Enlightenment
Posts: 34
Joined: Wed Aug 24, 2011 10:16 pm

Re: What GPIO connector does everyone plan to install?

Wed Feb 29, 2012 3:12 am

Since the RPi is suppose to be shipping without a GPIO connector, what type of connector does everyone plan to install on the Raspberry Pi?

1) Installed on Top or Bottom?

2) Male Pin Header or Female Socket Header?

3) Straight or Right-Angle?

4) For Male, normal pin header or shrouded keyed connector (that will accept an IDC ribbon cable, similar to ARM JTAG connector)?

5) If none of the above, then describe.

Here are some examples that have photos.

http://en.wikipedia.org/wiki/Pin_header

http://www.samtec.com/ProductI.....series=TSW

http://www.samtec.com/ProductI.....series=SSQ

http://www.samtec.com/ProductI.....series=TSS

fireraisr
Posts: 81
Joined: Wed Nov 23, 2011 2:34 am

Re: What GPIO connector does everyone plan to install?

Sat Mar 03, 2012 2:28 am

None. I'm using an arduino to interface to my projects. GPIO won't do what I need it to do alone and I'd rather not have to fiddle with a gert board.

error404
Posts: 351
Joined: Wed Dec 21, 2011 11:49 pm

Re: What GPIO connector does everyone plan to install?

Sat Mar 03, 2012 8:41 am

fireraisr said:


None. I'm using an arduino to interface to my projects. GPIO won't do what I need it to do alone and I'd rather not have to fiddle with a gert board.


So how are you going to connect it to your Pi?

I'll probably go with a female pin header. Easier for prototyping.

User avatar
rurwin
Forum Moderator
Forum Moderator
Posts: 4258
Joined: Mon Jan 09, 2012 3:16 pm
Contact: Website

Re: What GPIO connector does everyone plan to install?

Sat Mar 03, 2012 10:05 am

Female pin-header on top of the board

Reason 1:

For school use it would be better to use a female socket to prevent pins getting bent or shorted. At first sight ribbon-cable plugs with pins are difficult to find and expensive, but a male-male gender-bender is very cheap and easy to find. A female-female gender-bender is a length of ribbon cable.

If an accessory expects a connector on the bottom and it is on the top (or vice-versa), then a length of ribbon cable can be used, with gender-benders as required.

Reason 2:

Consider the situation where an accessory is expecting to be plugged directly into the RPi, but the wrong gender connector is installed. If both are female, then a male-male gender-changer can be used. But if they are both male, you would need a ribbon-cable, and the boards would not be tied together.

Keying:

A male shrouded header is keyed so cables cannot be connected backwards. In fact it is easy to find a cable with no, or incorrect, keying. There are N/C pins on the GPIO connector. They should be blocked on the female socket and the pins removed on the male plugs. That then provides fool-proof keying.

Conclusion:

Standardise on a Female pin header on top of the board with N/C connections blocked.  Any variation can be accommodated with a suitable collection of adaptors.

Avoid connectors on the bottom of the board as they would foul many case designs.

arm2
Posts: 253
Joined: Thu Dec 15, 2011 3:46 pm

Re: What GPIO connector does everyone plan to install?

Sat Mar 03, 2012 10:19 am

I've spent a lot of time researching this, I have a few of the relevant connectors in stock as a carry over from the BBC Micro which used a 26way 0.1" shrouded pins for its Parallel printer port. I've ordered a number of other types and will photograph them all in various mock up use's next week.

Female pin headers are o.k. if you plugging in say a Real Time Clock using pins on a PCB but you can't plug a cable in as it will foul on the Video RCA socket. I have some of that type of connectors in stock and you can hack saw various parts of it away to make it fit but that is literally a hack.

In previous threads people with education in mind have expressed a preference for mounting a socket on the PCB, but with all the photo's showing pins, a lot of people will assume pins.

My suggested solution is 'shrouded pins' (As shown in the lower of the two photos on your wikipedia link), the downside to that is they cost about 2GBP more than pins even at 1000+ quantity. I'm looking to find a cheaper source but from sourcing other similair parts this month, they are likely to be on 6-8 weeek lead time and 1000+ minimum  order so if going to be investing 2,000+GBP in one connector I need to know we will be able to sell them!

arm2
Posts: 253
Joined: Thu Dec 15, 2011 3:46 pm

Re: What GPIO connector does everyone plan to install?

Sat Mar 03, 2012 3:16 pm

I should have said ...My suggested solution is shrouded pins... "on the top of the RPi." and:

If you are planning on using a GERT Board then AIUI it expects a socket to be soldered to the underside of the RPi so that it plugs into pins on top of the GERT board.

I am also sourcing some pass through sockets. The photos I will take should demonstrate that better than I can explain.

User avatar
rurwin
Forum Moderator
Forum Moderator
Posts: 4258
Joined: Mon Jan 09, 2012 3:16 pm
Contact: Website

Re: What GPIO connector does everyone plan to install?

Sat Mar 03, 2012 6:22 pm

But most cases that will be produced will expect that there is nothing on the underside of the board that projects further than the SD card socket.

So if you fit a socket on the underside of the board then the board will no longer fit into most available cases.

