[sdiy] super-nice LED interface ..

[Jay Vaughan]

>No, as you can see from the diagram on the page, the leds alternate in such
>a way that
>ones adjacent to the point being examined are on, and the light diffuses
>through the finger
>(or possibly reflects from it) to the middle one, which is at the same time
>in receive mode.

so to make this a 'solid block of light', one would have to crank the 
PWM rate of the LED's to twice that which would be used to normally 
do a 'fully lit LED', so that you can have a scan period in the 
detector state .. or .. ?


>I'm not personally impressed by this, I think  capacitive sensors are more
>practical.
>You are going to need a certain amount of processing to try to work out what
>is going on.

true that there appears to be a great deal of processing involved in 
producing such an effect, but if those LED's can be giving feedback 
as well as functioning as an input method, it means far less 
complexity in overall interface design.  if i had a huge pad of these 
light sensors to play with, i'd definitely have a difficult time 
going back to the haptic horror of stiff pots ..

-- 

;

Jay Vaughan