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                     dprint("bounce!: "); dprintf("%02X", debouncing); dprintln();
 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         xprintf("%02X: %032lb\n", row, bitrev32(matrix_get_row(row)));
 147     }
 148 }
 149
 150 uint8_t matrix_key_count(void)
 151 {
 152     uint8_t count = 0;
 153     for (uint8_t i = 0; i < MATRIX_ROWS; i++) {
 154         count += bitpop32(matrix[i]);
 155     }
 156     return count;
 157 }
 158
 159 /* Row pin configuration
 160  * row: 0   1   2   3   4   5
 161  * pin: B5  B4  B3  B2  B1  B0
 162  */
 163 static void init_rows(void)
 164 {
 165     // Input with pull-up(DDR:0, PORT:1)
 166     DDRB  &= ~0b00111111;
 167     PORTB |= 0b00111111;
 168 }
 169
 170 static uint8_t read_rows(void)
 171 {
 172     return (PINB&(1<<5) ? 0 : (1<<0)) |
 173            (PINB&(1<<4) ? 0 : (1<<1)) |
 174            (PINB&(1<<3) ? 0 : (1<<2)) |
 175            (PINB&(1<<2) ? 0 : (1<<3)) |
 176            (PINB&(1<<1) ? 0 : (1<<4)) |
 177            (PINB&(1<<0) ? 0 : (1<<5));
 178 }
 179
 180 /* Column pin configuration
 181  * col: 0   1   2   3   4   5   6   7   8   9   10  11  12  13  14  15  16
 182  * pin: D5  C7  C6  D4  D0  E6  F0  F1  F4  F5  F6  F7  D7  D6  D1  D2  D3
 183  */
 184 static void unselect_cols(void)
 185 {
 186     // Hi-Z(DDR:0, PORT:0) to unselect
 187     DDRC  |= 0b11000000; // PC: 7 6
 188     PORTC |= 0b11000000;
 189     DDRD  |= 0b11111111; // PD: 7 6 5 4 3 2 1 0
 190     PORTD |= 0b11111111;
 191     DDRE  |= 0b01000000; // PE: 6
 192     PORTE |= 0b01000000;
 193     DDRF  |= 0b11110011; // PF: 7 6 5 4 1 0
 194     PORTF |= 0b11110011;
 195 }
 196
 197 static void select_col(uint8_t col)
 198 {
 199     // Output low(DDR:1, PORT:0) to select
 200     switch (col) {
 201         case 0:
 202             DDRD  |= (1<<5);
 203             PORTD &= ~(1<<5);
 204             break;
 205         case 1:
 206             DDRC  |= (1<<7);
 207             PORTC &= ~(1<<7);
 208             break;
 209         case 2:
 210             DDRC  |= (1<<6);
 211             PORTC &= ~(1<<6);
 212             break;
 213         case 3:
 214             DDRD  |= (1<<4);
 215             PORTD &= ~(1<<4);
 216             break;
 217         case 4:
 218             DDRD  |= (1<<0);
 219             PORTD &= ~(1<<0);
 220             break;
 221         case 5:
 222             DDRE  |= (1<<6);
 223             PORTE &= ~(1<<6);
 224             break;
 225         case 6:
 226             DDRF  |= (1<<0);
 227             PORTF &= ~(1<<0);
 228             break;
 229         case 7:
 230             DDRF  |= (1<<1);
 231             PORTF &= ~(1<<1);
 232             break;
 233         case 8:
 234             DDRF  |= (1<<4);
 235             PORTF &= ~(1<<4);
 236             break;
 237         case 9:
 238             DDRF  |= (1<<5);
 239             PORTF &= ~(1<<5);
 240             break;
 241         case 10:
 242             DDRF  |= (1<<6);
 243             PORTF &= ~(1<<6);
 244             break;
 245         case 11:
 246             DDRF  |= (1<<7);
 247             PORTF &= ~(1<<7);
 248             break;
 249         case 12:
 250             DDRD  |= (1<<7);
 251             PORTD &= ~(1<<7);
 252             break;
 253         case 13:
 254             DDRD  |= (1<<6);
 255             PORTD &= ~(1<<6);
 256             break;
 257         case 14:
 258             DDRD  |= (1<<1);
 259             PORTD &= ~(1<<1);
 260             break;
 261         case 15:
 262             DDRD  |= (1<<2);
 263             PORTD &= ~(1<<2);
 264             break;
 265         case 16:
 266             DDRD  |= (1<<3);
 267             PORTD &= ~(1<<3);
 268             break;
 269     }
 270 }