Itch1: Spell weaving

Thomas Seiler thseiler at
Wed Jan 24 17:15:18 CET 2007


I like your idea of spell weaving very much. Unfortunately...

> Latest word seems to be that Neo1973 will be single touch only and  
> this
> is hardware limitation.

...which is sad. I suppose the neo1973 is using a resistive
touch-screen. (
Therefore we can't hack the existing touch-screen to be multi-touchable.

However, I don't give up easily. I have seen that cypress produces a  
of mixed signal MCUs ( They have  
on-chip that is needed to build a capacitive touch controller. they  
are not
so expensive and the assembler / IDE is free (as in beer). And the  
performance is
not so bad: apple used a PSOC chip for the clickwheel(tm) in the ipod  
mini series)

By going the capacitive road, it should be possible to have  
multitouch as long as
the two touchpoints are not to close together. (this is basically how  
touchpads for notebooks are build) By locking at the size we will  
probably need
to split the display into upper and lower half and have two  
independent controllers.

So in order to hack this up, we would need:

Hardware Side:
- Someone who can sputter indium-thin-oxide onto a glass-substrate
   Alternatively we might use an old resistive touch-screen for first  
- Someone who can etch a pattern into this.
   There we need someone with knowledge in chemistry .
   (the pattern we need can be seen on one of the pictures in the  
PSOC wikipedia article)

- Oh, and we would need solder points inside the Neo1973 (SPI /  
uart / gpio) to
   connect an alien MCU like the Cypress PSOC.

Software Side:
- kernel level device driver that emulates the interface of the old  
- A new device to access the multi touch information.
- X pointer abstraction ? Dont know nothing about X.
- Some gesture detection ? Dont know nothing about markov.

So is there anyone on this list interested in building such a  
prototype ?
Anyone with experience in working with Indium-Thin-Oxide or other  
conductors ? Anyone who knows how the x pointer stuff works ? Or how  
to write
a gesture detection algo ?

This would really be fun !

Thomas Seiler

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