[Arm-netbook] Release of SoM board KiCAD files with 2x100 pin ARM as a stepping stone

[jm]

On Mon, 2012-12-10 at 18:37 +0000, luke.leighton wrote:
> On Mon, Dec 10, 2012 at 4:52 PM, jm <joem at martindale-electric.co.uk> wrote:
> 
> > Ideas still in the boil - but these are the ideals:
> >
> > The SoM board will have the power manager chip (and separate connector
> > for power directly into the SoM board), SDRAM, flash, uSD, RTC,
> > a micro USB or RS232 (not sure which)
> 
>  RS232.  people always want to be able to debug, but they might want
> to use the USB-OTG.

Experience sez put in an optically isolated RS232.
When a board just comes out of manufacturing or is retrieved for repair,
there is no telling what is wrong with it. The last thing you want to
do is connect it to your precious computer and blow it up.
Optical isolator will ensure nothing like that happens.
Need to use RS232 for that.
Still - not sure which is best - may be have both?


>  actually, i'd recommend putting a micro-sd on board, wiring it up to
> the one that can duplex with JTAG and RS232.  that way boot can happen
> and debug can happen (with a breakout board).
> 
>  remember to add a jumper/switch for selecting the alternative JTAG as
> well as the alternative boot.

Good idea! Micro slide switch to select boot options.