[Arm-netbook] EOMA Micro Engineering Board case built

[joem]

On Mon, 2013-08-12 at 10:05 +0100, luke.leighton wrote:
> On Mon, Aug 12, 2013 at 9:34 AM, joem <joem at martindale-electric.co.uk> wrote:
> > On Mon, 2013-08-12 at 00:43 +0100, luke.leighton wrote:
> >> awesome joe - i've linked it here:
> >> http://rhombus-tech.net/community_ideas/micro_engineering_board/
> >>
> >> btw remember you'll need to do some mods to the MEB to make it useable.
> >
> > No problem - do you have a pdf of circuit diagram?
> 
>  http://hands.com/~lkcl/eoma/meb/MEB.pdf

Grumble mumble.... 

1. The PTC R1 is rated 0.23R. If 1V flows with D1 taken
out, the loss is 0.23V. And its designed to trip at 1.3A.
Not a good idea with SATA and stuff connected.
Short R1 I recommend.

2. D2 is rated 5.1V and is too ambitious if D1 is shorted.
Remove D2 recommend.

(Items such as PTC, D1, D2 should placed before a regulator
 and at least 2V above the regulator output voltage.)

Looking at these:
http://rhombus-tech.net/community_ideas/micro_engineering_board/

3. REMOVE R2 *BEFORE* EVER POWERING UP!!!!!!!!!!

4. Put a wire between pin 1 and pin 11 on the underside of the PCB, on
J4. The datasheet for the connector is http://media.digikey.com/pdf/Data
%20Sheets/Sullins%20PDFs/SMJ001-S88N-DS-11.pdf

5. Short D1 - good idea, and use regulated 5V power supply - current
requirement is 2A ?

6. I assume the pull up resistors for I2C is inside the EOMA?