123 lines
3.3 KiB
C
123 lines
3.3 KiB
C
/*
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Copyright 2017 Alex Ong<the.onga@gmail.com>
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/*
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Basic per-key algorithm. Uses an 8-bit counter per key.
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After pressing a key, it immediately changes state, and sets a counter.
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No further inputs are accepted until DEBOUNCE milliseconds have occurred.
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*/
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#include "debounce.h"
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#include "matrix.h"
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#include "timer.h"
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#ifndef DEBOUNCE
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#define DEBOUNCE 5
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#endif
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#if (MATRIX_COLS <= 8)
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# define ROW_SHIFTER ((uint8_t)1)
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#elif (MATRIX_COLS <= 16)
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# define ROW_SHIFTER ((uint16_t)1)
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#elif (MATRIX_COLS <= 32)
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# define ROW_SHIFTER ((uint32_t)1)
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#endif
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#define debounce_counter_t uint8_t
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static matrix_row_t matrix_debounced[MATRIX_ROWS];
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static debounce_counter_t debounce_counters[MATRIX_ROWS*MATRIX_COLS];
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#define DEBOUNCE_ELAPSED 251
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#define MAX_DEBOUNCE (DEBOUNCE_ELAPSED - 1)
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void update_debounce_counters(uint8_t current_time);
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void transfer_matrix_values(uint8_t current_time);
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void matrix_debounce_init(void)
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{
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for (uint8_t r = 0; r < MATRIX_ROWS; r++)
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{
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matrix_debounced[r] = 0;
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}
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int i = 0;
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for (uint8_t r = 0; r < MATRIX_ROWS; r++)
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{
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for (uint8_t c = 0; c < MATRIX_COLS; c++)
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{
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debounce_counters[i++] = DEBOUNCE_ELAPSED;
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}
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}
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}
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void matrix_debounce(void)
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{
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uint8_t current_time = timer_read() % MAX_DEBOUNCE;
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update_debounce_counters(current_time);
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transfer_matrix_values(current_time);
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}
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//If the current time is > debounce counter, set the counter to enable input.
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void update_debounce_counters(uint8_t current_time)
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{
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debounce_counter_t *debounce_pointer = debounce_counters;
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for (uint8_t row = 0; row < MATRIX_ROWS; row++)
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{
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for (uint8_t col = 0; col < MATRIX_COLS; col++)
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{
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if (*debounce_pointer != DEBOUNCE_ELAPSED)
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{
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if (TIMER_DIFF(current_time, *debounce_pointer, MAX_DEBOUNCE) >=
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DEBOUNCING_DELAY) {
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*debounce_pointer = DEBOUNCE_ELAPSED;
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}
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}
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debounce_pointer++;
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}
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}
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}
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// upload from raw_matrix to final matrix;
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void transfer_matrix_values(uint8_t current_time)
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{
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debounce_counter_t *debounce_pointer = debounce_counters;
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for (uint8_t row = 0; row < MATRIX_ROWS; row++)
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{
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matrix_row_t existing_row = matrix_debounced[row];
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matrix_row_t raw_row = matrix_get_row(row);
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for (uint8_t col = 0; col < MATRIX_COLS; col++)
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{
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matrix_row_t col_mask = (ROW_SHIFTER << col);
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bool final_value = raw_row & col_mask;
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bool existing_value = existing_row & col_mask;
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if (*debounce_pointer == DEBOUNCE_ELAPSED &&
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(existing_value != final_value))
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{
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*debounce_pointer = current_time;
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existing_row ^= col_mask; //flip the bit.
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}
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debounce_pointer++;
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}
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matrix_debounced[row] = existing_row;
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}
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}
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//Implementation of no debounce.
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