79 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			79 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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| Copyright 2021 Chad Austin <chad@chadaustin.me>
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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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| /*
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| Symmetric per-row debounce algorithm. Changes only apply when
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| DEBOUNCE milliseconds have elapsed since the last change.
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| */
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| 
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| #include "matrix.h"
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| #include "timer.h"
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| #include "quantum.h"
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| #include <stdlib.h>
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| 
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| #ifndef DEBOUNCE
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| #    define DEBOUNCE 5
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| #endif
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| 
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| static uint16_t last_time;
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| // [row] milliseconds until key's state is considered debounced.
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| static uint8_t* countdowns;
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| // [row]
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| static matrix_row_t* last_raw;
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| 
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| void debounce_init(uint8_t num_rows) {
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|     countdowns = (uint8_t*)calloc(num_rows, sizeof(uint8_t));
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|     last_raw   = (matrix_row_t*)calloc(num_rows, sizeof(matrix_row_t));
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| 
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|     last_time = timer_read();
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| }
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| 
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| void debounce_free(void) {
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|     free(countdowns);
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|     countdowns = NULL;
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|     free(last_raw);
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|     last_raw = NULL;
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| }
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| 
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| bool debounce(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, bool changed) {
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|     uint16_t now           = timer_read();
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|     uint16_t elapsed16     = TIMER_DIFF_16(now, last_time);
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|     last_time              = now;
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|     uint8_t elapsed        = (elapsed16 > 255) ? 255 : elapsed16;
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|     bool    cooked_changed = false;
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| 
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|     uint8_t* countdown = countdowns;
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| 
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|     for (uint8_t row = 0; row < num_rows; ++row, ++countdown) {
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|         matrix_row_t raw_row = raw[row];
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| 
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|         if (raw_row != last_raw[row]) {
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|             *countdown    = DEBOUNCE;
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|             last_raw[row] = raw_row;
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|         } else if (*countdown > elapsed) {
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|             *countdown -= elapsed;
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|         } else if (*countdown) {
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|             cooked_changed |= cooked[row] ^ raw_row;
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|             cooked[row] = raw_row;
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|             *countdown  = 0;
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|         }
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|     }
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| 
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|     return cooked_changed;
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| }
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| 
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| bool debounce_active(void) {
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|     return true;
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| }
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