should a cobbler have any pins connected to each other?

[benino]

my cobbler has some of the pins connected to each other. is this wrong?
If I cut the traces that are connecting the pins to each other, and can end up with each pin from the pi ending up on its own row on my breadboard will that work?

I'm using an older Pi that a friend gave me. I'm not sure if it's a 256 or 512MB unit.

My cobbler has the following pins connected to each other: 2,7,18,21
I powered up the pi with those pins connected to each other once. Could this have damaged something (based on the pins that are connected to each other? I don't know enough about how the IO pins work.

I added the pi's pin numbers to this diagram I got from adafruit (source: https://learn.adafruit.com/adafruits-ra ... -connector)




Here's the back of my cobbler where you can see the connected pins (verified they are connected with multimeter)

[rpdom]

You've got your cable plugged into the Pi the wrong way round.

Those pins are 25, 20, 9 and 6 - all Ground pins.

[edit] or you are reading the pin numbering the wrong way.

[B.Goode]

If you compare your photo with the diagram I think you will find the pins that are interconnected are Ground connections. It seems perfectly OK to me and does not need modifying.

[DougieLawson]

Here's the back of my cobbler where you can see the connected pins (verified they are connected with multimeter)

That looks perfect to me.

Starting at the "S" of "Support" and working clockwise.

First pin connected by that big track is pin#6, next is pin#9, next is pin#20 (with that track that crosses sides), last is pin#25.

Turn the cable round at ONE END only.

Could this have damaged something (based on the pins that are connected to each other?

YES!

[klricks]

You will need to turn the adapter over to match the diagram. Note that pin 1 is the pin with the square shaped solder pad. Most circuit designers will use a square pad to designate pin 1 for all types of connectors, chips and other 'through hole' components.

[benino]

ugh.
So is there any procedure I can follow, or diagnostic I can run to find out if anything is broken?
I'm completely new to the pi and don't want to start doing tutorials and not know if things aren't working because I made a software mistake, or because I have a hardware problem.

This is the reason I connected the ribbon cable as I did:


It can only be plugged in in that direction. Notice the location of the red "pin one" wire. I wish I'd known the square shouldered pin thing.

[Burngate]

Yes, you can only plug that in one way, but the other end - the end plugged into the Pi - can go either way round.
If you look at the bottom of the Pi, it has a square pad for pin 1. Then you can follow the red wire from pin 1 to pin 1.

Looking at swapping the relevant ones round connects pins 2,7,13,18,21
The worst thing is pin 2, which is 5v, will be connected to four GPIOs, and may destroy them.

So is there any procedure I can follow, or diagnostic I can run to find out if anything is broken?

None that I know of, other than powering your Pi and seeing if it works.
And even if it does, its life may have been drastically shortened - damage can spread, because of localised heating.

[FTrevorGowen]

This is the reason I connected the ribbon cable as I did:

It can only be plugged in in that direction. Notice the location of the red "pin one" wire. I wish I'd known the square shouldered pin thing.

Comparing your ribbon cable (in the photo.) with several of mine it looks as if the error was in the ribbon cable itself - the red-striped-side of the cable should be at the left-hand end of the "polarising-bump-side" of the connector where there should also be a triangular "down-arrow" mark indicating pin 1 (of the connector). (There will also be a similar mark on the topside of the cobbler PCB if it's the same as this one: http://www.cpmspectrepi.webspace.virgin ... ExtBd.html - ie. pin 1 is at the right-hand-front-side when viewed from above the 'T' )
Trev.

[klricks]

The red T Cobblers were like that so you will have to turn the cable on the RPi to match.... (or file the key off and put the red marked wire on pin 1 as it should have been). That was fixed on the blue T cobblers.
See: http://www.raspberrypi.org/forums/viewt ... 7&p=656710

[Burngate]

Comparing your ribbon cable (in the photo.) with several of mine it looks as if the error was in the ribbon cable itself - the red-striped-side of the cable should be at the left-hand end of the "polarising-bump-side" of the connector where there should also be a triangular "down-arrow" mark indicating pin 1 (of the connector).

Yes. I missed that. Sorry.

If it's any consolation, I've had several wired wrongly like that, including a rainbow one, and one that had one end correct, the other wrong. With one like that, you've no chance.

[FTrevorGowen]

The red T Cobblers were like that so you will have to turn the cable on the RPi to match.... (or file the key off and put the red marked wire on pin 1 as it should have been). That was fixed on the blue T cobblers.
See: http://www.raspberrypi.org/forums/viewt ... 7&p=656710

Thanks for the reminder - I'd forgot about that previous topic. Mine was "purchased w/o a cable" and I've always "made my own cables up conventionally".
Trev.

[gordon77]

I would have liked to see the pi pins having one of the earths pins removed so the cables could have been keyed so they cannot be connected the wrong way around.

[Laurens-wuyts]

The red T Cobblers were like that so you will have to turn the cable on the RPi to match.... (or file the key off and put the red marked wire on pin 1 as it should have been). That was fixed on the blue T cobblers.
See: http://www.raspberrypi.org/forums/viewt ... 7&p=656710

I have a red cobbler(bought from DX), but the cable is with the red stripe at the right side.

Laurens

[DougieLawson]

I would have liked to see the pi pins having one of the earths pins removed so the cables could have been keyed so they cannot be connected the wrong way around.

You can still get the IDC connectors* round the wrong way on a cable so it only gives some protection.




* yes I know that's tautology