/* Copyright 2022 * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include "matrix.h" #include "gpio.h" #include "sn74x154.h" static const pin_t row_pins[MATRIX_ROWS] = MATRIX_ROW_PINS; /* All columns use a 74HC154 4-to-16 demultiplexer. * D3 is the enable pin, must be set high to use it. * * A3 A2 A1 A0 * D7 D6 D5 D4 * 0: 0 0 0 0 * 1: 0 0 0 1 * 2: 0 0 1 0 * 3: 0 0 1 1 * 4: 0 1 0 0 * 5: 0 1 0 1 * 6: 0 1 1 0 * 7: 0 1 1 1 * 8: 1 0 0 0 * 9: 1 0 0 1 * 10: 1 0 1 0 * 11: 1 0 1 1 * 12: 1 1 0 0 * 13: 1 1 0 1 * 14: 1 1 1 0 * 15: 1 1 1 1 */ static void select_col(uint8_t col) { sn74x154_set_addr(col); } static void init_pins(void) { for (uint8_t x = 0; x < MATRIX_ROWS; x++) { setPinInputHigh(row_pins[x]); } } static bool read_rows_on_col(matrix_row_t current_matrix[], uint8_t current_col) { bool matrix_changed = false; // Select col and wait for col seleciton to stabilize select_col(current_col); matrix_io_delay(); // For each row... for (uint8_t row_index = 0; row_index < MATRIX_ROWS; row_index++) { // Store last value of row prior to reading matrix_row_t last_row_value = current_matrix[row_index]; // Check row pin state if (readPin(row_pins[row_index]) == 0) { // Pin LO, set col bit current_matrix[row_index] |= (MATRIX_ROW_SHIFTER << current_col); } else { // Pin HI, clear col bit current_matrix[row_index] &= ~(MATRIX_ROW_SHIFTER << current_col); } // Determine if the matrix changed state if ((last_row_value != current_matrix[row_index]) && !(matrix_changed)) { matrix_changed = true; } } return matrix_changed; } void matrix_init_custom(void) { // initialize demultiplexer sn74x154_init(); sn74x154_set_enabled(true); // initialize key pins init_pins(); } bool matrix_scan_custom(matrix_row_t current_matrix[]) { bool changed = false; // Set col, read rows for (uint8_t current_col = 0; current_col < MATRIX_COLS; current_col++) { changed |= read_rows_on_col(current_matrix, current_col); } return changed; }