3×5 keypad interfacing with at89s52

[digitalkim]

can anybody suggest how can i interface 3×5 keypad with aat89s52 controller..
can i convert 20 key controller ic 74c923 to 15 key controller by connecting one of the x1,...x4 keys to permanently ground or vcc.
if yes wat shud i connect to that pin -vcc or gnd.?
thanks in advance...

 

[rushi53]

As per my view, you don't need to connect any IC between microcontroller and keypad.
Connect the matrix keypad directly to microcontroller.
You can find a similar code here:
https://www.projectsof8051.com/downloads/asmcodes/8051-matrix-keypad.html
This code is for 3x4 matrix keypad, modify it for a 3x5 keypad.

 

[digitalkim]

thnks for the reply..
but the keypad i've has no vcc or gnd simple switches are there....
and thats y its not detected by the controller..m using at89s52 controller
n please if possible help me thru c code..
i dont understng asm code much.i find it tough...
thanks once again.....

 

[omid_azmoon]

connect your keypad to 74923,then out put interrupt of this must be connected to micro.when you press any key micro goes to interrupt routin , then you can read output of 74923.

 

[digitalkim]

hi
thanks for the reply
can u please give me the c code for this....
thanks....