difficult to modify. You would need to wire normally-closed relays in series with the normally closed switches.
Doug Anderson
Shoestring Astronomy
http://www.ShoestringAstronomy.com

centus
Posts: 4
Joined: Wed Apr 21, 2010 12:12 pm
Anti-spam question: Astronomy

Re: DK-3 Hand Controller conversion

Post by centus » Mon May 24, 2010 12:52 am

Just a quick update to whoever looks for DK3 conversion.
I went ahead and soldered 4 dual connector relays in parallel to the switches.
hooked up the +12V coming into the unit to one end of the coils of all the relays and the ground + 4 coils to the ST-4 connector.
GPUSB is now able to press my hand controller buttons!
I'll be testing it out on the scope tonight (weather permitting... :)

Thank you!

centus
Posts: 4
Joined: Wed Apr 21, 2010 12:12 pm
Anti-spam question: Astronomy

Re: DK-3 Hand Controller conversion

Post by centus » Mon May 24, 2010 10:13 pm

It works!!!
Who would have believed my simple mount would ever be able to do auto guiding...

Thank you Shoestring Astronomy!

dpanderson
Site Admin
Posts: 967
Joined: Fri Apr 28, 2006 1:34 pm
Location: central Iowa
Contact:

Re: DK-3 Hand Controller conversion

Post by dpanderson » Tue May 25, 2010 8:30 am

Glad to hear you have it working! Enjoy.
Doug Anderson
Shoestring Astronomy
http://www.ShoestringAstronomy.com

Vixengp
Posts: 2
Joined: Tue Sep 21, 2010 7:50 pm
Anti-spam question: Astronomy

Re: DK-3 Hand Controller conversion

Post by Vixengp » Tue Sep 21, 2010 8:18 pm

Hi, from Holland! I don't know wich shoestring to order!

My handcontroller is the dk-3 (boardname is: KM JH DK-3-A ) it seems mine is simular to Centus his handset.

@dpanderson, can you please explain how the mod of Centus his handcontroller looks like?

dpanderson
Site Admin
Posts: 967
Joined: Fri Apr 28, 2006 1:34 pm
Location: central Iowa
Contact:

Re: DK-3 Hand Controller conversion

Post by dpanderson » Tue Sep 21, 2010 8:26 pm

I don't have any information on this modification other than what is found in this forum thread. You might try contacting Centus with a private message and see if he can help you out.
Doug Anderson
Shoestring Astronomy
http://www.ShoestringAstronomy.com

centus
Posts: 4
Joined: Wed Apr 21, 2010 12:12 pm
Anti-spam question: Astronomy

Re: DK-3 Hand Controller conversion

Post by centus » Wed Sep 22, 2010 6:58 am

Hi,

I might as well re-post the answer to his PM (sorry, I don't frequent this board that often, good thing a PM sends an Email... ;)

Basically I followed the Shoestring instructions for "any other hand controller".
I soldered two wires to each side of each button on the bottom side of the board (in parallel with the buttons).
To know which two are a couple, just use a multimeter and press the button, basically every button is a normally open double switch, so you need to get 4 double switch normally open relays and connect those wires you solder in parallel to the switches to those relays.

I then soldered two wires to the positive and negative poles of the in-coming 12VDC into the hand controller (before the 5V regulator), the positive end is connected in parallel to all relays, the negative one is connected to the ST-4 connector (which I got from ShoeString as a GPKIT-EQ (mostly for the connector itself which is hard to get here in Israel for some reason), as well as the free end of all 4 relays, one to each line of the ST-4:
Pin 1 – White – not used, be sure it is properly trimmed so that it will not short to
anything.
Pin 2 – Black – Common (ground/negative pole of the 12VDC going into the HC).
Pin 3 – Red – RA+
Pin 4 – Green – Dec+
Pin 5 – Yellow – Dec-
Pin 6 – Blue – RA-

That was it, then I just hooked it up to the GPUSB, connected that to my computer and am using PHD to guide with it. Most of my issues are with the quality of my mount, not the GPUSB, it is performing admirably, I've been able to get 10minute shots with no trailing after a good polar alignment!

One point to note is that if you are working with a battery, make sure it is full, these relays have a minimum voltage to operate on, when the scope is tracking and the GPUSB is trying to correct in the direction of the tracking, I started seeing cases where the relay would not close because of under-voltage/current, today, I just use a power supply.

Here's a link to a picasaweb album with some pictures from my HC as it is now, sorry, I didn't take enough pictures during the build process....
http://picasaweb.google.com/or.green/Pr ... directlink#

Good luck to anyone attempting this!

Or.

dpanderson
Site Admin
Posts: 967
Joined: Fri Apr 28, 2006 1:34 pm
Location: central Iowa
Contact:

Re: DK-3 Hand Controller conversion

Post by dpanderson » Wed Sep 22, 2010 7:53 am

Thanks for posting your procedure.
Doug Anderson
Shoestring Astronomy
http://www.ShoestringAstronomy.com

Vixengp
Posts: 2
Joined: Tue Sep 21, 2010 7:50 pm
Anti-spam question: Astronomy

Re: DK-3 Hand Controller conversion

Post by Vixengp » Thu Sep 23, 2010 5:35 pm

Hi Centus,

Thanks for explaining and pics, but it seems that the controller i use is different, as you can see in the pics:
(I removed the 12v to 6v regulator, because it was burned, i will replace it with a new one later)
Image

Image

I don't know where to connect the wires to.

And i don't know if i can use the simple, only connect 5 wires to a JR connector, or the mod with the relay's.

How do i find out?

In advance, thanks for your help!

Barry, Holland

Post Reply