Keling DB25 Breakout Board Problem

[jimbar99]

I bought one of these on Ebay before researching it on this site. It came fairly quickly and looks like a quality product, but there was no documentation provided with it. The Ebay auction had no links to any pdf files either, and I had some questions about the hookup. The Ebay page didn't have a link to the manufacturers website either. I sent a couple of messages via Ebay regarding the 3 jumpers (JN1, JN2 and J4) and the proper usage of the 4 power terminals on the board.

I asked a specific question about the power terminals first. They are marked "VDD, GND, GND, +5V" (highlighted in the posted image). I stated that I assumed that one pair might be PC supplied and the second external, but I wanted to be sure and if that was the case, which is which?

The reponse I got was "use the GND". That's it. It makes no sense whatsoever to me. I got no response on the second question about usage of the jumpers (so far).

Then I found the Keling site itself, and reviewed the documentation on the DB25 boards available there, but none of the documentation matches this board. Maybe a new design, I don't know. It did seem like the jumpers on similar boards might be used for a 10VDC supply scenario which I don't have, so I might not need any further information on those if that is the case.

Hopefully, someone on here has had enough experience with this board to provide a clear answer to the power supply question. It seems simple enough but I don't want to take a chance on frying the board or my PC in the process!

Just to summarize, what do I connect to each of the 4 terminals referenced above, if anything?

Thanks for the help!

[wendtmk]

Same board I have. It's the CNC4PC C10 BOB. Here's a link to the board:

CNC4PC

Scroll down and you'll find the literature for the board and some wiring diagrams.

Mark

[jimbar99]

Thanks for the reply, but the board I bought is not the same as the C10 pictured on the link you provided. My board is all surface mount. The C10 as pictured uses conventional IC's. My board has a different number of jumpers on it, and the I/O terminals are different as well. I looked at the pdf file for the C10 and it does not apply to the board I got. The only identifying number on the board itself is "X220826", no part number or manufacturer's ID, but it was purchased from Keling's auction posting on Ebay. Maybe this is a newer version of the same concept, but I can't risk making assumptions about the functionality of it. If there is documentation on the surface mount version of this board describing the hookup and operation I would really like to see it, but so far I haven't been able to come up with it. I will keep looking though. I'm starting to wish I had researched it better before pulling the trigger on this board and bought something else. As of now I can't use this board at all until I get some clarification, and Keling has so far not been forthcoming with the basic information I need.

If you designed this board and are reading this by chance, please let me know what I have bought and how to hook it up properly. Thanks.

[jimbar99]

After searching without any success, I tried google Images search and put DB25 Breakout Board in the search term box, and the first image that popped up was the board that I have. In fact, a lot of the results are the same picture of the board that I have. I checked each link, looking for documentation on the functionality of the board, and the included picture is all that I could come up with. At least it shows some wiring info, although there is no mention of the jumper functionality. Apparently, you can buy this board in bulk from China for as low as $10 a pop according to some of the links I looked at.

At least now I know this board was made in China (it isn't marked as such) and apparently nobody has ever bothered to create or make available any documentation on it, either in Chinese or English. At this point, I would settle for a pdf file in Chinese as long as it has decent pictures!

The lesson I have learned from this is to do my research more diligently and not be impulsive about buying components for my project. If I had it to do over again, would I buy this board? NO I would not. Will I end up buying something else instead? Definitely. Any money I saved by cheaping out on this board was more than offset by the wasted time and frustration in trying to get a couple of simple answers to simple questions. Live and learn.

[wendtmk]

Jimbar,

Sorry, you're right it's a different board, I didn't look close enough. I did manage to find this on Keling's site, not sure if you've gotten a copy of this:

http://www.kelinginc.net/KL-DB25.pdf

It mentions the use of the J1 and J2 pins, but doesn't say anything about the J4. I would assume from the four voltage connections that the two GND pins are tied together, the +5 VDC is obvious, and VDD is positive supply voltage, meaning, I would hazard a guess, if you decide to use 10 VDC this is the place to hook the positive side to.

You don't necessarily have to use the PC for 5 VDC power, though you can. I have a wall wart supplying the 5 VDC to my BOB.

Mark

[jimbar99]

Mark,
I determined that the JN1 and JN2 are simply to tie the two V+ terminals together and the two GND terminals together so you can use a single supply if you wish. Without the jumper blocks, the two sets of terminals are separate so you can use the PC supply for the computer side and an external supply for the interface side if you wish for isolation I suppose. The J4 isn't a jumper at all, it's just two pins that bring out the external power supply potential for easier access I guess.

Haven't gotten it to move the motors yet but I am working on it! At least now I don't feel like I'm in danger of smoking the board.

Thanks for the help.
Jim

[Ron Dunn]

I know nothing (in my best Schultz voice) about that product, but here is my guess.

The picture looks like an optically isolated board, probably designed to protect your PC from spikes sent back from the drivers.

These boards have two separate circuits, each of which needs its own power supply. If I've understood it correctly, the board won't work if both sides are not powered.

You CAN power both sides from the one side by joining the sets of V and G terminals, but that may affect the isolation.

The board I use is the Probotix RF model, which has a similar concept. It can be powered in the manner I've just described, but it is recommended that it be powered from a separate 5V source, and has a USB socket for that purpose.

Does that help?

Ron.

[tpmx57]

I have this same board which i bought from ebay running a new router i just built.
Works fine no problems.
I am using a 5v wallwart to power it.
If your still interested I will provide you a diagram from my router.

[jimbar99]

Thanks for the response. I wouldn't mind seeing your diagram. I haven't hooked the board up yet, and it might save me from making a big mistake. I would power mine from a wallwart as well.

[Kelinginc]

Originally Posted by jimbar99 Thanks for the response. I wouldn't mind seeing your diagram. I haven't hooked the board up yet, and it might save me from making a big mistake. I would power mine from a wallwart as well.

if you have question, pls email to me, if you follow this to connect, it will work for sure
http://www.kelinginc.net/KL-DB25.pdf

[jimbar99]

Kelinginc,
Thanks for the response, but if you notice the same PDF file you referred me to was referred to in a previous response to this thread. I saw the diagram you linked before I ever posted here. My board is surface mount, the jumpers are different and the terminals are different. So far, only tpmx57 has posted a message that indicates that he has bought this same board, and I'm hoping he will post his hookup diagram for me to refer to.

I recommend that you update your PDF file for the board layout as shown in the photo of the actual board that I purchased from you (posted previously). Maybe the board functions the same way as your KL-DB25, but then again, it is not physically the same board as pictured on your website, or reflected in your PDF file, so experience tells me that making such an assumption would not be wise. I assume that if you are importing and selling this board that you should be more familiar with it than anybody. I'm just sayin!

[tpmx57]

Here is a pic,
http://s1186.photobucket.com/albums/...t=IMG_0064.jpg
After closer look it is only slightly different than yours.
The 2 black wires are the +5v and gnd coming from the wallwart
and the red and green are 5v and gnd out to my drives.
They go to a power strip and split to all 4 drives(geckos)
The router is running and the board works as wired.
I havent hooked up limit or e-stop switches yet,just got it running.
Hope this helps,sorry I thought it was identical to yours but is only slightly different.