[Fwd: Re: [sdiy] super-nice LED interface ..]

[Jason Tribbeck]

owner-synth-diy at dropmix.xs4all.nl wrote:
> It seems the light is reflected to adjacent cells, and then
> an average intensity is taken. I also found a quick online
> resource summarizing the photodiode effect with LEDs:
> 
> http://archive.chipcenter.com/eexpert/akruger/akruger042.html

According to that, it appears as though you can illuminate a red LED
with a blue LED - and I would guess a green LED.

Given that you can get arrays of RG and also RGB LEDs, I would expect
that you could use the red LED as the sensor, and the other two for the
source light. These could also be used for displaying the current
'position'.

If I was scanning, I would do it in diagonal rows, so the LEDs are lit
by their immediate neighbours. I feel this would give better accuracy.
-- 
Jason Tribbeck             Director of Support                 Argogroup

t: +44 (0) 1252 705743                           f: +44 (0) 1252 705 706
e: jason.tribbeck at argogroup.com             w: http://www.argogroup.com/
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