/*
* keypad_write_cols: write all 16 column bits in 'val' to shift register.
*/
static void keypad_write_cols( short val )
{
int i;
for( i = 0; i < MAX_COLS; i++ )
{
if( val < 0 )
data_h( );
else
data_l( );
clk_h( );
val <<= 1;
clk_l( );
}
}
void put_9200a(uint8 value)
{
int8 i;
// PORTC &= !DIAL_CS; //put 0,enable CS
for(i = 4; i >= 0 ; i--)
{
clk_h();
put_value((value >> i) & 0x01);
__delay_cycles(20);
clk_l();
__delay_cycles(20);
}
__delay_cycles(20);
__delay_cycles(20);
// PORTC |= DIAL_CS;
}
/*
* keypad_scan: perform a single scan of keyboard. Returns keycode of
* key that was pressed (or -1 if nothing).
*/
int keypad_scan( void )
{
int row, col;
int pressed = -1;
leds_off( ); // turn off LEDs during scan
keypad_write_cols( ~1 ); // single zero at column 0
data_h( ); // shift in ones
for( col = 0; col < MAX_COLS; col++ )
{
keypad_state[col] = get_rows( );
clk_h( );
clk_l( );
}
keypad_write_cols( ~leds );
leds_on( );
// keyboard has been scanned, now look for pressed keys
for( col = 0; col < MAX_COLS; col++ )
{
uint8_t diff = keypad_state[col] ^ keypad_prev[col];
if( diff )
{
for( row = 0; row < MAX_ROWS; row++ )
{
uint8_t mask = 1 << row;
if( diff & mask & keypad_state[col] )
pressed = row * 16 + col;
}
}
keypad_prev[col] = keypad_state[col];
}
return pressed;
}