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abishur
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Re: Finalised PCB design now on the front page

Wed Nov 16, 2011 5:09 pm

OH! I was looking at gert\'s response and thought \"DSI is on top of SD card\" to mean above, I\'ll update the picture in a bit!
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abishur
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Re: Finalised PCB design now on the front page

Wed Nov 16, 2011 5:19 pm

Okay try two here

[img]https://lh3.googleusercontent.com/-UCb8 ... layout.png[/img]
Click for larger version

As you can see from the labels I have no idea what\'s up there at the top right! It\'s clearly attached to the LAN9512. My only thought is that I have the USB in the wrong spot, and that\'s the USB ports... but then what would be the object I\'ve labeled as USB ports?

Edit: I suppose it\'s possible that the \"something\" is the JTAG, and what I\'ve labeled as \"JTAG\" are additions GPIO? /Edit
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AdRiley
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Re: Finalised PCB design now on the front page

Wed Nov 16, 2011 5:34 pm

I thought top right was LEDs? Think I saw a comment from Liz somewhere saying they could reduce the number of LEDS and put a mounting hole in that corner. Maybe...
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AdRiley
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Re: Finalised PCB design now on the front page

Wed Nov 16, 2011 5:38 pm

Found it. Comment on the blog from Liz:

\"There are no mounting holes in this iteration of the design. We hope to ship with some (hopefully 2) mounting holes – there are places on this board where we can fit them in, but that’ll need to wait for Pete’s return. See, for example, the top right where there are lots of leds – holes are cheaper than leds and we reckon we can get by with just 1 or 2 leds. (1 led can be on for power, and blink on and off for when it’s accessing the SD card, for example.)\"
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carlosfm
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Re: Finalised PCB design now on the front page

Wed Nov 16, 2011 5:41 pm

Correct, top right corner are resistors (top layer) and leds (bottom layer).
I would prefer to have two mounting holes, really.
One hole there and the other one on the opposite bottom corner, relocating the micro USB power plug.
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Nutmeat
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Re: Finalised PCB design now on the front page

Wed Nov 16, 2011 6:23 pm

[quote]Quote from vladhed on November 16, 2011, 00:28
Should be good for a laugh when we find out we\'re all wrong :-D :-D[/quote]
This has been one very entertaining thread.

Indeed it\'ll be good for a laugh (it is already!), but I think abishur has hit the mark, where, as has now been confirmed through cleverly \"data mining what Liz says\", something = LEDs.

Oh my, it is so incredibly dense! <sarcasm> Too bad they aren\'t selling kits so we can solder them together! </sarcasm>

Now that would be good for a laugh!

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abishur
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Re: Finalised PCB design now on the front page

Wed Nov 16, 2011 7:10 pm

Edit2: We can confidently say that this layout is most likely correct! A major thanks to Hippy for providing the basic image I used for placing the objects and to everyone else for helping refine the rest of it! /Edit2

Good Catch AdRiley! I had missed that post from Liz.

Here\'s v3 of the boardlayout (click for larger version).

[img]https://lh3.googleusercontent.com/-uO4l ... layout.png[/img]

I feel like we\'ve done a fairly good job taking the little bits they\'ve dropped and working out the board. At the very least I\'m confident on the SOC and LAN9512 (duh). Gert told us the locations of the CSI/DSI (and indirectly the HDMI, SD slot, and LAN as well). Liz told us the location of the LEDs. The USB ports are identified by the process of elimination (it has to be connected to the LAN9512)

The only things we haven\'t had direct confirmation on is the PSU (whose location I\'m rather confident about), JTAG, GPIO, Audio, and RCA, and of those the only thing that wouldn\'t surprise me to find out we messed up on is the Audio and RCA locations.

