Re: [Emc-users] r-pi<->7i90 cable update

[Bertho Stultiens]

On 12/18/2016 09:13 PM, Gene Heskett wrote:
> Update:  In an effort to identify all the grounds available on the pi's 
> 40 pin gpio header, I went the their site at
> 
> 
> 
> Which they claim also aplies to the 3b's, and found that there are 2 std 
> ways of numbering the pins!!!  Such idiocy should cause the author of 
> such to be first against the wall, but its done and published and I 
> can't change it.
> 
> The signals don't physically move, but the pins aren't numbered in the 
> usual
> 2  4  6  8  10 12 etc to 40
> 1  3  5  7  9  11 etc to 39 sequence I've been looking at since the first 
> dil connector I ever saw on a scsi-ii cable in the 80's.
> 
> But this web page does not get to using that common sense pin numbering 
> sequence until page 4 of the printed copy! This has to have an excedrin 
> headache number defined someplace...
> 
> So my question is, which numbering sequence is in use for the published 
> SPI interconnection drawings I am working from? I *think* I got this 
> printout from Matsche.


The first image:

https://www.raspberrypi.org/documentation/usage/gpio-plus-and-raspi2/images/gpio-numbers-pi2.png

These are the GPIO numbers connected to the pins. The numbers are not
pin header numbers.


The second image is in appendix 1 under the header "Physical numbering":

https://www.raspberrypi.org/documentation/usage/gpio-plus-and-raspi2/images/physical-pin-numbers.png

The physical numbering is exactly as you would expect.

If you want both numbering schemes and the signal, then you can, for
example, look at:
 
https://www.element14.com/community/servlet/JiveServlet/previewBody/68203-102-6-294412/GPIO.png


-- 
Greetings Bertho

(disclaimers are disclaimed)

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Re: [Emc-users] r-pi<->7i90 cable update

[W. Martinjak]

On 2016-12-18 21:13, Gene Heskett wrote:
> Update:  In an effort to identify all the grounds available on the pi's 
> 40 pin gpio header, I went the their site at
>
> 
>
> Which they claim also aplies to the 3b's, and found that there are 2 std 
> ways of numbering the pins!!!  Such idiocy should cause the author of 
> such to be first against the wall, but its done and published and I 
> can't change it.

Gene,

it's already there as attachment since almost 2 month!

https://forum.linuxcnc.org/media/kunena/attachments/18479/RP2_Pinout.png
https://forum.linuxcnc.org/27-driver-boards/31753-raspberry-pi-and-mesa-7i90-spi-works-well#82070

-- 
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nur ihre Gegner sterben nach und nach"

Max Planck


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Re: [Emc-users] r-pi<->7i90 cable update

[Gene Heskett]

On Saturday 17 December 2016 19:10:45 Gene Heskett wrote:

> Greetings all;
>
> Not in a huge hurry to get this cable done as the replacement R-Pi's
> haven't arrived yet, but I do have the cables meeting & soldered on a
> smallish piece of perfboard as of 2 hours ago. Still to be made up are
> as many grounds as I can find on the r-pi & buss them out to the 8
> grounds available in the 7i90's 26 pin connector.  And the 3 source
> terminating R's near the 40 pin connector are still on the bench near
> the cable.
>
> I made a trip to Bridgeport's Radio Shack and got some 82 ohm 1/8 watt
> R's for the terminators. Along with 2 rolls of their 2% silver bearing
> solder, and a couple bags of ring lugs to make up a star ground system
> in the electronics box. That particular solder can be cooked as low as
> 315C, so the insulation on the ribbon cable is not noticeably damaged
> from the soldering heat.  Beats the lead-free crap like a white
> mouthed mule since the lead free needs 385C or more, prefereably lots
> more, so you have to run the heat up, and re-tin the iron before every
> joint.
>
> Progress, but you might have to call a surveyor & set stakes to
> measure it by. :) Not much use pushing until I have the R-Pi's and the
> x motors PSU(s).
>
> Have a Merry Christmas everybody.
>
> Cheers, Gene Heskett

Update:  In an effort to identify all the grounds available on the pi's 
40 pin gpio header, I went the their site at



Which they claim also aplies to the 3b's, and found that there are 2 std 
ways of numbering the pins!!!  Such idiocy should cause the author of 
such to be first against the wall, but its done and published and I 
can't change it.

The signals don't physically move, but the pins aren't numbered in the 
usual
2  4  6  8  10 12 etc to 40
1  3  5  7  9  11 etc to 39 sequence I've been looking at since the first 
dil connector I ever saw on a scsi-ii cable in the 80's.

But this web page does not get to using that common sense pin numbering 
sequence until page 4 of the printed copy! This has to have an excedrin 
headache number defined someplace...

So my question is, which numbering sequence is in use for the published 
SPI interconnection drawings I am working from? I *think* I got this 
printout from Matsche.

Maybe I've mucked it up in using loose jumpers...  And since I've pulled 
all that back out, no way to check now. Except complete my cable using 
the PCB drawing from Jeff Eplers project on github. A board drawing 
which does not include the common grounds that are the target of my 
searching right now.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page 

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