Dear Friends,

i've been faced with a problem during my graduation project and the problem is:

"when i take the output from p0.0 in the first microcontroller and feed it to 2nd M.controller at the input p0.0 and the external inturrupt pin ,the 2nd MC does not respond to the inturrupt so it does not read the input data"

I think that i need a driving circuit so i tried to :

1-feed the output of the first microconroller to latch and then feed the signal to 2nd MC.

2- use buffer and feed the output to latch and then feed its output -the latch-to the second microcontroller but it does not work.

*note// i put pull up resistor at the output port of the 1st MC.

*both MC are of the same type AT89C51

and now i need your help and i hope that you send me a good driving circuit.


Notes:
The output of the first MC1 is 1010101010101010....

At MC2:

I made the inturrupt on transition and every time the inturrupt occure i read the value at p0.0 of the 2nd MC.

******By the way i'm sure that the software is working since:

when i input the output of the 1st MC to the inturrupt input of the 2nd MC and input manually data to p0.0 at the 2nd MC it woks as expected.
also when i input the output of the 1st MC to the p0.0 input of the 2nd MC and input manually inturrupt to the 2nd MC it woks as expected.
The problem occured when i connect the output of the 1st MC to the p0.0 and inturrupt input of the 2nd MC as i discussed before.
So i think that the problem is in the driving circuit



I'm looking forward a reply as soon as possible.

Yours,

Wesam

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