Edit: Thanks to everyone for helping to make the above layout! Take that Sherlock Holmes! /Edit
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psergiu
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Re: Finalised PCB design now on the front page

Wed Nov 16, 2011 7:24 pm

Hmmm - is the audio port a 5 pin DIN ? - this means Stereo in & out, line level ? Or that RPi is able to load games from casette tapes ? ;-)

Michael
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Re: Finalised PCB design now on the front page

Wed Nov 16, 2011 7:26 pm

[quote]Quote from abishur on November 16, 2011, 19:10
The only things we haven\'t had direct confirmation on is the PSU (whose location I\'m rather confident about), JTAG, GPIO, Audio, and RCA, and of those the only thing that wouldn\'t surprise me to find out we messed up on is the Audio and RCA locations.
[/quote]

RCA is easy to confirm by comparing to the Alpha board. Strictly speaking, I think the thing labelled PSU is actually the micro-USB power connector - the PSU circuitry extends further right than indicated to include some caps, fuse and a large diode (again, compare to the Alpha board).

We know from comments by Eben and Gert that they were looking to source a cheaper Audio connector and it looks like this one has four through-holes for connector shielding, plus four pins for the stereo jack and switch.

carlosfm
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Re: Finalised PCB design now on the front page

Wed Nov 16, 2011 7:33 pm

The RCA composite output is correct, that\'s the layout for a typical RCA PCB mount plug.
The audio out is a 3.5mm jack and it\'s also correct, there is Left, Right, Ground and unused (in this case) pins which come from two internal switch contacts (one per channel), activated when you insert/remove the jack.

abishur\'s layout above seems to be just right.
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liz
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Re: Finalised PCB design now on the front page

Wed Nov 16, 2011 7:35 pm

You guys are fantastic. We\'re very impressed!
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johnbeetem
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Re: Finalised PCB design now on the front page

Wed Nov 16, 2011 7:51 pm

[quote]Quote from Michael on November 16, 2011, 19:26
We know from comments by Eben and Gert that they were looking to source a cheaper Audio connector and it looks like this one has four through-holes for connector shielding, plus four pins for the stereo jack and switch.[/quote]

I\'m very glad to see through-hole connections for audio, video, etc. Surface mount does not stand up well to heavy use -- the connectors tear the foil right off the PCB. This is particularly true of audio where you often insert and extract plugs.

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abishur
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Re: Finalised PCB design now on the front page

Wed Nov 16, 2011 7:53 pm

Which is to say that in all likelihood that PCB is labeled correctly! (I didn\'t extend out the PSU stuff because I was just labeling the point of entry ;) ) Adding the above post to my signature!
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liz
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Re: Finalised PCB design now on the front page

Wed Nov 16, 2011 8:01 pm

Through-holes - yes, they\'re very important. We see how much plugging and unplugging of peripherals gets done in development (lovely though our devs are, they\'re not terribly gentle). Kids are likely to be even rougher in their handling of the boards, so we designed with that in mind.
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obarthelemy
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Re: Finalised PCB design now on the front page

Wed Nov 16, 2011 8:44 pm

Aren\'t the green dots through holes ? that would mean the SD needs to be rotated 90° ?

Michael
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Re: Finalised PCB design now on the front page

Wed Nov 16, 2011 8:55 pm

[quote]Quote from obarthelemy on November 16, 2011, 20:44
Aren\'t the green dots through holes ?[/quote]

I think the green dots on Ethernet, SD and HDMI are un-via\'d through-holes (through-holes that don\'t form a connection) and are for plastic locating lugs on the connectors. I think the remaining two green dots are test points.

[quote]Quote from abishur on November 16, 2011, 19:53
Which is to say that in all likelihood that PCB is labeled correctly![/quote]

Yup - didn\'t mean to imply it wasn\'t :) Wiki page updated: http://elinux.org/RaspberryPiBoard#Schematic_.2F_Layout

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abishur
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Re: Finalised PCB design now on the front page

Wed Nov 16, 2011 9:07 pm

lol, I didn\'t think you were trying to imply it was wrong, I was just happy and re-stating the obvious :P
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Michael
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Re: Finalised PCB design now on the front page

Wed Nov 16, 2011 9:20 pm

So, Liz and Gert, how about teasing us a little more by revealing the silkscreen layer or the pinouts for the connectors hippy and abishur have labelled as GPIO and JTAG? Please don\'t tell us we have to wait for Pete to return :P

