Henry Low wrote:
>
> HI James and everyone, thanks for the prompt reply. I am using both sonar
> and IR for my collision detection. Is it advisable to have sonar sensor as
> its only form of detection??
> Anyway, do u know what the photodiode reacts to?? Normal light or IR?? It is
> an important point for me.


Hi Henry, good to see you got the photodiode
trans/receive pair working ok. The photodiode
type you have responds MAINLY to IR, but remember
that includes sunlight and some heat sources.

To get reliable IR you need to modulate it,
and sense for that modulated frequency with
the photodiode. There are many sources of info
on the web that already have circuits and pictures
and may be a quicker source of info for you than
the piclist.

Try doing a Yahoo.com search for "robot infrared"
:o)
-Roman

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