Re: [ts-7000] Keypad.c ...Key board routine

[Jim Jackson <>]

On Mon, 10 Mar 2008, LaksCEO wrote:

> Hi
> Can any one tell me how this portion of the code works in the keypad.c 
> program ?
> because when you scan the martix (4x4) each one of the row is made 0 and the 
> column details are read
> in such case the data to be sent out will be 1,2,4 and 8
>
> where as here is it no 0,1,2 and 3 ??

no it wont.

  1 << 0 = 1
  1 << 1 = 2
  etc

>
> unsigned int get_keys(void) {
>
> unsigned int pos, on = 0;
>
> for(pos = 0; pos < 4; pos++) {
>
> *dat = ~(1 << pos);
>
> on |= (~(*dat >> 4) & 0xf) << (4 * pos);
>
> }
>
> return on;
>
>
>
>
>


 
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