I've been messing around and having no luck figuring out how I might improve this. Anyone feel like giving me a hand here?
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#ifndef DEBOUNCE
# define DEBOUNCE 5
#endif
static uint8_t debouncing = DEBOUNCE;
/* matrix state(1:on, 0:off) */
static matrix_row_t matrix[MATRIX_ROWS];
static matrix_row_t matrix_debouncing[MATRIX_ROWS];
#ifdef MATRIX_HAS_GHOST
static bool matrix_has_ghost_in_row(uint8_t row);
#endif
static matrix_row_t read_cols(void);
static void unselect_rows(void);
static void select_row(uint8_t row);
static void init_cols(void);
inline
uint8_t matrix_rows(void)
{
return MATRIX_ROWS;
}
inline
uint8_t matrix_cols(void)
{
return MATRIX_COLS;
}
void matrix_init(void)
{
// initialize row and col
unselect_rows();
init_cols();
// Input with pull-up(DDR:0, PORT:1)
DDRF = 0x00;
PORTF = 0xFF;
// initialize matrix state: all keys off
for (uint8_t i=0; i < MATRIX_ROWS; i++) {
matrix[i] = 0;
matrix_debouncing[i] = 0;
}
}
uint8_t matrix_scan(void)
{
for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
select_row(i);
_delay_us(30); // without this wait read unstable value.
matrix_row_t cols = read_cols();
if (matrix_debouncing[i] != cols) {
matrix_debouncing[i] = cols;
if (debouncing) {
debug("bounce!: "); debug_hex(debouncing); debug("\n");
}
debouncing = DEBOUNCE;
}
unselect_rows();
}
if (debouncing) {
if (--debouncing) {
_delay_ms(1);
} else {
for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
matrix[i] = matrix_debouncing[i];
}
}
}
return 1;
}
bool matrix_is_modified(void)
{
if (debouncing) return false;
return true;
}
inline
bool matrix_is_on(uint8_t row, uint8_t col)
{
return (matrix[row] & ((matrix_row_t)1<<col));
}
inline
matrix_row_t matrix_get_row(uint8_t row)
{
return matrix[row];
}
void matrix_print(void)
{
print("\nr/c 01234567\n");
for (uint8_t row = 0; row < matrix_rows(); row++) {
phex(row); print(": ");
pbin_reverse(matrix_get_row(row));
#ifdef MATRIX_HAS_GHOST
if (matrix_has_ghost_in_row(row)) {
print(" <ghost");
}
#endif
print("\n");
}
}
#ifdef MATRIX_HAS_GHOST
inline
static bool matrix_has_ghost_in_row(uint8_t row)
{
// no ghost exists in case less than 2 keys on
if (((matrix[row] - 1) & matrix[row]) == 0)
return false;
// ghost exists in case same state as other row
for (uint8_t i=0; i < MATRIX_ROWS; i++) {
if (i != row && (matrix[i] & matrix[row]))
return true;
}
return false;
}
#endif
/* Col pin configuration
* col: 0 1 2 3 4 5 6 7
* pin: F0 F6 F5 F4 F3 F2 F1 F7
*/
inline
static void init_cols(void)
{
// Input with pull-up(DDR:0, PORT:1)
DDRF &= ~0b11111111;
PORTF |= 0b11111111;
}
static uint8_t read_cols(void)
{
return (PINF&(1<<0) ? 0 : (1<<0)) |
(PINF&(1<<6) ? 0 : (1<<1)) |
(PINF&(1<<5) ? 0 : (1<<2)) |
(PINF&(1<<4) ? 0 : (1<<3)) |
(PINF&(1<<3) ? 0 : (1<<4)) |
(PINF&(1<<2) ? 0 : (1<<5)) |
(PINF&(1<<1) ? 0 : (1<<6)) |
(PINF&(1<<7) ? 0 : (1<<7));
}
inline
static void unselect_rows(void)
{
// Hi-Z(DDR:0, PORT:0) to unselect
DDRC &= ~0b11111111; // PC: 7,6,5,4,3,2,1,0
PORTC &= ~0b11111111;
DDRE &= ~0b00000010; // PE: 1
PORTE &= ~0b00000010;
}
inline
static void select_row(uint8_t row)
{
// Output low(DDR:1, PORT:0) to select
// row: 0 1 2 3 4 5 6 7 8
// pin: PE1, PC7, PC6, PC1, PC4, PC3, PC2, PC5, PC0
switch (row) {
case 0:
DDRE |= (1<<1);
PORTE &= ~(1<<1);
break;
case 1:
DDRC |= (1<<7);
PORTC &= ~(1<<7);
break;
case 2:
DDRC |= (1<<6);
PORTC &= ~(1<<6);
break;
case 3:
DDRC |= (1<<1);
PORTC &= ~(1<<1);
break;
case 4:
DDRC |= (1<<4);
PORTC &= ~(1<<4);
break;
case 5:
DDRC |= (1<<3);
PORTC &= ~(1<<3);
break;
case 6:
DDRC |= (1<<2);
PORTC &= ~(1<<2);
break;
case 7:
DDRC |= (1<<5);
PORTC &= ~(1<<5);
break;
case 8:
DDRC |= (1<<0);
PORTC &= ~(1<<0);
break;
}
}