matrix.c (3251B)
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 19 // PCA9555 slave addresses 20 #define IC1 0x20 21 #define IC2 0x21 22 23 //_____Utility funcs___________________________________________________________ 24 25 static void init_pins(void) { 26 // init all cols high - IC2 all input 27 pca9555_set_config(IC2, PCA9555_PORT0, ALL_INPUT); // same as initial state 28 pca9555_set_config(IC2, PCA9555_PORT1, ALL_INPUT); // same as initial state 29 30 // init all rows - IC1 port0 input 31 pca9555_set_config(IC1, PCA9555_PORT0, ALL_INPUT); // same as initial state 32 pca9555_set_output(IC1, PCA9555_PORT0, ALL_LOW); 33 } 34 35 static void select_row(uint8_t row) { 36 // For the XD84 all rows are on the same IC and port 37 // so its safe enough to assume here row == pin 38 uint8_t pin = row; 39 uint8_t mask = 1 << pin; 40 41 // we configure output once in init, as pca9555 remembers state when flipping between input/output 42 // pca9555_set_output(IC1, PCA9555_PORT0, ALL_HIGH & (~mask)); 43 pca9555_set_config(IC1, PCA9555_PORT0, ALL_INPUT & (~mask)); 44 } 45 46 static uint16_t read_cols(void) { 47 // uint16_t state_1 = pca9555_read_pins(IC2, PCA9555_PORT0); 48 // uint16_t state_2 = pca9555_read_pins(IC2, PCA9555_PORT1); 49 uint16_t state = 0; 50 pca9555_read_pins_all(IC2, &state); 51 52 // For the XD84 all cols are on the same IC and mapped sequentially 53 // while this technically gives 16 column reads, 54 // the 16th column can never be set so is safely ignored 55 // return ~((state_2 << 8) | state_1); 56 return ~state; 57 } 58 59 static bool read_cols_on_row(matrix_row_t current_matrix[], uint8_t current_row) { 60 // Store last value of row prior to reading 61 matrix_row_t last_row_value = current_matrix[current_row]; 62 63 // Clear data in matrix row 64 current_matrix[current_row] = 0; 65 66 // Select row and wait for row selection to stabilize 67 select_row(current_row); 68 // Skip the wait_us(30); as i2c is slow enough to debounce the io changes 69 70 current_matrix[current_row] = read_cols(); 71 72 // No need to Unselect row as the next `select_row` will blank everything 73 74 return (last_row_value != current_matrix[current_row]); 75 } 76 77 //_____CUSTOM MATRIX IMPLEMENTATION____________________________________________________ 78 79 void matrix_init_custom(void) { 80 pca9555_init(IC1); 81 pca9555_init(IC2); 82 83 init_pins(); 84 } 85 86 bool matrix_scan_custom(matrix_row_t current_matrix[]) { 87 bool changed = false; 88 for (uint8_t current_row = 0; current_row < MATRIX_ROWS; current_row++) { 89 changed |= read_cols_on_row(current_matrix, current_row); 90 } 91 return changed; 92 }