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Avoid 8-bit timer overflows in debounce algorithms (#12240)

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* Add fast_timer_t that is 16-bit or 32-bit based on architecture

A 16-bit timer will overflow sooner but be faster to compare on AVR.

* Avoid 8-bit timer overflows in debounce algorithms

Count down remaining elapsed time instead of trying to do 8-bit timer
comparisons.

Add a "none" implementation that is automatically used if DEBOUNCE is
0 otherwise it will break the _pk/_pr count down.

* Avoid unnecessary polling of the entire matrix in sym_eager_pk

The matrix only needs to be updated when a debounce timer expires.

* Avoid unnecessary polling of the entire matrix in sym_eager_pr

The matrix only needs to be updated when a debounce timer expires.

The use of the "needed_update" variable is trying to do what
"matrix_need_update" was added to fix but didn't work because it only
applied when all keys finished debouncing.

* Fix sym_defer_g timing inconsistency compared to other debounce algorithms

DEBOUNCE=5 should process the key after 5ms, not 6ms

* Add debounce tests
This commit is contained in:
Simon Arlott 2021-06-09 08:23:21 +01:00 • committed by GitHub
parent f287597c19
commit b829a1d264
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20 changed files with 1588 additions and 92 deletions
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76
quantum/debounce/sym_eager_pr.c
View file

@ -1,5 +1,6 @@
/*
Copyright 2019 Alex Ong<the.onga@gmail.com>
Copyright 2021 Simon Arlott
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
@ -33,27 +34,25 @@ No further inputs are accepted until DEBOUNCE milliseconds have occurred.
# define DEBOUNCE 5
#endif
#define debounce_counter_t uint8_t
// Maximum debounce: 255ms
#if DEBOUNCE > UINT8_MAX
# undef DEBOUNCE
# define DEBOUNCE UINT8_MAX
#endif
typedef uint8_t debounce_counter_t;
#if DEBOUNCE > 0
static bool matrix_need_update;
static debounce_counter_t *debounce_counters;
static fast_timer_t last_time;
static bool counters_need_update;
#define DEBOUNCE_ELAPSED 251
#define MAX_DEBOUNCE (DEBOUNCE_ELAPSED - 1)
#define DEBOUNCE_ELAPSED 0
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);
static void update_debounce_counters(uint8_t num_rows, uint8_t elapsed_time);
static void transfer_matrix_values(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows);
// we use num_rows rather than MATRIX_ROWS to support split keyboards
void debounce_init(uint8_t num_rows) {
@ -63,27 +62,50 @@ void debounce_init(uint8_t num_rows) {
}
}
void debounce_free(void) {
free(debounce_counters);
debounce_counters = NULL;
}
void debounce(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, bool changed) {
uint8_t current_time = wrapping_timer_read();
bool needed_update = counters_need_update;
bool updated_last = false;
if (counters_need_update) {
update_debounce_counters(num_rows, current_time);
fast_timer_t now = timer_read_fast();
fast_timer_t elapsed_time = TIMER_DIFF_FAST(now, last_time);
last_time = now;
updated_last = true;
if (elapsed_time > UINT8_MAX) {
elapsed_time = UINT8_MAX;
}
if (elapsed_time > 0) {
update_debounce_counters(num_rows, elapsed_time);
}
}
if (changed || (needed_update && !counters_need_update) || matrix_need_update) {
transfer_matrix_values(raw, cooked, num_rows, current_time);
if (changed || matrix_need_update) {
if (!updated_last) {
last_time = timer_read_fast();
}
transfer_matrix_values(raw, cooked, num_rows);
}
}
// 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) {
static void update_debounce_counters(uint8_t num_rows, uint8_t elapsed_time) {
counters_need_update = false;
matrix_need_update = false;
debounce_counter_t *debounce_pointer = debounce_counters;
for (uint8_t row = 0; row < num_rows; row++) {
if (*debounce_pointer != DEBOUNCE_ELAPSED) {
if (TIMER_DIFF(current_time, *debounce_pointer, MAX_DEBOUNCE) >= DEBOUNCE) {
if (*debounce_pointer <= elapsed_time) {
*debounce_pointer = DEBOUNCE_ELAPSED;
matrix_need_update = true;
} else {
*debounce_pointer -= elapsed_time;
counters_need_update = true;
}
}
@ -92,8 +114,7 @@ void update_debounce_counters(uint8_t num_rows, uint8_t current_time) {
}
// 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;
static void transfer_matrix_values(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows) {
debounce_counter_t *debounce_pointer = debounce_counters;
for (uint8_t row = 0; row < num_rows; row++) {
matrix_row_t existing_row = cooked[row];
@ -102,11 +123,9 @@ void transfer_matrix_values(matrix_row_t raw[], matrix_row_t cooked[], uint8_t n
// determine new value basd on debounce pointer + raw value
if (existing_row != raw_row) {
if (*debounce_pointer == DEBOUNCE_ELAPSED) {
*debounce_pointer = current_time;
*debounce_pointer = DEBOUNCE;
cooked[row] = raw_row;
counters_need_update = true;
} else {
matrix_need_update = true;
}
}
debounce_pointer++;
@ -114,3 +133,6 @@ void transfer_matrix_values(matrix_row_t raw[], matrix_row_t cooked[], uint8_t n
}
bool debounce_active(void) { return true; }
#else
# include "none.c"
#endif