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abishur
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Re: Finalised PCB design now on the front page

Wed Nov 16, 2011 9:51 pm

(Or even confirming if we really got it all right! :D )
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johnbeetem
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Re: Finalised PCB design now on the front page

Wed Nov 16, 2011 11:35 pm

[quote]Quote from Michael on November 16, 2011, 20:55
I think the green dots on Ethernet, SD and HDMI are un-via\'d through-holes (through-holes that don\'t form a connection) and are for plastic locating lugs on the connectors. I think the remaining two green dots are test points.
[/quote]

I agree the green dots on Enet, SD, and HDMI are most likely non-plated alignment holes. For some connectors they could be press-fit to help hold the connector on and to make soldering easier.

One guess for the other two green dots (one under Enet, one between RCA and Audio) is that they are mounting holes. A mounting hole between RCA and Audio is very nice since there\'s a lot of force on those connectors. The Enet hole wouldn\'t be used on a Model B, but the Enet shell itself does a pretty good job of holding a board in place.

OTOH, they\'re probably too small. So guess #2 is that they are for soldering 25 mil square ground posts for connecting silly-scope ground when debugging the board. Otherwise finding an extra ground connection can be a real pain on an SMT board.

carlosfm
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Re: Finalised PCB design now on the front page

Thu Nov 17, 2011 10:34 am

Right, there seems to be a mounting hole between the audio jack and the composite video plug.
Under the ethernet plug (front side) I think it\'s part of the fixing of the plug itself to the PCB.
I would suggest an additional fixing hole in the small empty area between the PSU and HDMI plugs, at the bottom edge of the board.
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jojopi
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Re: Finalised PCB design now on the front page

Thu Nov 17, 2011 1:16 pm

[quote]Quote from carlosfm on November 17, 2011, 10:34
Right, there seems to be a mounting hole between the audio jack and the composite video plug.
Under the ethernet plug (front side) I think it\'s part of the fixing of the plug itself to the PCB.
[/quote]

I think these are just fiducial marks to help the pick and place robot align the parts accurately. Shiny copper targets inside a dark island of missing solder-resist.

edit: There is a third under the micro-USB.

NoSuchNick
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Re: Finalised PCB design now on the front page

Sat Nov 19, 2011 8:34 pm

I was just trying to prepare a r-pi part in eagle and a question occured to me:
53.98 is a very odd measurement, are the dimensions actually 85.60mm x 53.98mm or are they 3370 mil x 2125 mil?

Asgo
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Re: Finalised PCB design now on the front page

Sat Nov 19, 2011 9:09 pm

[quote]Quote from NoSuchNick on November 19, 2011, 20:34
I was just trying to prepare a r-pi part in eagle and a question occured to me:
53.98 is a very odd measurement, are the dimensions actually 85.60mm x 53.98mm or are they 3370 mil x 2125 mil? [/quote]
The 85.60mm x 53.98mm measurement matches actually rather well the targeted credit card sized business card.

NoSuchNick
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Re: Finalised PCB design now on the front page

Sat Nov 19, 2011 9:39 pm

[quote]Quote from Asgo on November 19, 2011, 21:09
[quote]Quote from NoSuchNick on November 19, 2011, 20:34
I was just trying to prepare a r-pi part in eagle and a question occured to me:
53.98 is a very odd measurement, are the dimensions actually 85.60mm x 53.98mm or are they 3370 mil x 2125 mil? [/quote]
The 85.60mm x 53.98mm measurement matches actually rather well the targeted credit card sized business card. [/quote]
The difference between 2125 mil and 53.98mm is actually only 0.005 mm, so for all practical purposes it is negligable.
The reason I\'m wondering, is that through hole components like the GPIO headers are often defined in inches, while smd components often have spacing in \"round\" metric measurements. This is probably completly inconsequential for a board like this, but as a neat freak i like to have my headers on nice round mill coordinates, so i was just wondering if the r-pi is as obsessive compulsive as i am.

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