[Arm-netbook] update to EOMA68 specification [was Re: 5" LCD resolution 800x480 working for EOMA but color problems may exist because of miswire]

[joem]

> Hmmmppp...... The is another outstanding issue that needs resolving
> before the next batch goes into production - this time to do with the RS232 RX line.
> When connected, the entire board is able to power up through the RX line.
> The cubieboard1,2 and iteaduino plus and EOMA-A20 boards all have same defect
> because I assume all of them were designed and tested by the same engineering
> team from Wits with no peer review input onto the process.

|  ... well, the schematics for the EVB and also the schematics for the
|GPL-licensed EOMA68-A10/20 CPU Card have been publicly available for
|nearly two years.  unfortunately we've not had you around until
|recently joe... *rueful*...

> If you are doing another batch, make sure the CPU board RX line doesn't
> power up the entire board through that line.

| not going to happen, for exactly the same reason that the RGB/TTL
|lines are not going to be modified: it's too late.  the PCB design
|went out to the factory over two months ago when the first 30 samples
|were made, and the gerbers cannot now be changed.  a) it would make
|the factories nervous (no way we're doing that) b) someone needs to

Don't believe in such things. Most good factories are only too glad
to help down to the wire. I've changed stuff after 1st day of production.
The most likely thing they do is charge a little extra or amortize
it into the next production run. Good companies know it is all part of
the deal when first starting up production.

|come up with another $2k (or so) to do another round of samples c) we
|would need to delay production (no way we're doing that, not right
|before christmas) d) the PCB factory is *far* too busy to redo the
|gerbers right just before christmas production.
|
| so - no. no changes to the CPU Card.

If its gone to production, it not end of world.
Just more revisions are due next batch.
The revision to fix RX line problem will likely be transparent
to end user.

| instead, the spec therefore has to reflect that and require that the
|I/O boards add in suitable compensating circuitry instead.  none of
|the I/O boards have gone into production yet, so that's the only
|remaining place where the flexibility and changes can go.

That perfectly OK - as the end user doesn't loose
anything.

Learn from this - always make in batches of 10 to iron out problems.
And keep making them until done. Also have them for sale
for anyone that wants alpha hardware. Most hardened developers only want
the alpha hardware. You can always refund them if it don't work,
or send them free working hardware to compensate them later.