181 lines
3.9 KiB
C
181 lines
3.9 KiB
C
/*
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* scan matrix
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*/
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#include <avr/io.h>
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#include <util/delay.h>
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#include "keymap.h"
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#include "matrix.h"
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// matrix is active low. (key on: 0/key off: 1)
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// row: Hi-Z(unselected)/low output(selected)
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// PD:0,1,2,3,6,7/PC:6,7/PF:7
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// col: input w/pullup
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// PB:0-8
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// matrix state buffer
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uint8_t *matrix;
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uint8_t *matrix_prev;
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static uint8_t _matrix0[MATRIX_ROWS];
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static uint8_t _matrix1[MATRIX_ROWS];
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static uint8_t read_col(void);
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static void unselect_rows(void);
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static void select_row(uint8_t row);
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// this must be called once before matrix_scan.
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void matrix_init(void)
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{
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// initialize row and col
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unselect_rows();
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DDRB = 0x00;
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PORTB = 0xFF;
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// initialize matrix state: all keys off
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for (int i=0; i < MATRIX_ROWS; i++) _matrix0[i] = 0xFF;
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for (int i=0; i < MATRIX_ROWS; i++) _matrix1[i] = 0xFF;
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matrix = _matrix0;
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matrix_prev = _matrix1;
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}
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uint8_t matrix_scan(void)
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{
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uint8_t row, state;
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uint8_t *tmp;
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tmp = matrix_prev;
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matrix_prev = matrix;
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matrix = tmp;
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for (row = 0; row < MATRIX_ROWS; row++) {
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select_row(row);
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_delay_us(30); // without this wait read unstable value.
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state = read_col();
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unselect_rows();
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matrix[row] = state;
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}
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return 1;
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}
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bool matrix_is_modified(void) {
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for (int i=0; i <MATRIX_ROWS; i++) {
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if (matrix[i] != matrix_prev[i])
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return true;
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}
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return false;
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}
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bool matrix_has_ghost(void) {
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for (int i=0; i <MATRIX_ROWS; i++) {
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if (matrix_has_ghost_in_row(i))
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return true;
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}
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return false;
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}
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bool matrix_has_ghost_in_row(uint8_t row) {
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uint8_t state = ~matrix[row];
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// no ghost exists in case less than 2 keys on
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if (((state - 1) & state) == 0)
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return false;
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// ghost exists in case same state as other row
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for (int i=0; i < MATRIX_ROWS; i++) {
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if (i == row) continue;
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if ((~matrix[i] & state) == state) return true;
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}
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return false;
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}
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static uint8_t read_col(void)
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{
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return PINB;
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}
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static void unselect_rows(void) {
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DDRD = 0x00;
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PORTD = 0x00;
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DDRC = 0x00;
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PORTC = 0x00;
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DDRF = 0x00;
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PORTF = 0x00;
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}
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static void select_row(uint8_t row)
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{
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switch (row) {
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case 0:
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DDRD = (1<<0);
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PORTD = 0x00;
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DDRC = 0x00;
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PORTC = 0x00;
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DDRF = 0x00;
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PORTF = 0x00;
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break;
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case 1:
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DDRD = (1<<1);
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PORTD = 0x00;
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DDRC = 0x00;
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PORTC = 0x00;
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DDRF = 0x00;
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PORTF = 0x00;
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break;
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case 2:
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DDRD = (1<<2);
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PORTD = 0x00;
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DDRC = 0x00;
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PORTC = 0x00;
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DDRF = 0x00;
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PORTF = 0x00;
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break;
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case 3:
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DDRD = (1<<3);
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PORTD = 0x00;
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DDRC = 0x00;
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PORTC = 0x00;
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DDRF = 0x00;
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PORTF = 0x00;
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break;
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case 4:
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DDRD = (1<<6);
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PORTD = 0x00;
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DDRC = 0x00;
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PORTC = 0x00;
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DDRF = 0x00;
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PORTF = 0x00;
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break;
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case 5:
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DDRD = (1<<7);
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PORTD = 0x00;
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DDRC = 0x00;
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PORTC = 0x00;
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DDRF = 0x00;
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PORTF = 0x00;
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break;
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case 6:
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DDRD = 0x00;
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PORTD = 0x00;
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DDRC = (1<<6);
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PORTC = 0x00;
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DDRF = 0x00;
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PORTF = 0x00;
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break;
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case 7:
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DDRD = 0x00;
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PORTD = 0x00;
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DDRC = (1<<7);
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PORTC = 0x00;
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DDRF = 0x00;
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PORTF = 0x00;
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break;
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case 8:
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DDRD = 0x00;
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PORTD = 0x00;
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DDRC = 0x00;
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PORTC = 0x00;
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DDRF = (1<<7);
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PORTF = 0x00;
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break;
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}
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}
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