where to connect for extension ?

[Alessandro Sappia]

On Sat, Nov 22, 2008 at 11:46 AM, Al Johnson
<openmoko at mazikeen.demon.co.uk> wrote:
> On Friday 21 November 2008, Alessandro Sappia wrote:
>> Hi
>> Me and some friends wants to connect the freerunner to some kind of sensor.
>> We saw that the debug connector give us the SPI bus.
>> is it a good choice ?
>
> It has been suggested in the past. I don't know if anyone's actually tried it
> yet though.

which ones are the connection used in some other projects ? I wasn't
able to fount any
project involving some hardware extension.

>> is there a point where to take power near there (the debug connector
>> doesn't export it...
>
> R4701 and R4702 next to the debug connector have one end on the IO 3.3V line,
> but may not be a good place to pull power from. R7802 on the other side of
> the speaker has the 3.3V supply for the accelerometer which may be better. It
> probably depends on your power supply requirements though.
>
> I assume you've found the schematics:
> http://downloads.openmoko.org/schematics/GTA02/
>

Yes, we have the schematics, but we really miss a good hardware hacker
between us :)
the 3.3V supply seems fine. le'ts give it a try. we have to give power
to an OPAMP.

I didn't check if the soundcard is easily reachable, but we may
substitute the ADC on the
external sensor with it (opamps are always needed to get a bigger signal).

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-- 
Alessandro Sappia
a.sappia at gmail.com