Mattylad
Posts: 98
Joined: Tue Jan 17, 2012 9:59 pm

Circuit diagram for the latest model?

Wed Sep 26, 2012 7:18 pm

Hi, the previous version had its circuit diagram released - has the latest model had its diagram released?

I am struggling to find it if it has.

Cheers.
M.

W. H. Heydt
Posts: 11672
Joined: Fri Mar 09, 2012 7:36 pm
Location: Vallejo, CA (US)

Re: Circuit diagram for the latest model?

Wed Sep 26, 2012 8:33 pm

Considering what the changes are...it should be easy enough to derive the new one from the old one...remove F1, F2 and D14 (bridging the connections) and separate the 1.8v rails on the SoC and USB controller from each other.

User avatar
jojopi
Posts: 3146
Joined: Tue Oct 11, 2011 8:38 pm

Re: Circuit diagram for the latest model?

Wed Sep 26, 2012 8:51 pm

W. H. Heydt wrote:remove F1, F2 and D14 (bridging the connections) and separate the 1.8v rails on the SoC and USB controller from each other.
… add C97, D18, and P6; remove R3..R10 and add P5; swap GPIO21 and 27; swap GPIO0,1 and 2,3; connect D14 to +5V0_HDMI instead of +3V3.

Mattylad
Posts: 98
Joined: Tue Jan 17, 2012 9:59 pm

Re: Circuit diagram for the latest model?

Wed Sep 26, 2012 8:57 pm

OK cheers. (I take it that's a no then lol).

Do you know if anyone ever made a bill of materials for it?

User avatar
excollier
Posts: 194
Joined: Wed Sep 12, 2012 8:17 am

Re: Circuit diagram for the latest model?

Thu Sep 27, 2012 7:36 am

Thinking of becoming a Raspberry Pi-rate?
Sorry, couldn't stop that one.

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 25433
Joined: Sat Jul 30, 2011 7:41 pm

Re: Circuit diagram for the latest model?

Thu Sep 27, 2012 8:53 am

Mattylad wrote:OK cheers. (I take it that's a no then lol).

Do you know if anyone ever made a bill of materials for it?
Pretty easy to do so - not that many parts!

However, making one is not easy as you would need to source the SoC which isn't possible is small quantities.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed. Here's an example...
“I own the world’s worst thesaurus. Not only is it awful, it’s awful."

User avatar
penguintutor
Posts: 378
Joined: Tue May 08, 2012 9:11 am
Location: UK
Contact: Website

Re: Circuit diagram for the latest model?

Thu Sep 27, 2012 10:13 am

Pretty easy to do so - not that many parts!
Not many parts - but pretty tricky for the 6 layer PCB with blind micro vias to get all the HD interconnects.

If you've not already seen I'd recommend a read of:

http://www.wired.com/opinion/2012/09/ra ... -sell-out/

It's possible to make a Raspberry Pi compatible, but the cost saving would be fairly small to the end user so unlikely to make sufficient sales - why save £3 on a "rip-off" when the real thing is only £30.

A more practical thing would be to create a more specific version for a specific commercial project dropping any superfluous components. But then if you have the capability to design the PCB required you probably don't need to copy the design from the Raspberry Pi (thinking of dedicated Linux based machines already on the market - set-top-boxes / NAS / Routers etc.)

Being able to see the Schematic can have advantages and whilst it's possible to work it out from the description of the changes it easier to see directly on the diagram.

AFAIK there is no updated schematic publicly available yet.

I find the schematic to be quite useful. It's been interesting to see where the fuses are in relation to the various connectors - eg. micro-USB before 1.1A fuse; GPIO after that fuse; USB through the 140mA fuses (early versions only), therefore you can see that if you try and power external components through from the GPIO (using micro-USB as source) then you are still limited to 1.1A - whereas if you apply your own power source to an external circuit and feed that supply back to the Pi then you can overcome that limitation.

jamesh
Raspberry Pi Engineer & Forum Moderator
Raspberry Pi Engineer & Forum Moderator
Posts: 25433
Joined: Sat Jul 30, 2011 7:41 pm

Re: Circuit diagram for the latest model?

Thu Sep 27, 2012 11:34 am

penguintutor wrote:
Pretty easy to do so - not that many parts!
Not many parts - but pretty tricky for the 6 layer PCB with blind micro vias to get all the HD interconnects.

If you've not already seen I'd recommend a read of:

http://www.wired.com/opinion/2012/09/ra ... -sell-out/

It's possible to make a Raspberry Pi compatible, but the cost saving would be fairly small to the end user so unlikely to make sufficient sales - why save £3 on a "rip-off" when the real thing is only £30.

A more practical thing would be to create a more specific version for a specific commercial project dropping any superfluous components. But then if you have the capability to design the PCB required you probably don't need to copy the design from the Raspberry Pi (thinking of dedicated Linux based machines already on the market - set-top-boxes / NAS / Routers etc.)

Being able to see the Schematic can have advantages and whilst it's possible to work it out from the description of the changes it easier to see directly on the diagram.

AFAIK there is no updated schematic publicly available yet.

I find the schematic to be quite useful. It's been interesting to see where the fuses are in relation to the various connectors - eg. micro-USB before 1.1A fuse; GPIO after that fuse; USB through the 140mA fuses (early versions only), therefore you can see that if you try and power external components through from the GPIO (using micro-USB as source) then you are still limited to 1.1A - whereas if you apply your own power source to an external circuit and feed that supply back to the Pi then you can overcome that limitation.
The pretty easy was in relation to the BOM, not the circuit diagram.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed. Here's an example...
“I own the world’s worst thesaurus. Not only is it awful, it’s awful."

Mattylad
Posts: 98
Joined: Tue Jan 17, 2012 9:59 pm

Re: Circuit diagram for the latest model?

Thu Sep 27, 2012 5:07 pm

I doubt I would ever get around to laying out the whole board, but doing the schematic can be fun, should only take me a couple of days including making all the parts etc.

Board layout is something I have done for 20 years so messing around with stuff like the schematic etc is the sort of little project that's easy peasy for me. In reality I just like to see how the guts of it connect up.
Cheers for the reply.

User avatar
liz
Raspberry Pi Foundation Employee & Forum Moderator
Raspberry Pi Foundation Employee & Forum Moderator
Posts: 5203
Joined: Thu Jul 28, 2011 7:22 pm
Contact: Website

Re: Circuit diagram for the latest model?

Fri Sep 28, 2012 3:00 am

We'll definitely be releasing a circuit diagram for the rev2 board - and soon. We've a few things to square away before we can, but it's definitely coming up real soon now.
Director of Communications, Raspberry Pi

User avatar
jbeale
Posts: 3581
Joined: Tue Nov 22, 2011 11:51 pm
Contact: Website

Re: Circuit diagram for the latest model?

Fri Sep 28, 2012 5:15 am

So there you have it... sounds like it will officially be Real Soon Now.

Mattylad
Posts: 98
Joined: Tue Jan 17, 2012 9:59 pm

Re: Circuit diagram for the latest model?

Fri Sep 28, 2012 6:35 am

Cheers Liz.

Return to “General discussion”