How does this sound?

In the CNI interrupt routine:
if(!ALL_ROWS) // if key is pressed
{
disable CNI interrupt;  // Or at least disable the key inputs, if using=20
CNI for other interrupts
start timerX to time 20mS;
enable timerX interrupt;
}

In timerX interrupt routine:
enable CNI interrupt;

This assumes you have a spare timer available.  If not, do you have a=20
time keeping interrupt, or something similar?

Kerry


Andre Abelian wrote:
> Hi all,
>
> I am reading a keypad that is connected to other board. I am using PIC24F=
J256GB110
> with CCS PICC compiler. I am using CNI interrupt "port on change" and con=
netced to all 4 rows.
> any time any row goes low it create interrupt but also when it goes high =
creates interrupt too.
> the problem I am having is that I am getting duplicated key "debounce iss=
ue". Normally=20
> I used a counter to deal with debouning or adding a delay. Since CNI inte=
rrupt is not looping
> is like one time shot unless there is a port change using a counter is no=
t working. I also have option=20
> using columns but this will create interrupt every 1.5 ms none stop. usin=
g rows will create interupt
> only when keys are pushed.
>
> any idea? or suggestions will appreciate=20
> here is the code.
>
>
> // Keypad layout:=20
> char const KEYS[4][4] =3D=20
> {{'1','2','3','A'},=20
>  {'4','5','6','B'},=20
>  {'7','8','9','C'},=20
>  {'*','0','#','D'}};=20
>
> // check all rows and return 1 when pushed else return 0
> int1 ALL_ROWS(void)=20
> {=20
> if((input(row0)) & (input(row1)) & (input(row2)) & (input(row3)))  // if =
any of them pushed return 1
>   {=20
>   return (0);
>   } =20
> else
>   {=20
>   return (1);
>   }=20
> }=20
>
>
>
>
> // read keypad but from other board. keypad is connected to other PCB=20
> #int_cni  //level=3D7
> void keypad_interrupt()
> {
> //int32 prg_counter=3D0,data_prg=3D0,read_index_counter[3];       // all =
this is for other routine that is removed for now
>     restart_wdt();
>
>         delay_ms(5);   // for debounce purpose=20
>
>         if((ALL_ROWS())&&(system_keypad_send_once =3D=3D 1)) // any of 4 =
inputs are pressed? row0 & row1 & row2 & row3=20
>             {=20
>        redled_on;    =20
>           // col0 1,4,7,*
>           if((!input(row0))&&(!input(col0)))=20
>                {=20
>             row=3D0; col=3D0;
>             kbd_down =3D true;=20
>             key_pressed =3DKEYS[row][col];
>             system_keypad_send_once =3D 0;
>                } =20
>            if((!input(row1))&&(!input(col0)))
>               {=20
>             row=3D1; col=3D0;
>             kbd_down =3D true;=20
>             key_pressed =3DKEYS[row][col];
>             system_keypad_send_once =3D 0;
>               }=20
>            if((!input(row2))&&(!input(col0)))
>               {=20
>             row=3D2; col=3D0;
>             kbd_down =3D true;=20
>             key_pressed =3DKEYS[row][col];
>             system_keypad_send_once =3D 0;
>               }=20
>            if((!input(row3))&&(!input(col0)))
>               {=20
>             row=3D3; col=3D0;
>             kbd_down =3D true;=20
>             key_pressed =3DKEYS[row][col];
>             system_keypad_send_once =3D 0;
>               }  =20
>              =20
>            =20
>            // col1  2,5,8,0   =20
>             if((!input(row0))&&(!input(col1)))
>              {=20
>             row=3D0; col=3D1;
>             kbd_down =3D true;=20
>             key_pressed =3DKEYS[row][col];
>             system_keypad_send_once =3D 0;
>               } =20
>
>            if((!input(row1))&&(!input(col1)))
>               {=20
>             row=3D1; col=3D1;
>             kbd_down =3D true;=20
>             key_pressed =3DKEYS[row][col];
>             system_keypad_send_once =3D 0;
>               }=20
>                      =20
>            if((!input(row2))&&(!input(col1)))
>               {=20
>             row=3D2; col=3D1;
>             kbd_down =3D true;=20
>             key_pressed =3DKEYS[row][col];
>             system_keypad_send_once =3D 0;
>               }=20
>           =20
>            if((!input(row3))&&(!input(col1)))
>               {=20
>             row=3D3; col=3D1;
>             kbd_down =3D true;=20
>             key_pressed =3DKEYS[row][col];
>             system_keypad_send_once =3D 0;
>               }   =20
>   =20
>           // col2  3,6,9,#
>           if((!input(row0))&&(!input(col2)))
>              {=20
>             row=3D0; col=3D2;
>             kbd_down =3D true;=20
>             key_pressed =3DKEYS[row][col];
>             system_keypad_send_once =3D 0;
>               } =20
>
>            if((!input(row1))&&(!input(col2)))
>               {=20
>             row=3D1; col=3D2;
>             kbd_down =3D true;=20
>             key_pressed =3DKEYS[row][col];
>             system_keypad_send_once =3D 0;
>               }=20
>                      =20
>            if((!input(row2))&&(!input(col2)))
>               {=20
>             row=3D2; col=3D2;
>             kbd_down =3D true;=20
>             key_pressed =3DKEYS[row][col];
>             system_keypad_send_once =3D 0;
>               }=20
>           =20
>            if((!input(row3))&&(!input(col2)))
>               {=20
>             row=3D3; col=3D2;
>             kbd_down =3D true;=20
>             key_pressed =3DKEYS[row][col];
>             system_keypad_send_once =3D 0;
>               }   =20
>          fprintf(ZBEE,"%c", key_pressed);      // print for test normally=
 not used
>
>          }
>          else
>          {
>        redled_off;   =20
>          kbd_down =3D false;                     //=20
>          system_keypad_send_once =3D 1;=20
>          }
>
>
> thanks
>
> Andre=20
>  =20

--=20
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