keyboard/phantom/matrix.c

   1 /* Copyright 2012 Jun Wako <wakojun@gmail.com>
   2  *
   3  * This is heavily based on phantom/board.{c|h}.
   4  * https://github.com/BathroomEpiphanies/AVR-Keyboard
   5  *
   6  * Copyright (c) 2012 Fredrik Atmer, Bathroom Epiphanies Inc
   7  * http://bathroomepiphanies.com
   8  *
   9  * As for liscensing consult with the original files or its author.
  10  */
  11 #include <stdint.h>
  12 #include <stdbool.h>
  13 #include <avr/io.h>
  14 #include <util/delay.h>
  15 #include "print.h"
  16 #include "debug.h"
  17 #include "util.h"
  18 #include "matrix.h"
  19
  20
  21 #ifndef DEBOUNCE
  22 #   define DEBOUNCE     0
  23 #endif
  24 static uint8_t debouncing = DEBOUNCE;
  25
  26 // bit array of key state(1:on, 0:off)
  27 static matrix_row_t matrix[MATRIX_ROWS];
  28 static matrix_row_t matrix_debouncing[MATRIX_ROWS];
  29
  30 static uint8_t read_rows(void);
  31 static void init_rows(void);
  32 static void unselect_cols(void);
  33 static void select_col(uint8_t col);
  34
  35 /* LEDs are on output compare pins OC1B OC1C
  36    This activates fast PWM mode on them.
  37    Prescaler 256 and 8-bit counter results in
  38    16000000/256/256 = 244 Hz blink frequency.
  39    LED_A: Caps Lock
  40    LED_B: Scroll Lock  */
  41 /* Output on PWM pins are turned off when the timer
  42    reaches the value in the output compare register,
  43    and are turned on when it reaches TOP (=256). */
  44 static
  45 void setup_leds(void)
  46 {
  47     TCCR1A |=      // Timer control register 1A
  48         (1<<WGM10) | // Fast PWM 8-bit
  49         (1<<COM1B1)| // Clear OC1B on match, set at TOP
  50         (1<<COM1C1); // Clear OC1C on match, set at TOP
  51     TCCR1B |=      // Timer control register 1B
  52         (1<<WGM12) | // Fast PWM 8-bit
  53         (1<<CS12);   // Prescaler 256
  54     OCR1B = 250;    // Output compare register 1B
  55     OCR1C = 250;    // Output compare register 1C
  56     // LEDs: LED_A -> PORTB6, LED_B -> PORTB7
  57     DDRB  &= 0x3F;
  58     PORTB &= 0x3F;
  59 }
  60
  61 inline
  62 uint8_t matrix_rows(void)
  63 {
  64     return MATRIX_ROWS;
  65 }
  66
  67 inline
  68 uint8_t matrix_cols(void)
  69 {
  70     return MATRIX_COLS;
  71 }
  72
  73 void matrix_init(void)
  74 {
  75     // To use PORTF disable JTAG with writing JTD bit twice within four cycles.
  76     MCUCR |= (1<<JTD);
  77     MCUCR |= (1<<JTD);
  78
  79     // initialize row and col
  80     unselect_cols();
  81     init_rows();
  82     setup_leds();
  83
  84     // initialize matrix state: all keys off
  85     for (uint8_t i = 0; i < MATRIX_ROWS; i++)  {
  86         matrix[i] = 0;
  87         matrix_debouncing[i] = 0;
  88     }
  89 }
  90
  91 uint8_t matrix_scan(void)
  92 {
  93     for (uint8_t col = 0; col < MATRIX_COLS; col++) {  // 0-16
  94         select_col(col);
  95         _delay_us(3);       // without this wait it won't read stable value.
