ps2 keyboard sending the same value twice with 8051

[ucsam]

I am using 8051 and the keyboard is sending the same data twice. Is there something i dont know about how keyboard sends the data?

 

[fouwad]

where is it sending and how? from uart? if yes then it may b echo that is sending it twice

 

[andre_luis]

There are also anohter variables.
For instance : Are you flagging in the code program each read once to avoid multiple readings ?

Some answer is imprecise without more details.

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[IanP]

Be careful not to read the PRESS and then the RELEASE codes.
For example,
PRESS code for "A" is 1C
RELEASE code for "A is FO 1C
In both cases you have 1C, so if you omit somewhere F0 as RELEASE, you will read the same code twice ..

see:
The PS2 protocol

:wink:
IanP

 

[ucsam]

i have a library that looks after the hardware stuffs
i do have a function the asks me whether to take the data on release or on press so thats not my problem.
are there any other cases?

 

[andre_luis]

Maybe Keyboard doesn´t have the hardware dobouce properly designed.
Exchange for other, to check if problem persists.


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