matrix.c (3147B)
1 /* Copyright 2019 2 * 3 * This program is free software: you can redistribute it and/or modify 4 * it under the terms of the GNU General Public License as published by 5 * the Free Software Foundation, either version 2 of the License, or 6 * (at your option) any later version. 7 * 8 * This program is distributed in the hope that it will be useful, 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 * GNU General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public License 14 * along with this program. If not, see <http://www.gnu.org/licenses/>. 15 */ 16 #include "matrix.h" 17 #include "pca9555.h" 18 #include "wait.h" 19 20 // PCA9555 slave addresses 21 #define IC1 0x20 22 #define IC2 0x21 23 24 //_____Utility funcs___________________________________________________________ 25 26 static void init_pins(void) { 27 // init all cols high - IC2 all input 28 pca9555_set_config(IC2, PCA9555_PORT0, ALL_INPUT);//same as initial state 29 pca9555_set_config(IC2, PCA9555_PORT1, ALL_INPUT);//same as initial state 30 pca9555_set_config(IC1, PCA9555_PORT1, ALL_INPUT);//same as initial state 31 32 // init all rows - IC1 port0 input 33 pca9555_set_config(IC1, PCA9555_PORT0, ALL_INPUT);//same as initial state 34 } 35 36 static void select_row(uint8_t row) { 37 // For the XD96 all rows are on the same IC and port 38 // so its safe enough to assume here row == pin 39 uint8_t pin = row; 40 uint8_t mask = 1 << pin; 41 42 pca9555_set_output(IC1, PCA9555_PORT0, ALL_HIGH & (~mask)); 43 pca9555_set_config(IC1, PCA9555_PORT0, ALL_INPUT & (~mask)); 44 } 45 46 static uint32_t read_cols(void) { 47 uint8_t state_1 = 0; 48 uint8_t state_2 = 0; 49 uint8_t state_3 = 0; 50 pca9555_read_pins(IC2, PCA9555_PORT0, &state_1); 51 pca9555_read_pins(IC2, PCA9555_PORT1, &state_2); 52 pca9555_read_pins(IC1, PCA9555_PORT1, &state_3); 53 54 // For the XD96 the pins are mapped to port expanders as follows: 55 // all 8 pins port 0 IC2, first 6 pins port 1 IC2, first 4 pins port 1 IC1 56 uint32_t state = ((((uint32_t)state_3 & 0b00001111) << 14) | (((uint32_t)state_2 & 0b00111111) << 8) | (uint32_t)state_1); 57 return (~state) & 0b111111111111111111; 58 } 59 60 static bool read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row) { 61 // Store last value of row prior to reading 62 matrix_row_t last_row_value = current_matrix[current_row]; 63 64 // Clear data in matrix row 65 current_matrix[current_row] = 0; 66 67 // Select row and wait for row selection to stabilize 68 select_row(current_row); 69 wait_us(30); 70 71 current_matrix[current_row] = read_cols(); 72 73 // No need to Unselect row as the next `select_row` will blank everything 74 75 return (last_row_value != current_matrix[current_row]); 76 } 77 78 //_____CUSTOM MATRIX IMPLEMENTATION____________________________________________________ 79 80 void matrix_init_custom(void) { 81 pca9555_init(IC1); 82 pca9555_init(IC2); 83 84 init_pins(); 85 } 86 87 bool matrix_scan_custom(matrix_row_t current_matrix[]) { 88 bool changed = false; 89 for (uint8_t current_row = 0; current_row < MATRIX_ROWS; current_row++) { 90 changed |= read_cols_on_row(current_matrix, current_row); 91 } 92 return changed; 93 }