Low profile GPIO jumpers

[bkenobi]

I have a Raspi B installed in a basic case. I am not currently using the GPIO's, so I didn't realize when selecting a case that they were basically blocked since the case is too close to the pins to allow a standard 1P Dupont jumper to be installed. I tried to connect a couple jumper wires and found the case did not quite close and the jumper wires we basically pinched at a 90 degree angle. I took a couple jumpers and sanded off as much plastic as I could which looks like it might mostly work, but I'm not very happy with the result since it only saves maybe 1/8".

Does anyone make low profile jumpers? If not, the only real options I see are cutting a slot in the case for the GPIO's, grinding the connectors down even more, or finding a different case.

This is my case:
http://www.vetco.net/catalog/product_in ... s_id=15176

As you can see, the case has a slot for installing a side mount GPIO connector, but I don't need a fully populated header.

[DirkS]

You could use something like: https://www.modmypi.com/gpio-accessorie ... -male-pins
Or make your own using https://www.modmypi.com/gpio-accessorie ... ctor-black and a ribbon cable.
Then cut out the parts of the ribbon cable you don't need.

[ame]

Or make your own using https://www.modmypi.com/gpio-accessorie ... ctor-black and a ribbon cable.
Then cut out the parts of the ribbon cable you don't need.

Or use that same connector and insert wires only at the positions you need. It's a bit fiddly to hold them in place while you crimp it down but it works.

[bkenobi]

I thought about using something like this:
http://store.acmeun.com/products/26-pin ... angle.html

But, I'm not sure if that would fit (no dimensions provided).

I thought about using a standard ribbon cable and cutting off the extra wires. The only issue I see with that is that right now I'm only planning on using 2 pins (1 GPIO, 1 ground) but if I decide to add another device I'd have to start from scratch to add the other GPIO pins.

I have never seen someone use a vice to attach header connectors to ribbon cable. I tried to do that by hand with a pair of pliers and failed pretty quickly.

[DirkS]

Or make your own using https://www.modmypi.com/gpio-accessorie ... ctor-black and a ribbon cable.
Then cut out the parts of the ribbon cable you don't need.

Or use that same connector and insert wires only at the positions you need. It's a bit fiddly to hold them in place while you crimp it down but it works.

That was my first idea, but I thought it would be very hard to keep them in place while crimping it down...

[gordon77]

I thought about using something like this:
http://store.acmeun.com/products/26-pin ... angle.html

But, I'm not sure if that would fit (no dimensions provided).

I thought about using a standard ribbon cable and cutting off the extra wires. The only issue I see with that is that right now I'm only planning on using 2 pins (1 GPIO, 1 ground) but if I decide to add another device I'd have to start from scratch to add the other GPIO pins.

I have never seen someone use a vice to attach header connectors to ribbon cable. I tried to do that by hand with a pair of pliers and failed pretty quickly.

Dimensions shown in features list below it on web page !! - (L x W x H) 33.0 x 12.5 x 8.2 mm

[DirkS]

I have never seen someone use a vice to attach header connectors to ribbon cable.

There's a video of Gert van Loo demonstrating it: http://www.raspberrypi.org/make-your-ow ... with-gert/

Another idea: make a short ribbon cable with a female connector on one end and a male (box) header on the other.
That way you have all the pins available outside the case

[Burngate]

I have never seen someone use a vice to attach header connectors to ribbon cable. I tried to do that by hand with a pair of pliers and failed pretty quickly.

I thought everyone used a vice!
I know you can buy specially made crimping devices for mega-pounds, but the one time I tried one, it all went pear-shaped. At least with a decent vice gravity keeps it in place while my hands shuffle the cable around.

[rpdom]

I thought everyone used a vice!

Vice, pliers, hammer, shoe (with foot in) and on one desperate occasion, teeth

[BMS Doug]

I have a Raspi B installed in a basic case. I am not currently using the GPIO's, so I didn't realize when selecting a case that they were basically blocked since the case is too close to the pins to allow a standard 1P Dupont jumper to be installed. I tried to connect a couple jumper wires and found the case did not quite close and the jumper wires we basically pinched at a 90 degree angle. I took a couple jumpers and sanded off as much plastic as I could which looks like it might mostly work, but I'm not very happy with the result since it only saves maybe 1/8".

