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Gday Bill
Not sure ebay was running when this joystick was made :-)
Its definately a forward biased 82V zener ( hence part of my confusion ).
It seems weird to use it here, as it lowers the final voltage into the chip, ( it measures as a 0.545V forward drop ) and this will alter the timing to the (unknown) trip point. As the chip is actually running a program to read the pin, i think i will still need to leave the zeners in there, but finding the exact units is not simple.
I think i will end up doing a simple trial and error once i get the RC circuit right, but would be interested as to why a diode got used here.
Everything is 5V from the USB power so no idea where 82V could come from :-), and as its a well known brand, i have to assume they did it for a reason.
Andrew
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