Hi,

I did a simple RC type A to D conversion on the 622JW - not using the
comparator. I got a significant change in reading when the window was / was
not covered.

It does make a difference.

I have never seen it affect program execution though - by that I mean
executing garbage.

Rgds...

...Andy
At 18:59 20/01/99 +0100, you wrote:
>Hi All,
>
>I just read the message from William M. Smithers containing the
>following note :
>
>    (NOTE on A/D code and JW parts: cover the window
>      with something opaque, as light throws off the calibration).
>
>I have always wondered if not covering the window on a JW part with
>some kind of a sticker, could affect any function of the PIC like for
>example the onchip A/D circuit. during software development I always
>leave the window of the PIC clear when testing the application (I hate
>to remove the ever sticking adhesive from window everytime) .
>Sometimes the uncovered PIC stays in the application for weeks under
>daylight (or officelight) environments. I have never experienced
>malfunctioning or strange behaviour.
>
>Any ideas or experiences?
>
>Bye,
>
>Daniel...
>