Does anyone make low profile jumpers? If not, the only real options I see are cutting a slot in the case for the GPIO's, grinding the connectors down even more, or finding a different case.

This is my case:
http://www.vetco.net/catalog/product_in ... s_id=15176

As you can see, the case has a slot for installing a side mount GPIO connector, but I don't need a fully populated header.

you could get some female pin crimps and either shorten them as much as you desire or bend them to a desired angle, then apply heat-shrink to insulate.

you could wrap bare wire around the pin and apply an empty header connector to hold the wrapped wire in place.

[boyoh]

I have a Raspi B installed in a basic case. I am not currently using the GPIO's, so I didn't realize when selecting a case that they were basically blocked since the case is too close to the pins to allow a standard 1P Dupont jumper to be installed. I tried to connect a couple jumper wires and found the case did not quite close and the jumper wires we basically pinched at a 90 degree angle. I took a couple jumpers and sanded off as much plastic as I could which looks like it might mostly work, but I'm not very happy with the result since it only saves maybe 1/8".

Does anyone make low profile jumpers? If not, the only real options I see are cutting a slot in the case for the GPIO's, grinding the connectors down even more, or finding a different case.

This is my case:
http://www.vetco.net/catalog/product_in ... s_id=15176

As you can see, the case has a slot for installing a side mount GPIO connector, but I don't need a fully populated header.

Why is it as soon as some get a Pi
They want to seal it in a box, and
make the connections inaccessible
I don't think the Pi was made to be
sealed up, The object of the GPIO
pins is to interface with external
connection, this is best don using
a ribbon cable. If you don't want to
use the GPIO pins, Why buy a Pi
you can play games & watch videos
on your home computer.

[bkenobi]

you could get some female pin crimps and either shorten them as much as you desire or bend them to a desired angle, then apply heat-shrink to insulate.

you could wrap bare wire around the pin and apply an empty header connector to hold the wrapped wire in place.

this! I sorta considered this originally but thought it would be poor form for some reason. I actually stopped sanding the plastic to make sure the crimped part of the connector wasn't vivisible.

[bkenobi]

Why is it as soon as some get a Pi
They want to seal it in a box, and
make the connections inaccessible
I don't think the Pi was made to be
sealed up, The object of the GPIO
pins is to interface with external
connection, this is best don using
a ribbon cable. If you don't want to
use the GPIO pins, Why buy a Pi
you can play games & watch videos
on your home computer.

I use this as a Home automation system. I didn't need the GPIO's before since I was using other tech exclusively. GPIO solves one problem for me now, so I want to try it. the case makes it wall mountable, more neat, and less appealing for someone to mess with. I see that many cases have a knock-out for the GPIO's, but mine does not.

[DougieLawson]

Why is it as soon as some get a Pi
They want to seal it in a box, and
make the connections inaccessible
I don't think the Pi was made to be
sealed up, The object of the GPIO
pins is to interface with external
connection, this is best don using
a ribbon cable. If you don't want to
use the GPIO pins, Why buy a Pi
you can play games & watch videos
on your home computer.

I had one of my Raspberry Pi model Bs in a home-made case once. It was made by cutting & folding a sheet of A4 card. I took it out to play with the GPIO pins and it's never been cased since. http://www.raspberrypi.org/the-punnet-a ... -for-free/

[rpdom]

Why buy a Pi
you can play games & watch videos
on your home computer.

Because my home computer uses a few hundred watts of power and is noisy, while my Pi uses less than a handful of watts and is silent
(Some of my Raspis are in boxes)

[Mandrewpi]

I use a cobbler made for the pi and I can use a breakout board or the connectors

[aTao]

if you are still stuck then there is always wirewrapping.
I did look for some proper wirewrap wire, but its a daft price.
So.. get some enamelled copper wire, strip the enamel from a few cm at one end then wrap that tightly round a GPIO pin. Start with as close to the end of the wire as you can, hold it with pointy pliers then work up the wire, stopping only when at least 1 turn of enamel has wound onto the pin. It is a pretty secure joint and if the GPIO header pins have any kind of edge to them you actually get a weld at the corners.

[boyoh]

Why buy a Pi
you can play games & watch videos
on your home computer.

