Keypad Programming

hi, Ajay plz make me understand this section of code.

 unsigned char get_key(){
        unsigned char i,k,key=0;
        k=1;
        for(i=0;i<4;i++){
                keyport &=~(0x80>
>
i);
                        if(!col1){
                                key = k+0;
                                while(!col1);
                                return key;
                        }
                        if(!col2){
                                key = k+1;
                                while(!col2);
                                return key;
                        }
                        if(!col3){
                                key = k+2;
                                while(!col3);
                                return key;
                        }
                        if(!col4){
                                key = k+3;
                                while(!col4);
                                return key;
                        }
                k+=4;
                keyport |= 0x80>
>
i;
        }
        return FALSE; 
}
 

I will put comments on the tutorial do not worry..
Everything is same as i did in AVR program. Please wait till tonight so that i can update the tutorial with comments. If you are in hurry then look at the AVR program, everything is same as this.

hi, Ajay. I visited but not updated yet. plz update it i m waiting.

oww.. i am so sorry.. was busy i will update in a min!

I have updated the tutorial you may check now

Well Ajay, how will i call these keypad routines in assembly and C functions from main program. Plz give me idea in Assebly and C as well.

for assembly.. just type

acall get_key     ;to get the value of key
;it will be stored in keyval variable...

similarly in case of C you can use it as..

key = get_key();
//key number will be returned and assigned to variable key

sorry i couldnt understand how to program with assembler
can you give more information?
thanks a lot

check tutorial page.. i have given code for assembly too.. ask me if you feel any problem