  96         uint8_t rows = read_rows();
  97         for (uint8_t row = 0; row < MATRIX_ROWS; row++) {  // 0-5
  98             bool prev_bit = matrix_debouncing[row] & ((matrix_row_t)1<<col);
  99             bool curr_bit = rows & (1<<row);
 100             if (prev_bit != curr_bit) {
 101                 matrix_debouncing[row] ^= ((matrix_row_t)1<<col);
 102                 if (debouncing) {
 103                     debug("bounce!: "); debug_hex(debouncing); print("\n");
 104                 }
 105                 debouncing = DEBOUNCE;
 106             }
 107         }
 108         unselect_cols();
 109     }
 110
 111     if (debouncing) {
 112         if (--debouncing) {
 113             _delay_ms(1);
 114         } else {
 115             for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
 116                 matrix[i] = matrix_debouncing[i];
 117             }
 118         }
 119     }
 120
 121     return 1;
 122 }
 123
 124 bool matrix_is_modified(void)
 125 {
 126     if (debouncing) return false;
 127     return true;
 128 }
 129
 130 inline
 131 bool matrix_is_on(uint8_t row, uint8_t col)
 132 {
 133     return (matrix[row] & ((matrix_row_t)1<<col));
 134 }
 135
 136 inline
 137 matrix_row_t matrix_get_row(uint8_t row)
 138 {
 139     return matrix[row];
 140 }
 141
 142 void matrix_print(void)
 143 {
 144     print("\nr/c 0123456789ABCDEF\n");
 145     for (uint8_t row = 0; row < MATRIX_ROWS; row++) {
 146         phex(row); print(": ");
 147         print_bin_reverse32(matrix_get_row(row));
 148         print("\n");
 149     }
 150 }
 151
 152 uint8_t matrix_key_count(void)
 153 {
 154     uint8_t count = 0;
 155     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
 156         count += bitpop32(matrix[i]);
 157     }
 158     return count;
 159 }
 160
 161 /* Row pin configuration
 162  * row: 0   1   2   3   4   5
 163  * pin: B0  B1  B2  B3  B4  B5
 164  */
 165 static void init_rows(void)
 166 {
 167     // Input with pull-up(DDR:0, PORT:1)
 168     DDRB  &= ~0b00111111;
 169     PORTB |= 0b00111111;
 170 }
 171
 172 static uint8_t read_rows(void)
 173 {
 174     return (PINB&(1<<0) ? 0 : (1<<0)) |
 175            (PINB&(1<<1) ? 0 : (1<<1)) |
 176            (PINB&(1<<2) ? 0 : (1<<2)) |
 177            (PINB&(1<<3) ? 0 : (1<<3)) |
 178            (PINB&(1<<4) ? 0 : (1<<4)) |
 179            (PINB&(1<<5) ? 0 : (1<<5));
 180 }
 181
 182 /* Column pin configuration
 183  * col: 0   1   2   3   4   5   6   7   8   9   10  11  12  13  14  15  16
 184  * pin: D5  C7  C6  D4  D0  E6  F0  F1  F4  F5  F6  F7  D7  D6  D1  D2  D3
 185  */
 186 static void unselect_cols(void)
 187 {
 188     // Hi-Z(DDR:0, PORT:0) to unselect
 189     DDRC  |= 0b11000000; // PC: 7 6
 190     PORTC |= 0b11000000;
 191     DDRD  |= 0b11111111; // PD: 7 6 5 4 3 2 1 0
 192     PORTD |= 0b11111111;
 193     DDRE  |= 0b01000000; // PE: 6
 194     PORTE |= 0b01000000;
 195     DDRF  |= 0b11110011; // PF: 7 6 5 4 1 0
 196     PORTF |= 0b11110011;
 197 }
 198
 199 static void select_col(uint8_t col)
 200 {
 201     // Output low(DDR:1, PORT:0) to select
 202     switch (col) {
 203         case 0:
 204             DDRD  |= (1<<5);
 205             PORTD &= ~(1<<5);
 206             break;
 207         case 1:
 208             DDRC  |= (1<<7);
 209             PORTC &= ~(1<<7);
 210             break;
 211         case 2:
 212             DDRC  |= (1<<6);
 213             PORTC &= ~(1<<6);
 214             break;
 215         case 3:
 216             DDRD  |= (1<<4);
 217             PORTD &= ~(1<<4);
 218             break;
 219         case 4:
 220             DDRD  |= (1<<0);
 221             PORTD &= ~(1<<0);
 222             break;
 223         case 5:
 224             DDRE  |= (1<<6);
 225             PORTE &= ~(1<<6);
 226             break;
 227         case 6:
 228             DDRF  |= (1<<0);
 229             PORTF &= ~(1<<0);
 230             break;
 231         case 7:
 232             DDRF  |= (1<<1);
 233             PORTF &= ~(1<<1);
 234             break;
 235         case 8:
 236             DDRF  |= (1<<4);
 237             PORTF &= ~(1<<4);
 238             break;
 239         case 9:
 240             DDRF  |= (1<<5);
 241             PORTF &= ~(1<<5);
 242             break;
 243         case 10:
 244             DDRF  |= (1<<6);
 245             PORTF &= ~(1<<6);
 246             break;
 247         case 11:
 248             DDRF  |= (1<<7);
 249             PORTF &= ~(1<<7);
 250             break;
 251         case 12:
 252             DDRD  |= (1<<7);
 253             PORTD &= ~(1<<7);
 254             break;
 255         case 13:
 256             DDRD  |= (1<<6);
 257             PORTD &= ~(1<<6);
 258             break;
 259         case 14:
 260             DDRD  |= (1<<1);
 261             PORTD &= ~(1<<1);
 262             break;
 263         case 15:
 264             DDRD  |= (1<<2);
 265             PORTD &= ~(1<<2);
 266             break;
 267         case 16:
 268             DDRD  |= (1<<3);
 269             PORTD &= ~(1<<3);
 270             break;
 271     }
 272 }