matrix.c (3256B)
1 /* 2 Copyright 2014 Ralf Schmitt <ralf@bunkertor.net> 3 Modified by Ryan Skidmore <rskeys@ryanskidmore.co.uk> (@ryanskidmore) 4 to support the rskeys100. 5 6 This program is free software: you can redistribute it and/or modify 7 it under the terms of the GNU General Public License as published by 8 the Free Software Foundation, either version 2 of the License, or 9 (at your option) any later version. 10 11 This program is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 GNU General Public License for more details. 15 16 You should have received a copy of the GNU General Public License 17 along with this program. If not, see <http://www.gnu.org/licenses/>. 18 */ 19 20 #include "matrix.h" 21 #include <util/delay.h> 22 23 static const uint32_t col_values[24] = SHR_COLS; 24 25 static uint8_t read_rows(void); 26 static void select_col(uint8_t col); 27 28 static void shift_pulse(void); 29 static void shift_out_single(uint8_t value); 30 static void shift_out(uint32_t value); 31 32 void matrix_init_custom(void) { 33 gpio_set_pin_input(ROW_A); 34 gpio_set_pin_input(ROW_B); 35 gpio_set_pin_input(ROW_C); 36 gpio_set_pin_input(ROW_D); 37 gpio_set_pin_input(ROW_E); 38 gpio_set_pin_input(ROW_F); 39 40 gpio_set_pin_output(SHR_DATA); 41 gpio_set_pin_output(SHR_LATCH); 42 gpio_set_pin_output(SHR_CLOCK); 43 } 44 45 bool matrix_scan_custom(matrix_row_t current_matrix[]) { 46 bool changed = false; 47 48 for (uint8_t col = 0; col < MATRIX_COLS; col++) { 49 select_col(col); 50 _delay_us(1); 51 uint8_t rows = read_rows(); 52 for (uint8_t row = 0; row < MATRIX_ROWS; row++) { 53 bool prev_bit = ((uint32_t)(current_matrix[row]) & (matrix_row_t)(1UL << col)) ? 1 : 0; 54 bool curr_bit = ((uint32_t)rows & (uint32_t)(1UL << row)) ? 1 : 0; 55 if (prev_bit != curr_bit) { 56 current_matrix[row] = (uint32_t)(current_matrix[row]) ^ (uint32_t)(1UL << col); 57 changed = true; 58 } 59 } 60 } 61 62 return changed; 63 } 64 65 static uint8_t read_rows(void) { 66 return (gpio_read_pin(ROW_F) << 5) 67 | (gpio_read_pin(ROW_E) << 4) 68 | (gpio_read_pin(ROW_D) << 3) 69 | (gpio_read_pin(ROW_C) << 2) 70 | (gpio_read_pin(ROW_B) << 1) 71 | (gpio_read_pin(ROW_A) ); 72 } 73 74 static void select_col(uint8_t col) { 75 shift_out(col_values[col]); 76 } 77 78 static void shift_out(uint32_t value) { 79 gpio_write_pin_low(SHR_LATCH); 80 uint8_t first_byte = (value >> 16) & 0xFF; 81 uint8_t second_byte = (value >> 8) & 0xFF; 82 uint8_t third_byte = (uint8_t)(value & 0xFF); 83 84 shift_out_single(first_byte); 85 shift_out_single(second_byte); 86 shift_out_single(third_byte); 87 gpio_write_pin_high(SHR_LATCH); 88 /* We delay here to prevent multiple consecutive keys being triggered with a single switch press */ 89 _delay_us(10); 90 } 91 92 static void shift_out_single(uint8_t value) { 93 for (uint8_t i = 0; i < 8; i++) { 94 if (value & 0b10000000) { 95 gpio_write_pin_high(SHR_DATA); 96 } else { 97 gpio_write_pin_low(SHR_DATA); 98 } 99 100 shift_pulse(); 101 value = value << 1; 102 } 103 } 104 105 static inline void shift_pulse(void) { 106 gpio_write_pin_high(SHR_CLOCK); 107 gpio_write_pin_low(SHR_CLOCK); 108 }