Pre-made IDC 2x8 cable to daisy-chain DMD cables?

The Dot Matrix Display (DMD) is a 32x16 array of high-brightness LEDs for visually striking effects. [Product Page]
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Pre-made IDC 2x8 cable to daisy-chain DMD cables?

Post by victorhooi » Mon Sep 15, 2014 2:28 am


I'm trying to daisy-chain multiple DMD displays together.

My understanding is that I just need 16-way ribbon cable, with IDC 2x8 connectors on the end.

I tried making my own using ribbon cable and IDC crimp connectors with a vise - however, I couldn't seem to get the connectors to line up perfectly straight against the cable. I'm worried that if I plug it in and it's not-aligned correct, there might be a short between adjacent cables, and it might damage the DMD displays.

One option is to buy a special IDC crimping tool, like this: ... dp/3126330

which I assume will make it easier to get straight crimps, compared to using a vise.

My other option is just to buy pre-made cables - I can't seem to find any locally, but I can see some on eBay - e.g.:

2Pcs 2mm Pitch 2x8Pin 16Pin 16 Wire IDC Flat Ribbon Cable ... 0699974016

Would this be suitable? I need a 80cm length, so I'll see if they have it in alternate lengths.

Or is there something else you guys can recommend?


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Re: Pre-made IDC 2x8 cable to daisy-chain DMD cables?

Post by angusgr » Mon Sep 15, 2014 4:49 am

Hi victor,

The DMD IDC connectors are 2.54mm pitch not 2mm pitch. The ebay seller you linked has both sizes, but the listing was for 2mm, so make sure you get the right size. Otherwise it should work fine.

I don't own an IDC crimper and I make my cables using a similar technique to the "vice" technique. I find as long as you're fairly careful the cables are pretty forgiving, the connector "teeth" tend to find the top of the cable OK (I use my fingers to push it until it's just touching the insulation, then apply mechanical pressure to crimp.) Every now and again I sacrifice one by mistake, though!

You can use a multimeter and a couple of pointy bits of wire (breadboard leads are perfect) to check for signal integrity and lack of shorts between adjacent connections before plugging a cable in.


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