macway/matrix.c

   1 /*
   2  * scan matrix
   3  */
   4 #include <stdint.h>
   5 #include <stdbool.h>
   6 #include <avr/io.h>
   7 #include <util/delay.h>
   8 #include "print.h"
   9 #include "util.h"
  10 #include "matrix_skel.h"
  11
  12
  13 // matrix state buffer (key on: 1/key off: 0)
  14 static uint8_t *matrix;
  15 static uint8_t *matrix_prev;
  16 static uint8_t _matrix0[MATRIX_ROWS];
  17 static uint8_t _matrix1[MATRIX_ROWS];
  18
  19 static bool matrix_has_ghost_in_row(uint8_t row);
  20 static uint8_t read_col(void);
  21 static void unselect_rows(void);
  22 static void select_row(uint8_t row);
  23
  24
  25 inline
  26 int matrix_rows(void)
  27 {
  28     return MATRIX_ROWS;
  29 }
  30
  31 inline
  32 int matrix_cols(void)
  33 {
  34     return MATRIX_COLS;
  35 }
  36
  37 // this must be called once before matrix_scan.
  38 void matrix_init(void)
  39 {
  40     // initialize row and col
  41     unselect_rows();
  42     // Input with pull-up(DDR:0, PORT:1)
  43     DDRB = 0x00;
  44     PORTB = 0xFF;
  45
  46     // initialize matrix state: all keys off
  47     for (int i=0; i < MATRIX_ROWS; i++) _matrix0[i] = 0x00;
  48     for (int i=0; i < MATRIX_ROWS; i++) _matrix1[i] = 0x00;
  49     matrix = _matrix0;
  50     matrix_prev = _matrix1;
  51 }
  52
  53 int matrix_scan(void)
  54 {
  55     uint8_t *tmp;
  56
  57     tmp = matrix_prev;
  58     matrix_prev = matrix;
  59     matrix = tmp;
  60
  61     for (int i = 0; i < MATRIX_ROWS; i++) {
  62         unselect_rows();
  63         select_row(i);
  64         _delay_us(30);  // without this wait read unstable value.
  65         matrix[i] = ~read_col();
  66     }
  67     unselect_rows();
  68     return 1;
  69 }
  70
  71 bool matrix_is_modified(void)
  72 {
  73     for (int i = 0; i < MATRIX_ROWS; i++) {
  74         if (matrix[i] != matrix_prev[i])
  75             return true;
  76     }
  77     return false;
  78 }
  79
  80 bool matrix_has_ghost(void)
  81 {
  82     for (int i = 0; i < MATRIX_ROWS; i++) {
  83         if (matrix_has_ghost_in_row(i))
  84             return true;
  85     }
  86     return false;
  87 }
  88
  89 inline
  90 bool matrix_is_on(int row, int col)
  91 {
  92     return (matrix[row] & (1<<col));
  93 }
  94
  95 inline
  96 uint16_t matrix_get_row(int row)
  97 {
  98     return matrix[row];
  99 }
 100
 101 void matrix_print(void)
 102 {
 103     print("\nr/c 01234567\n");
 104     for (int row = 0; row < matrix_rows(); row++) {
 105         phex(row); print(": ");
 106         pbin_reverse(matrix_get_row(row));
 107         if (matrix_has_ghost_in_row(row)) {
 108             print(" <ghost");
 109         }
 110         print("\n");
 111     }
 112 }
 113
 114 int matrix_key_count(void)
 115 {
 116     int count = 0;
 117     for (int i = 0; i < MATRIX_ROWS; i++) {
 118         count += bitpop(matrix[i]);
 119     }
 120     return count;
 121 }
 122
 123 static bool matrix_has_ghost_in_row(uint8_t row)
 124 {
 125     // no ghost exists in case less than 2 keys on
 126     if (((matrix[row] - 1) & matrix[row]) == 0)
 127         return false;
 128
 129     // ghost exists in case same state as other row
 130     for (int i=0; i < MATRIX_ROWS; i++) {
 131         if (i != row && (matrix[i] & matrix[row]) == matrix[row])
 132             return true;
 133     }
 134     return false;
 135 }
 136
 137 static uint8_t read_col(void)
 138 {
 139     return PINB;
 140 }
 141
 142 static void unselect_rows(void)
 143 {
 144     // Hi-Z(DDR:0, PORT:0) to unselect
 145     DDRC  &= ~0b11000000; // PC: 7,6
 146     PORTC &= ~0b11000000;
 147     DDRD  &= ~0b11000111; // PD: 7,6,2,1,0
 148     PORTD &= ~0b11000111;
 149     DDRF  &= ~0b11000000; // PF: 7,6
 150     PORTF &= ~0b11000000;
 151 }
 152
 153 static void select_row(uint8_t row)
 154 {
 155     // Output low(DDR:1, PORT:0) to select
 156     // row: 0    1    2    3    4    5    6    7    8
 157     // pin: PD0, PC7, PD7, PF6, PD6, PD1, PD2, PC6, PF7
 158     switch (row) {
 159         case 0:
 160             DDRD  |= (1<<0);
 161             PORTD &= ~(1<<0);
 162             break;
 163         case 1:
 164             DDRC  |= (1<<7);
 165             PORTC &= ~(1<<7);
 166             break;
 167         case 2:
 168             DDRD  |= (1<<7);
 169             PORTD &= ~(1<<7);
 170             break;
 171         case 3:
 172             DDRF  |= (1<<6);
 173             PORTF &= ~(1<<6);
 174             break;
 175         case 4:
 176             DDRD  |= (1<<6);
 177             PORTD &= ~(1<<6);
 178             break;
 179         case 5:
 180             DDRD  |= (1<<1);
 181             PORTD &= ~(1<<1);
 182             break;
 183         case 6:
 184             DDRD  |= (1<<2);
 185             PORTD &= ~(1<<2);
 186             break;
 187         case 7:
 188             DDRC  |= (1<<6);
 189             PORTC &= ~(1<<6);
 190             break;
 191         case 8:
 192             DDRF  |= (1<<7);
 193             PORTF &= ~(1<<7);
 194             break;
 195     }
 196 }