Because my home computer uses a few hundred watts of power and is noisy, while my Pi uses less than a handful of watts and is silent
(Some of my Raspis are in boxes)

I'm sorry I did not know that the Pi
has a high power gaming
graphics card with a heat sink
and cooling fan just taking a few
watts

[BMS Doug]

you could get some female pin crimps and either shorten them as much as you desire or bend them to a desired angle, then apply heat-shrink to insulate.

you could wrap bare wire around the pin and apply an empty header connector to hold the wrapped wire in place.

this! I sorta considered this originally but thought it would be poor form for some reason. I actually stopped sanding the plastic to make sure the crimped part of the connector wasn't vivisible.

You should be able to pop the crimp out of the individual connector, look for the catch, push it in and slide the crimp up out of the shell. Then you can bend or otherwise modify the crimp to fit the available height and cover with heat shrink afterwards, the heatshrink doesn't look bad at all.

[bkenobi]

I removed the plastic jumper housing from both connectors, slipped a length of heat shrink on, bent the metal of the connector to 90 degrees, and hit it with a heat gun. The result is perfect. I can now close the case with the wires running through the slot in the case per design.

One other quick question. I want to connect this to a relay and have it control the GPIO logic on/off where the default will be off and the relay on state would be on. I understand that if I connect the relay to GPIO25 and ground with a pull-up resistor, the default will be high/on/true and the relay on state will be low/off/false. To get the logic I want, would I connect the relay to GPIO25 and 3.3v with a pull-down internal resistor?

[BMS Doug]

I removed the plastic jumper housing from both connectors, slipped a length of heat shrink on, bent the metal of the connector to 90 degrees, and hit it with a heat gun. The result is perfect. I can now close the case with the wires running through the slot in the case per design.

I'm glad that worked for you.

One other quick question. I want to connect this to a relay and have it control the GPIO logic on/off where the default will be off and the relay on state would be on. I understand that if I connect the relay to GPIO25 and ground with a pull-up resistor, the default will be high/on/true and the relay on state will be low/off/false. To get the logic I want, would I connect the relay to GPIO25 and 3.3v with a pull-down internal resistor?

The relay board connections will depend on the exact model of relay board that you have but normally they have a VCC (+5v), Gnd and signal connection. you would keep the +5v and Gnd connections and the signal would come from (in your case) GPIO 25 with the signal either pulled up to 3v3 or pulled down to 0v depending on your requirements.

I would configure your relay for a power failure safe state: if the power to the relay board fails (relay de-energised) then the contacts will be the same as in this configuration: (GPIO On, Relay board Off).

[davidcoton]

I understand that if I connect the relay to GPIO25 and ground with a pull-up resistor, the default will be high/on/true and the relay on state will be low/off/false. To get the logic I want, would I connect the relay to GPIO25 and 3.3v with a pull-down internal resistor?

I'm not sure what you are suggesting. You certainly do not want both an internal pull-down and an external pull-up. If you want the relay contact to be OFF when the GPIO is high (and therefore the relay coil is energised), you can use a Normally Closed (NC) contact. Otherwise the relationship between the GPIO pin and the relay contact depends on the driver circuit, which must also convert the GPIO 3V3 output to the voltage needed by the relay coil. You need to think too about the power-off condition and what happens at start-up, to avoid the relay switching briefly to an unwanted state.

[bkenobi]

I must have been confusing in my last message based on the feedback, so I'll clarify/reword. Ignore the relay, as it's not being controlled by the raspi, so it doesn't exist.

I have a contact closure (button) input that I want the logic to be low when the contact is open and high when the contact is closed. I only want to use the internal pull-up or internal pull-down resistors. I believe I should connect my wires to GPIO25 and 3.3v with the internal pull-down resistor enabled. Correct?

[BMS Doug]

I must have been confusing in my last message based on the feedback, so I'll clarify/reword. Ignore the relay, as it's not being controlled by the raspi, so it doesn't exist.

I have a contact closure (button) input that I want the logic to be low when the contact is open and high when the contact is closed. I only want to use the internal pull-up or internal pull-down resistors. I believe I should connect my wires to GPIO25 and 3.3v with the internal pull-down resistor enabled. Correct?

Oh, you want to use the Pi to monitor the contact state of the relay, sorry I misunderstood.

Yes, the situation you have described should work. current limiting resistors are normally used to ensure that the GPIO won't burn out if it becomes an output for any reason (accidents do happen).