2 Copyright 2019 Alex Ong<the.onga@gmail.com>
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 This program is distributed in the hope that it will be useful,
8 but WITHOUT ANY WARRANTY; without even the implied warranty of
9 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 GNU General Public License for more details.
11 You should have received a copy of the GNU General Public License
12 along with this program. If not, see <http://www.gnu.org/licenses/>.
16 Basic per-row algorithm. Uses an 8-bit counter per row.
17 After pressing a key, it immediately changes state, and sets a counter.
18 No further inputs are accepted until DEBOUNCE milliseconds have occurred.
30 #define debounce_counter_t uint8_t
32 static debounce_counter_t *debounce_counters;
33 static bool counters_need_update;
35 #define DEBOUNCE_ELAPSED 251
36 #define MAX_DEBOUNCE (DEBOUNCE_ELAPSED - 1)
38 void update_debounce_counters(uint8_t num_rows, uint8_t current_time);
39 void transfer_matrix_values(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, uint8_t current_time);
41 // we use num_rows rather than MATRIX_ROWS to support split keyboards
42 void debounce_init(uint8_t num_rows) {
43 debounce_counters = (debounce_counter_t *)malloc(num_rows * sizeof(debounce_counter_t));
44 for (uint8_t r = 0; r < num_rows; r++) {
45 debounce_counters[r] = DEBOUNCE_ELAPSED;
49 void debounce(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, bool changed) {
50 uint8_t current_time = timer_read() % MAX_DEBOUNCE;
51 if (counters_need_update) {
52 update_debounce_counters(num_rows, current_time);
56 transfer_matrix_values(raw, cooked, num_rows, current_time);
60 // If the current time is > debounce counter, set the counter to enable input.
61 void update_debounce_counters(uint8_t num_rows, uint8_t current_time) {
62 counters_need_update = false;
63 debounce_counter_t *debounce_pointer = debounce_counters;
64 for (uint8_t row = 0; row < num_rows; row++) {
65 if (*debounce_pointer != DEBOUNCE_ELAPSED) {
66 if (TIMER_DIFF(current_time, *debounce_pointer, MAX_DEBOUNCE) >= DEBOUNCE) {
67 *debounce_pointer = DEBOUNCE_ELAPSED;
69 counters_need_update = true;
76 // upload from raw_matrix to final matrix;
77 void transfer_matrix_values(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, uint8_t current_time) {
78 debounce_counter_t *debounce_pointer = debounce_counters;
79 for (uint8_t row = 0; row < num_rows; row++) {
80 matrix_row_t existing_row = cooked[row];
81 matrix_row_t raw_row = raw[row];
83 // determine new value basd on debounce pointer + raw value
84 if (*debounce_pointer == DEBOUNCE_ELAPSED && (existing_row != raw_row)) {
85 *debounce_pointer = current_time;
86 cooked[row] = raw_row;
87 counters_need_update = true;
94 bool debounce_active(void) { return true; }