I am looking for an example code for interfacing a 96AB2 keypad with a 9S12DP256B MCU.
Currently I am stuck with a nonworking code from an old book. I've connected pins of the keypad to PORT A and the code goes as follows
DDRA = 0xF8; // set PORTA[0:2] as input and PORTA[3:7] as output
PORTA = 0xBF; // assert row 0
keypress = PORTA;
if (keypress != 0xBF) // some key has been pressed
key = scan_key(keypress);
I've a similar block for every row but I'm not even sure if this is the correct way of doing that and unfortunately I am not getting any results with it. I would really appreciate if someone could give me some hints or pointers to a working code.
Thanks in advance.