However the USB socket projects further than that, so there is adequate clearance on the top of the board.

hippy
Posts: 6509
Joined: Fri Sep 09, 2011 10:34 pm
Location: UK

Re: What GPIO connector does everyone plan to install?

Sat Mar 03, 2012 6:24 pm

The answer really depends on what you are planning to connect the R-Pi to. It seems pointless to me to fit anything if you don't have any idea of what connection you would best require some time in the future.

If I were forced to give an answer I'd say female headers. And, if hoping to produce a defcato standard, then I'd recommend that.

Another alternative, for general purpose, experimenting use by electronics enthusiasts, is to fit turned pin SIL sockets and then just plug single core wire into those. That makes it easy to link an R-Pi into breadboard.

texy
Forum Moderator
Forum Moderator
Posts: 5160
Joined: Sat Mar 03, 2012 10:59 am
Location: Berkshire, England

Re: What GPIO connector does everyone plan to install?

Sat Mar 03, 2012 6:26 pm

Where is the information found regarding the lack of the gpio connector?

If the intention is for user to solder there own connector, then how does this effect warranty (assuming there is any warranty1!).

T.
Various male/female 40- and 26-way GPIO header for sale here ( IDEAL FOR YOUR PiZero ):
https://www.raspberrypi.org/forums/viewtopic.php?f=93&t=147682#p971555

greengarbedheroes
Posts: 5
Joined: Sat Mar 03, 2012 4:25 pm

Re: What GPIO connector does everyone plan to install?

Sat Mar 03, 2012 6:28 pm

May I ask what a GPIO connector actually is? I know nothing about all this electronicy stuff.

greengarbedheroes
Posts: 5
Joined: Sat Mar 03, 2012 4:25 pm

Re: What GPIO connector does everyone plan to install?

Sat Mar 03, 2012 6:28 pm

May I ask what a GPIO connector actually is? I know nothing about all this electronicy stuff.

clacktronics
Posts: 60
Joined: Sat Mar 03, 2012 6:07 pm
Location: London
Contact: Website

Re: What GPIO connector does everyone plan to install?

Sat Mar 03, 2012 7:07 pm

http://en.wikipedia.org/wiki/G.....put/Output

see the WIKI

http://elinux.org/RPi_Low-leve.....eripherals

information about the Broadcom GPIO is here ( section 6 )

www.raspberrypi.org/wp-content/.../BCM2 ... herals.pdf

It is basically an expansion connector, it could be as simple as a button to control some function or it could be something more complex like a display or a camera input
My Kickstarter for a analogue AV out - kck.st/1SuGDvV

greengarbedheroes
Posts: 5
Joined: Sat Mar 03, 2012 4:25 pm

Re: What GPIO connector does everyone plan to install?

Sat Mar 03, 2012 7:22 pm

Ok, is it necessary for the Raspberry Pi?

greengarbedheroes
Posts: 5
Joined: Sat Mar 03, 2012 4:25 pm

Re: What GPIO connector does everyone plan to install?

Sat Mar 03, 2012 7:22 pm

Ok, is it necessary for the Raspberry Pi?

drgeoff
Posts: 10087
Joined: Wed Jan 25, 2012 6:39 pm

Re: What GPIO connector does everyone plan to install?

Sat Mar 03, 2012 7:26 pm

greengarbedheroes said:


Ok, is it necessary for the Raspberry Pi?


Is a towbar necessary on a car?

(Answer to both questions:  It depends.)

arm2
Posts: 253
Joined: Thu Dec 15, 2011 3:46 pm

Re: What GPIO connector does everyone plan to install?

Sat Mar 03, 2012 8:30 pm

hippy said:



If I were forced to give an answer I'd say female headers. And, if hoping to produce a defcato standard, then I'd recommend that.


On the top or the bottom?

If the top how will you plug into with a cable as the RCA socket fouls?

error404
Posts: 351
Joined: Wed Dec 21, 2011 11:49 pm

Re: What GPIO connector does everyone plan to install?

Thu Mar 08, 2012 7:57 pm

So buried in the comments on the hiccup announcement Gert says:


As we are on GPIO headers and soldering :
I have seen a first production batch board. It had the GPIO connector in place (Male at the top).



I guess that sets a standard, though I can't be the only one going WTF?! We've been told for months that no header would be supplied. This can't have been accidental (he also says it's on the BOM). So, uhm… thanks guys?

Male also seems a bad choice to me.

Really glad I held off on designing any kind of hardware until I get a board.

User avatar
rurwin
Forum Moderator
Forum Moderator
Posts: 4258
Joined: Mon Jan 09, 2012 3:16 pm
Contact: Website

Re: What GPIO connector does everyone plan to install?

Thu Mar 08, 2012 8:26 pm

If you check back, I think you will find that almost all of that was us telling each other. The only "definitive" remark I remember reading was Gert giving a report of something he understood to be the case.

I wonder if the three connectors were variable in case of costing problems. Not fitting them might save up to 10% of the cost of the boards, although probably less.

Gert does go on to say, in the post you reference, that the connectors may only be fitted to the first 2,000 boards.

Even so, it does probably set the standard.

Return to “General discussion”