Ribbon cable tester

There’s a ribbon cable tester project at https://github.com/tomarus/cabletester. I forked it and made a PCB for it, with a few minor modifications mostly to do with the ordering of the connections. Seems to work:


The intention is for the display to plug into a header on the board but it turns out these displays come in a couple of versions that look identical at first but have different pin ordering. Aside from that they seem entirely compatible. I didn’t notice until after I received the board and display and found they used different orderings. So I used M-F jumpers to connect this display. They’re cheap enough even from domestic sources (about $7) that I just ordered another one with the other pin order, and for future boards I’ve modified the PCB layout to have footprints for both. I also added mounting holes which were omitted in the first PCB run.

There are Gerbers in the GitHub repository:


A few first run boards are available on Reverb.
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At first i was like: Who needs to test ribbon cables. Then i remember when i built my ADSR i nearly fried it cause of a bad cable.

Apparently me.

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Cheap insurance… I’ve never had trouble with a commercially made cable but now that I’m making my own, I’m not inclined to assume they’re okay.

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Many years of working in experimental physics — much of which involves installing electronic modules in racks and then connecting them with patch cables — taught me that the majority of data acquisition problems are bad cables or bad cable connections. Remember faster than light neutrinos? That was a bad connection. Nasty enough when it’s signal cables, but power cables?

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This is why I won’t use ribbon cables to power modules. Electrical flex is cheap and reliable.

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I never had a problem with a home made cable, but Patching Panda included a shorting cable with a module and both Doepfer and Make Noise have the audacity to make link cables with opposite facing keyed headers. At least at this point (and so far) I know my power supplies shut down before anything fries.

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i have one cable that’s shorted, so a cable tester is a great idea

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It absolutely can happen. BEWARE
ooooOOOOO00000000OOOOOoooooo

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sweet! ordered :slight_smile: TY for getting them up so quickly!

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Great. Something else that can go wrong. :roll_eyes:

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Collect 'em all! …

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image

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Ordered. Thanks for putting these up. Will look over the BOM etc tomorrow

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I suppose putting a link to the GitHub repository in the first post would have been a good idea. Still is. I did.

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I think I will do a Demo Batch for distro in the UK :wink:

Got a few things I need to order from JLC, just need to sort out a few things.

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thank you Richard Holmes, so very much , this time found the BOM layout and code and such, as well as the display type and everything, Stay safe and healthy and well. RT

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EDIT: This isn’t actually reliable at all, though could be repurposed in code.

Pro tip: with the right cable, you can also use this to test modules.

I’ve been trying to find this particular short for days and testing to verify that it’s there doesn’t help me locate it. But, had I tested first, I could have saved myself some skipped heartbeats when my whole system shut down after I plugged it in.

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alright are you selling these :wink:. yeah test equipment like this is really handy to have .

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Richard just got my display GND VCC SCL SDA and my board was from the 1st set so only one pinout for display. Do I have to wrangle the leads around for this board to fit. I don’t see the display lettering on pcb just 3 round solder tabs and a square for the 4th where SDA pin goes , but are the others right way? thanks again one beautiful work of pcb art !!!

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ohh… Forgot to add this to the latest JLC order, just managed to slip it in though… But will now probably get stung for customs charge (or more accurately Royal Mail charging £8 out of £11 to apply a customs charge)

Anyone in the UK interested these should land in a couple of weeks.

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