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

[jm]

On Mon, 2012-12-10 at 22:30 +0100, Alejandro Mery wrote:
> On 10 December 2012 21:46, jm <joem at martindale-electric.co.uk> wrote:
> > 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.
> 
> not rs232, the native ttl uart0 of the SoC

4 pads tx,rx,gnd,+ve for UART0.

> > Still - not sure which is best - may be have both?
> 
> I believe it's wrong to put the OTG connector in the SoM itself, it
> will limit the capabilities of the device where you plan to connect
> this module

Same here - too bulky - may be leave the solder pads in with connections
to it using 0R resistors, but not fit it. The 0R allows for signals to
be routed to the mboard or to onboard smt usb socket as needed.
USB-OTG too useful not to have.