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authorMichael Graf <michael.trunner@seitenbau.com>2018-11-20 15:55:35 +0100
committerMichael Graf <michael.trunner@seitenbau.com>2018-11-20 15:55:35 +0100
commitad91454574ad1f0fad73923d04d6d1e037e45fed (patch)
tree9a6f73f899920cef172e9ec90b0aeaf4cedc3c40
parent385de70e4d81670ea12526722b78de9521465da9 (diff)
Adaptive debounce logic
The debounce filtering reports a key/switch change directly, without any extra delay. After that the debounce logic will filter all further changes, until the key/switch reports the same state for the given count of scans. So a perfect switch will get a short debounce period and a bad key will get a much longer debounce period. The result is an adaptive debouncing period for each switch. This value defines how often the same key/switch state has to be detected in successive reads until the next key state can be reported. In other words this value defines the minimum debouncing period for a switch.
-rw-r--r--keyboards/ergodox_ez/config.h17
-rw-r--r--keyboards/ergodox_ez/matrix.c49
2 files changed, 38 insertions, 28 deletions
diff --git a/keyboards/ergodox_ez/config.h b/keyboards/ergodox_ez/config.h
index 7a350183b1..ee768853a9 100644
--- a/keyboards/ergodox_ez/config.h
+++ b/keyboards/ergodox_ez/config.h
@@ -85,17 +85,20 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
#define RGBW 1
-/* "debounce" is measured in keyboard scans. Some users reported
- * needing values as high as 15, which was at the time around 50ms.
+/*
+ * The debounce filtering reports a key/switch change directly,
+ * without any extra delay. After that the debounce logic will filter
+ * all further changes, until the key/switch reports the same state for
+ * the given count of scans.
+ * So a perfect switch will get a short debounce period and
+ * a bad key will get a much longer debounce period.
+ * The result is an adaptive debouncing period for each switch.
+ *
* If you don't define it here, the matrix code will default to
* 5, which is now closer to 10ms, but still plenty according to
* manufacturer specs.
- *
- * Default is quite high, because of reports with some production
- * runs seeming to need it. This may change when configuration for
- * this is more directly exposed.
*/
-#define DEBOUNCE 15
+#define DEBOUNCE 10
#define USB_MAX_POWER_CONSUMPTION 500
diff --git a/keyboards/ergodox_ez/matrix.c b/keyboards/ergodox_ez/matrix.c
index 2e95c83b65..6d5bfca31a 100644
--- a/keyboards/ergodox_ez/matrix.c
+++ b/keyboards/ergodox_ez/matrix.c
@@ -57,6 +57,11 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
/* matrix state(1:on, 0:off) */
static matrix_row_t matrix[MATRIX_ROWS];
+/*
+ * matrix state(1:on, 0:off)
+ * contains the raw values without debounce filtering of the last read cycle.
+ */
+static matrix_row_t raw_matrix[MATRIX_ROWS];
// Debouncing: store for each key the number of scans until it's eligible to
// change. When scanning the matrix, ignore any changes in keys that have
@@ -118,6 +123,7 @@ void matrix_init(void)
// initialize matrix state: all keys off
for (uint8_t i=0; i < MATRIX_ROWS; i++) {
matrix[i] = 0;
+ raw_matrix[i] = 0;
for (uint8_t j=0; j < MATRIX_COLS; ++j) {
debounce_matrix[i * MATRIX_COLS + j] = 0;
}
@@ -151,26 +157,30 @@ void matrix_power_up(void) {
// Returns a matrix_row_t whose bits are set if the corresponding key should be
// eligible to change in this scan.
-matrix_row_t debounce_mask(uint8_t row) {
+matrix_row_t debounce_mask(matrix_row_t rawcols, uint8_t row) {
matrix_row_t result = 0;
- for (uint8_t j=0; j < MATRIX_COLS; ++j) {
- if (debounce_matrix[row * MATRIX_COLS + j]) {
- --debounce_matrix[row * MATRIX_COLS + j];
+ matrix_row_t change = rawcols ^ raw_matrix[row];
+ raw_matrix[row] = rawcols;
+ for (uint8_t i = 0; i < MATRIX_COLS; ++i) {
+ if (debounce_matrix[row * MATRIX_COLS + i]) {
+ --debounce_matrix[row * MATRIX_COLS + i];
} else {
- result |= (1 << j);
+ result |= (1 << i);
}
- }
- return result;
-}
-
-// Report changed keys in the given row. Resets the debounce countdowns
-// corresponding to each set bit in 'change' to DEBOUNCE.
-void debounce_report(matrix_row_t change, uint8_t row) {
- for (uint8_t i = 0; i < MATRIX_COLS; ++i) {
if (change & (1 << i)) {
debounce_matrix[row * MATRIX_COLS + i] = DEBOUNCE;
}
}
+ return result;
+}
+
+matrix_row_t debounce_read_cols(uint8_t row) {
+ // Read the row without debouncing filtering and store it for later usage.
+ matrix_row_t cols = read_cols(row);
+ // Get the Debounce mask.
+ matrix_row_t mask = debounce_mask(cols, row);
+ // debounce the row and return the result.
+ return (cols & mask) | (matrix[row] & ~mask);;
}
uint8_t matrix_scan(void)
@@ -214,15 +224,12 @@ uint8_t matrix_scan(void)
select_row(i + MATRIX_ROWS_PER_SIDE);
// we don't need a 30us delay anymore, because selecting a
// left-hand row requires more than 30us for i2c.
- matrix_row_t mask = debounce_mask(i);
- matrix_row_t cols = (read_cols(i) & mask) | (matrix[i] & ~mask);
- debounce_report(cols ^ matrix[i], i);
- matrix[i] = cols;
+
+ // grab cols from left hand
+ matrix[i] = debounce_read_cols(i);
// grab cols from right hand
- mask = debounce_mask(i + MATRIX_ROWS_PER_SIDE);
- cols = (read_cols(i + MATRIX_ROWS_PER_SIDE) & mask) | (matrix[i + MATRIX_ROWS_PER_SIDE] & ~mask);
- debounce_report(cols ^ matrix[i + MATRIX_ROWS_PER_SIDE], i + MATRIX_ROWS_PER_SIDE);
- matrix[i + MATRIX_ROWS_PER_SIDE] = cols;
+ matrix[i + MATRIX_ROWS_PER_SIDE] = debounce_read_cols(i + MATRIX_ROWS_PER_SIDE);
+
unselect_rows();
}