/* Copyright 2017 Alex Ong<the.onga@gmail.com> 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/>. */ /* Basic per-key algorithm. Uses an 8-bit counter per key. After pressing a key, it immediately changes state, and sets a counter. No further inputs are accepted until DEBOUNCE milliseconds have occurred. */ #include "matrix.h" #include "timer.h" #include "quantum.h" #include <stdlib.h> #ifndef DEBOUNCE # define DEBOUNCE 5 #endif #define ROW_SHIFTER ((matrix_row_t)1) #define debounce_counter_t uint8_t static debounce_counter_t *debounce_counters; static bool counters_need_update; static bool matrix_need_update; #define DEBOUNCE_ELAPSED 251 #define MAX_DEBOUNCE (DEBOUNCE_ELAPSED - 1) static uint8_t wrapping_timer_read(void) { static uint16_t time = 0; static uint8_t last_result = 0; uint16_t new_time = timer_read(); uint16_t diff = new_time - time; time = new_time; last_result = (last_result + diff) % (MAX_DEBOUNCE + 1); return last_result; } void update_debounce_counters(uint8_t num_rows, uint8_t current_time); void transfer_matrix_values(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, uint8_t current_time); // we use num_rows rather than MATRIX_ROWS to support split keyboards void debounce_init(uint8_t num_rows) { debounce_counters = (debounce_counter_t *)malloc(num_rows * MATRIX_COLS * sizeof(debounce_counter_t)); int i = 0; for (uint8_t r = 0; r < num_rows; r++) { for (uint8_t c = 0; c < MATRIX_COLS; c++) { debounce_counters[i++] = DEBOUNCE_ELAPSED; } } } void debounce(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, bool changed) { uint8_t current_time = wrapping_timer_read(); if (counters_need_update) { update_debounce_counters(num_rows, current_time); } if (changed || matrix_need_update) { transfer_matrix_values(raw, cooked, num_rows, current_time); } } // If the current time is > debounce counter, set the counter to enable input. void update_debounce_counters(uint8_t num_rows, uint8_t current_time) { counters_need_update = false; debounce_counter_t *debounce_pointer = debounce_counters; for (uint8_t row = 0; row < num_rows; row++) { for (uint8_t col = 0; col < MATRIX_COLS; col++) { if (*debounce_pointer != DEBOUNCE_ELAPSED) { if (TIMER_DIFF(current_time, *debounce_pointer, MAX_DEBOUNCE) >= DEBOUNCE) { *debounce_pointer = DEBOUNCE_ELAPSED; } else { counters_need_update = true; } } debounce_pointer++; } } } // upload from raw_matrix to final matrix; void transfer_matrix_values(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, uint8_t current_time) { matrix_need_update = false; debounce_counter_t *debounce_pointer = debounce_counters; for (uint8_t row = 0; row < num_rows; row++) { matrix_row_t delta = raw[row] ^ cooked[row]; matrix_row_t existing_row = cooked[row]; for (uint8_t col = 0; col < MATRIX_COLS; col++) { matrix_row_t col_mask = (ROW_SHIFTER << col); if (delta & col_mask) { if (*debounce_pointer == DEBOUNCE_ELAPSED) { *debounce_pointer = current_time; counters_need_update = true; existing_row ^= col_mask; // flip the bit. } else { matrix_need_update = true; } } debounce_pointer++; } cooked[row] = existing_row; } } bool debounce_active(void) { return true; }