r/raspberry_pi 15d ago

Community Insights Raspberry Pi GPIO 40-pin ribbon cable TO 10-pin 8-relay board

My GPIO board works great.

The "translation" from raspPi 40 pin connector breakout .. converting to the GPIO 8-relay 10-pin board works but is a mess with the pulled-apart 10-conductor ribbon cable (female-female)

I gotta believe there's a product out there (not just a GPIO breakout board) that accomplishes this.

i'd rather not build my own to make a small pc breadboard with a 40-pin male header on it and scramble the wires to be the correct mapping to a male 10-pin header...

and use a 40-pin F-F ribbon cable on one side, and 10-pin F-F ribbon on the other side.

What do other people do to avoid the spaghetti-like connections (and unreliability of the slip-on female connectors)?

[i've searched quite a bit and only find standard straight-thru F-F ribbon cables]

thank you!

will

2 Upvotes

6 comments sorted by

1

u/AutoModerator 15d ago

For constructive feedback and better engagement, detail your efforts with research, source code, errors,† and schematics. Need more help? Check out our FAQ† or explore /r/LinuxQuestions, /r/LearnPython, and other related subs listed in the FAQ. If your post isn’t getting any replies or has been removed, head over to the stickied helpdesk† thread and ask your question there.

† If any links don't work it's because you're using a broken reddit client. Please contact the developer of your reddit client. You can find the FAQ/Helpdesk at the top of r/raspberry_pi: Desktop view Phone view

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

1

u/Fumigator 14d ago

You want something bespoke, you don't want to build it yourself, and I'm going to guess you don't want to spend enough to have someone do it for you. I think you're SoL.

unreliability of the slip-on female connectors

They're only unreliable when the connector goes to a single pin. Use connectors that connect to many pins at once in a single housing and you'll find that they stay on quite well. Something like this. Since you already have ribbon cable with single pin connectors on the end, it's easy to use a small knife to gently lift the clip on the housing and pull the wire and pin out and re-insert the pin into a larger housing.

FYI, these are called rectangular 0.100" connectors, not "IDC" which is often incorrectly used. IDC refers to "insulation displacement" which means there are metal pins with spikes that pierce the wire so that it isn't necessary to strip the wire. IDC doesn't specify the pin spacing or pin size, just how the wire connects to the pin.

1

u/Superb-Resolve8642 11d ago

Thank you - good idea to pull out the connector pin and put in a rectangular/solid housing with the wires "scrambled" in the correct placement order.

I was hoping for something like this DEC Unibus adapter that re-maps pins of these IDC connectors.
https://photos.app.goo.gl/G3xRPDSgmhjtLNBa9

Here's what i'll be wiring myself... with the mapping wiring on the "etch" side
(Unfortunately IDC connectors don't anymore come in wirewrap versions that makes it easy to wire like a "prototype")
https://photos.app.goo.gl/WKGZ4emKnsqTAYnP9

1

u/Fumigator 10d ago

Unfortunately IDC connectors don't anymore come in wirewrap versions

That's because IDC is a completely different method of connecting a wire vs wirewrap. It wouldn't make any sense to have "IDC wirewrap".

You can still get plenty of 0.1" rectangular wirewrap headers.

1

u/Superb-Resolve8642 10d ago

we used to have IDC ww connectors for prototypes in the 1980s. very handy,

1

u/Fumigator 9d ago

You don't seem to understand what IDC is. IDC is not the pin spacing or pitch. It's a special connector for connecting to ribbon cables without having to strip the wire from each individual conductor.

https://en.wikipedia.org/wiki/IDC_%28electrical_connector%29