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GPIO confusion

Posted: 17 Nov 2014 21:34
by RajenK
Hi all,

Just got my RaZberry and I'm a bit confused on how to hook it up. I have a Raspberry Pi B+ and the manual states it should hook up to GPIO 17-26, sounds easy enough. The pictures I find online, however, seem to contradict the pin out diagram on the official Raspberry site for the Model B:

http://www.raspberrypi.org/documentation/usage/gpio/

Image

According to the diagram, GPIO 17-26 should be closest to the Video RCA plug, but all the pictures seem to put it on the other side, which would be 1-10 (which doesn't make sense, as that's 2x 5v, 1x 3.3v, 2x GND and 5x GPIO).

Can someone please clear up the confusion for me? Thanks!

Re: GPIO confusion

Posted: 17 Nov 2014 22:11
by RajenK
To make matters even more confusing, the image on the included instruction shows a Model B+ with the RaZberry board connected to the far edge as well:

Image

That also seems to be the same 2x 5v, 1x 3.3v, 2x GND, 5x GPIO combo (http://pi4j.com/pins/model-b-plus.html).

Re: GPIO confusion

Posted: 17 Nov 2014 22:24
by pofs
Where did you read about GPIO 17-26 pins? I've looked over pdfs on the site, and they never mention pin numbers.

You should hook it up as shown in the pictures (pins 1-10).

Re: GPIO confusion

Posted: 17 Nov 2014 22:27
by RajenK
pofs wrote:Where did you read about GPIO 17-26 pins? I've looked over pdfs on the site, and they never mention pin numbers.

You should hook it up as shown in the pictures (pins 1-10).
Check out the picture I took of the instruction that came with the board (second post): "(it uses the GPIO Pins 17-26)". So, that's incorrect and it indeed hooks up to the 2x 5v, 1x 3.3v, 2x GND, 5x GPIO combination?

Re: GPIO confusion

Posted: 17 Nov 2014 22:52
by pz1
Well the confusion may arise from the fact that the functionality of the pins are programmable. (See http://wiringpi.com/pins/special-pin-functions/) So that may lead to misleading naming conventions on the edge connector. Actually GPIO X is defined on the SOC chip, and may be mapped to a specific pin on the edge connectors.
It is very confusing indeed. One probably has to be of British origin to really understand and appreciate :mrgreen:
Took me quite a while when I made thehttp://razberry.zwave.me/index.php?id=3

Re: GPIO confusion

Posted: 17 Nov 2014 23:36
by RajenK
pz1 wrote:Well the confusion may arise from the fact that the functionality of the pins are programmable. (See http://wiringpi.com/pins/special-pin-functions/) So that may lead to misleading naming conventions on the edge connector. Actually GPIO X is defined on the SOC chip, and may be mapped to a specific pin on the edge connectors.
It is very confusing indeed. One probably has to be of British origin to really understand and appreciate :mrgreen:
Took me quite a while when I made thehttp://razberry.zwave.me/index.php?id=3
Interesting :) Weird that it states this by default, though. Either way I got it working now. Thanks!

Re: GPIO confusion

Posted: 19 Nov 2014 17:27
by PoltoS
Thanks for the feedback, we will fix it in the PDF coming with the device

Re: GPIO confusion

Posted: 29 Nov 2014 01:21
by OneFastt997
Interesting. So the board should be plugged in on the opposite end shown in the documentation?

I tried it both ways and can't get it to work either way but I don't want to troubleshoot further until I know which one is right.

Re: GPIO confusion

Posted: 29 Nov 2014 10:20
by pz1
OneFastt997 wrote:I tried it both ways and can't get it to work either way but I don't want to troubleshoot further until I know which one is right.
The position as in the picture is correct