Page 1 of 1

Pi zero connections

Posted: Thu Dec 31, 2015 12:22 pm
by Mayuresh
Hi Guys,
I have seen many pi zero pictures, and noticed on the back of Pi zero there are few non soldered connections. Is there any documents describing the pin names or GPIO or port mapping. I am not lucky enough to grab one as they are Out of Stock :( .But when I get one :( don't want to waste time thinking about ideas ;).
Thanks
M :)

Re: Pi zero connections

Posted: Thu Dec 31, 2015 6:12 pm
by Shoka
It has the same GPIO header as the other Pi's, just no connector soldered to the PCB.

The existing documentation for the 40 pin header on the the Pi2 B and Pi B+ and Pi A+ apply.

Re: Pi zero connections

Posted: Fri Jan 01, 2016 12:06 am
by Jim Manley
In addition to the 40-pin GPIO connector solder pads, there are a pair of solder pads to allow the Zero to be rebooted when connected momentarily, and a pair for the NTSC/PAL composite video output available on all Pi models. So, it is possible to solder to those latter two pads a thin 75-ohm coaxial cable that has a male or female RCA style connector (usually yellow in color). That would allow connecting an older technology 4:3 composite monitor or TV, although at much lower resolution than the HDMI HDTV output. It's really only suitable for viewing video, graphics, and perhaps kiosk-style web pages, as text is difficult to read unless the typeface size can be made very large. There are some other contact points on the board, but they're not useful to end-users and are only present to help speed up automated testing during the production process.

Re: Pi zero connections

Posted: Fri Jan 01, 2016 12:12 am
by DougieLawson
Most of those non-soldered connectors are used for board testing in the factory and aren't useful for the average user. There's a couple of through board holes for the RUN header and a couple for analog video. Then there's the standard GPIOs with the A+/B+/2B layout. There's also a couple under the USB (data) connector that have the USB D+ & D- signals.

Re: Pi zero connections

Posted: Fri Jan 01, 2016 9:08 am
by gordon77
Anyone made a list of them to identify them?

Re: Pi zero connections

Posted: Sat Jan 02, 2016 1:54 am
by Jim Manley
gordon77 wrote:Anyone made a list of them to identify them?
Sure ... 1, 2, 3, 4, 5 ... :lol:
They're just test points that make it mechanically easier to make connection with the testing rig, rather than stressing the connectors. You can get the same access through the micro-USB, mini-HDMI, GPIO, composite video, and reset connectors and solder pads.

Re: Pi zero connections

Posted: Sat Jan 02, 2016 5:42 pm
by Killertechno
May I power Pi zero from 40 pin connector instead USB?

Re: Pi zero connections

Posted: Sat Jan 02, 2016 5:47 pm
by rpdom
Killertechno wrote:May I power Pi zero from 40 pin connector instead USB?
Yes. Use any GND pin and either of the 5V pins.

Re: Pi zero connections

Posted: Sat Jan 02, 2016 6:33 pm
by hippy
gordon77 wrote:Anyone made a list of them to identify them?
No idea if correct or complete ( and the site has nothing to do with me ) ...
http://hackers.gallery/841/misc/raspber ... ad-probing

Re: Pi zero connections

Posted: Sat Jan 02, 2016 7:31 pm
by gordon77
hippy wrote:
gordon77 wrote:Anyone made a list of them to identify them?
No idea if correct or complete ( and the site has nothing to do with me ) ...
http://hackers.gallery/841/misc/raspberry-pi-zero-pad-probing
Thanks.

Re: Pi zero connections

Posted: Sat Jan 02, 2016 9:50 pm
by Jim Manley
The B+/2B test points were reported in viewtopic.php?f=28&t=89522 as:

PP1 5V from micro-USB
PP2 5V from micro-USB
PP3 GND
PP4 GND
PP5 GND
PP6 GND
PP7 5V after polyfuse
PP8 3V3
PP9 1V8
PP10 Goes from 3V3 to 2V on brownout
PP11 DAC_2V5 (for composite video DAC)
PP12 AUD_2V5 (for PWM audio drivers)
PP13 Goes from 3V3 to 2V on ACT activity
PP14 SD_CLK
PP15 SD_CMD
PP16 SD_DAT0
PP17 SD_DAT1
PP18 SD_DAT2
PP19 SD_DAT13
PP20 H5V
PP21 RUN signal (reset)
PP22 Goes from 3V3 to 2V on activity of green (link) ethernet jack LED
PP23 Goes from 3V3 to 2V on activity of yellow (speed) ethernet jack LED
PP24 COMPVID
PP25 AUDIO_L
PP26 AUDI_R
PP27 VBUS (USB 5V power)
PP28 ETH_CLK (25.000 MHz)
PP29 VC_TMS
PP30 VC_TRST_N
PP31 VC_CLK
PP32 VC_TDI
PP33 VC_TDO
PP34 GND
PP35 GPIO6 of LAN9514
PP36 GPIO7 of LAN9514
PP37 CAM_GPIO0
PP38 CAM_GPIO1
PP39 SCL0
PP40 SDA0

None of these test points has ever been documented to be useful for anything that isn't already provided via the I/O connectors where they're duplicated. Of what possible use are the Ethernet clock, GPIOs for the LAN9514 or CSI, or VC_TMS, VC_TRST_N, VC_CLK, VC_TDI, VC_TDO, etc., especially where the associated software isn't accessible at the source level that runs at the binary level on the BCM-2835/6? As the supermarket tabloid "The National Enquirer" states in its ads, "Enquiring minds want to know!" :lol:

Re: Pi zero connections

Posted: Mon Jan 04, 2016 3:04 am
by jasoncampbell4
Jim Manley wrote:In addition to the 40-pin GPIO connector solder pads, there are a pair of solder pads to allow the Zero to be rebooted when connected momentarily, and a pair for the NTSC/PAL composite video output available on all Pi models. So, it is possible to solder to those latter two pads a thin 75-ohm coaxial cable that has a male or female RCA style connector (usually yellow in color). That would allow connecting an older technology 4:3 composite monitor or TV, although at much lower resolution than the HDMI HDTV output. It's really only suitable for viewing video, graphics, and perhaps kiosk-style web pages, as text is difficult to read unless the typeface size can be made very large.

If I start a new thread later today would you be willing to guide me on this aspect? I have cables (I think) but before I start messing about I’d like to make sure. I’ll post some links to images of what I have so you can just confirm I have the idea? It’s for a simple rolling digital kiosk type advertising board so the resolution isn’t likely to be a problem- I’ll be using a Pi Zero. Sorry If I just hijacked a thread.