Am Do 29. Mai 2008 schrieb [EMAIL PROTECTED]: > Hi Joerg, > as it seems that my mail did not reach the community list (I am not a subscriber, just monitoring the archives) may I ask you directly the question regarding "multi tutch" :-) . See below: > > > Hi all, > if the geometric average point is returned if multiple points are touched wouldn't it be possible to have a fake multi touch, e.g., by doing the following: > > Press point A > -> Vector A is returned > Additionally press desired point B > -> X = (A+B)/2 is returned > -> calculate B = 2*X-A > > Questions: > Would this be managable? > What time difference would be required between first and second (and third ...) touch, to recognize such a multi-touch action and reliable distinguish it from a single touch at position X? > > And one more comment: If that would work you could also detect multi-touch gestures (even if limited), e.g., use the first point statically (maybe a focus centre) and handle the second point dynamically (maybe for zooming in and out). > > > Boris
there are two resistors in the touchpad, one for X and one for Y. We only see them changing on a touch, thus giving us the coords. A concurrent second touch just changes the R values even more, but we get no info about whether we touched a second point or we moved the finger. So what you suggest is a gesture recognition. Things become nasty because even the "geometric middle" isn't true but depends on pressure of one to pressure of other touchpoint etc. You really get too few info out of the device to do anything reasonable with it beyond singletouch (at least that's the way it is now. I plan to see whether we can exploit dynamic pulse response of this design to get some additional info. Same way you're testing cat5-cable for breaks. Don't hold your breath though, chances are bad. And it's not on top of my todo-list) cheers jOERG
signature.asc
Description: This is a digitally signed message part.
_______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community