PS/2 Keyboard with C

Altera_Forum · ‎05-12-2012

Hello,

i am trying to make a PS/2 Keyboard work with my FPGA and C language.

I tried to capture sequences from the keyboard by using the following code :

    while(1)
    {
        while(1)
        {
            if(*ps2Data!=1)
            {
                printf("%d", *ps2Data);
                printf("%d", *ps2Data);
                printf("%d", *ps2Data);
                printf("%d", *ps2Data);
                printf("\n");
                break;   
            }
        }
        usleep(500000);
    }

However the sequences that i had captured are not always the same for 1 key they can be the same for two different keys.

For instance, when i pressed the 0 from the keypad it gave this (from the console) :

0001

0101

0001

And when i pressed the letter "N" i had :

0001

0101

0001

I know that there is a sequence when the key is pushed and an other one when the key is released, but i don't think that this is my problem.

Actually i only need the 0-9 digits from the keypad which should be easier to implement (i guess).

How could i do to capture the right sequences from the keyboard by using C ?

Thank you for helping me :)

Altera_Forum · ‎05-14-2012

What ps2Data is? Is it a pointer to the rx register of your ps2 serial port?

Why do you read it 4 times?

And, what's the meaning of if(*ps2Data!=1) ?

Usually you need to test a "rx ready" bit on rx status register in order to know if new data word is available.