Ben and Ethernet
Werner Almesberger
werner at openmoko.org
Tue Aug 31 08:45:07 EDT 2010
Rikard Lindstr?m wrote:
> i was thinking of etching a 0.8mm thick PCB (single
> sided) that fits in the microSD-slot and continues outside,
That's actually a nice idea for making extensions. More friendly than
having to wire everything to TPs.
One limitation seems to be that you couldn't do hardware-accelerated
SPI. (The MMC/SD controller supports MMC bus widths of 1 and 4 bits,
but I don't see a "downgrade to SPI" option with separate data lines
for input and output.)
But you'd still have bit-banging GPIO.
Suggestion: design a very simple boards with a bunch of LEDs or such
to demo the concept. Then anyone else can build their stuff upon a
proven design, with proven design files.
- Werner
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