Build a patch panel for the GPIO ports on a Pi

Question

I don't like the idea of casual experiments where attaching jumpers straight to GPIO pins is a common activity. I would actually prefer the Raspberry board remain safely affixed to a lab-board, with a separate break-out panel/board for the GPIO lines.

My first thought is a cable from the GPIO 'plug' on the Pi board to a panel of sockets (the 21st century equivalent of 'banana plugs' for jumper leads, and my second idea is to break out the GPIO contacts onto a type of breadboard, with multiple connection possible to each GPIO line.

E.g. the Raspberry site has a number of practical examples of attaching simple components directly to the GPIO pins on the Pi board. I would much rather run a jumper from my patch panel to a breadboard, and mount the component on the breadboard. This way the main Pi board remains untouched and safer during a lab session.

Has anyone built anything like this, and if so, what did you use? Being an electronics enthusiast I would prefer to build my own 'lab board' for the Pi than just buy whatever I need.

Answer 1

I think the normative way to avoid hassles with the GPIO breakout on the pi itself is to attach a ribbon cable and put a further breakout on the end which is compatible with a common breadboard. Here's an example. Adafruit calls this a "cobbler", which I believe is a play on "pie" and not an actual electronics term. There are other are other similar things available -- Sparkfun also has one. These are for 26 pin models but there are 40 pin ones as well (e.g. this one from Canakit). Note they are not necessarily T shaped; some simply fit the cable end directly onto the board (an "I" shape), much like my hack job below.

It would not be that hard to make such a thing yourself by sawing a slice of PCB prototyping board (or just finding one of an appropriate size) and soldering pins in the right places.

I don't consider attaching jumpers directly to the pi a big deal, but I do have a case that doesn't expose them, and has only a side slot for a ribbon cable. At some point I was too impatient to mail order anything so I did the below.

In case it's not clear, the issue is that the spacing of the holes on the end of the ribbon cable isn't wide enough to span both sides of the board, so attaching the cable directly to pins means you need to use either one row or the other (or trash the pi by connecting them both on the same side). However, if you bend one row of pins to a right angle with a pliers, you can get it to span the gap. I don't particularly recommend this in place of a proper breakout since it is quite a hassle to get it to fit (so much so I haven't detached it since; it is firmly attached due to the tension in the pins), but it works. It is also a bit sketchy in that the bare pins are exposed on one side, meaning not safe to play with drunk in dim lighting ;)

The advantage of this is that ribbon cables, pins, and breadboards are cheap and easy to find in local electronics stores.

Answer 2

Here is a nice breakout that plugs straight into any breadboard and its already labeled so you know exactly what pin you are plugging into.

Assembled Pi Cobbler Plus - Breakout Cable for Pi B+/A+/Pi 2