keyboard/onekey/matrix.c

   1 /*
   2 Copyright 2012 Jun Wako <wakojun@gmail.com>
   3
   4 This program is free software: you can redistribute it and/or modify
   5 it under the terms of the GNU General Public License as published by
   6 the Free Software Foundation, either version 2 of the License, or
   7 (at your option) any later version.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18 /*
  19  * scan matrix
  20  */
  21 #include <stdint.h>
  22 #include <stdbool.h>
  23 #include <avr/io.h>
  24 #include <util/delay.h>
  25 #include "print.h"
  26 #include "debug.h"
  27 #include "util.h"
  28 #include "matrix.h"
  29
  30
  31 #ifndef DEBOUNCE
  32 #   define DEBOUNCE     5
  33 #endif
  34 static uint8_t debouncing = DEBOUNCE;
  35
  36 /* matrix state(1:on, 0:off) */
  37 static matrix_row_t matrix[MATRIX_ROWS];
  38 static matrix_row_t matrix_debouncing[MATRIX_ROWS];
  39
  40 static matrix_row_t read_cols(void);
  41 static void init_cols(void);
  42 static void unselect_rows(void);
  43 static void select_row(uint8_t row);
  44
  45
  46 void matrix_init(void)
  47 {
  48     debug_enable = true;
  49     debug_matrix = true;
  50     debug_mouse = true;
  51     // initialize row and col
  52     unselect_rows();
  53     init_cols();
  54
  55     // initialize matrix state: all keys off
  56     for (uint8_t i=0; i < MATRIX_ROWS; i++) {
  57         matrix[i] = 0;
  58         matrix_debouncing[i] = 0;
  59     }
  60 }
  61
  62 uint8_t matrix_scan(void)
  63 {
  64     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
  65         select_row(i);
  66         _delay_us(30);  // without this wait read unstable value.
  67         matrix_row_t cols = read_cols();
  68         if (matrix_debouncing[i] != cols) {
  69             matrix_debouncing[i] = cols;
  70             if (debouncing) {
  71                 debug("bounce!: "); debug_hex(debouncing); debug("\n");
  72             }
  73             debouncing = DEBOUNCE;
  74         }
  75         unselect_rows();
  76     }
  77
  78     if (debouncing) {
  79         if (--debouncing) {
  80             _delay_ms(1);
  81         } else {
  82             for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
  83                 matrix[i] = matrix_debouncing[i];
  84             }
  85         }
  86     }
  87
  88     return 1;
  89 }
  90
  91 inline
  92 matrix_row_t matrix_get_row(uint8_t row)
  93 {
  94     return matrix[row];
  95 }
  96
  97 /* Column pin configuration
  98  * col: 0
  99  * pin: B0
 100  */
 101 static void  init_cols(void)
 102 {
 103     // Input with pull-up(DDR:0, PORT:1)
 104     DDRB  &= ~(1<<0);
 105     PORTB |=  (1<<0);
 106 }
 107
 108 static matrix_row_t read_cols(void)
 109 {
 110     return (PINB&(1<<0) ? 0 : (1<<0));
 111 }
 112
 113 /* Row pin configuration
 114  * row: 0
 115  * pin: B1
 116  */
 117 static void unselect_rows(void)
 118 {
 119     // Hi-Z(DDR:0, PORT:0) to unselect
 120     DDRB  &= ~0b00000010;
 121     PORTB &= ~0b00000010;
 122 }
 123
 124 static void select_row(uint8_t row)
 125 {
 126     // Output low(DDR:1, PORT:0) to select
 127     switch (row) {
 128         case 0:
 129             DDRB  |= (1<<1);
 130             PORTB &= ~(1<<1);
 131             break;
 132     }
 133 }