diff --git a/docs/feature_wpm.md b/docs/feature_wpm.md
index 87145c97e3..9f98ef8336 100644
--- a/docs/feature_wpm.md
+++ b/docs/feature_wpm.md
@@ -16,7 +16,7 @@ For split keyboards using soft serial, the computed WPM score will be available
| `WPM_ALLOW_COUNT_REGRESSION` | _Not defined_ | If defined allows the WPM to be decreased when hitting Delete or Backspace |
| `WPM_UNFILTERED` | _Not defined_ | If undefined (the default), WPM values will be smoothed to avoid sudden changes in value |
| `WPM_SAMPLE_SECONDS` | `5` | This defines how many seconds of typing to average, when calculating WPM |
-| `WPM_SAMPLE_PERIODS` | `50` | This defines how many sampling periods to use when calculating WPM |
+| `WPM_SAMPLE_PERIODS` | `25` | This defines how many sampling periods to use when calculating WPM |
| `WPM_LAUNCH_CONTROL` | _Not defined_ | If defined, WPM values will be calculated using partial buffers when typing begins |
'WPM_UNFILTERED' is potentially useful if you're filtering data in some other way (and also because it reduces the code required for the WPM feature), or if reducing measurement latency to a minimum is important for you.
diff --git a/quantum/wpm.c b/quantum/wpm.c
index 925e2c416e..62d4128b8e 100644
--- a/quantum/wpm.c
+++ b/quantum/wpm.c
@@ -22,33 +22,37 @@
// WPM Stuff
static uint8_t current_wpm = 0;
static uint32_t wpm_timer = 0;
-#ifndef WPM_UNFILTERED
-static uint32_t smoothing_timer = 0;
-#endif
/* The WPM calculation works by specifying a certain number of 'periods' inside
* a ring buffer, and we count the number of keypresses which occur in each of
* those periods. Then to calculate WPM, we add up all of the keypresses in
* the whole ring buffer, divide by the number of keypresses in a 'word', and
- * then adjust for how much time is captured by our ring buffer. Right now
- * the ring buffer is hardcoded below to be six half-second periods, accounting
- * for a total WPM sampling period of up to three seconds of typing.
+ * then adjust for how much time is captured by our ring buffer. The size
+ * of the ring buffer can be configured using the keymap configuration
+ * value `WPM_SAMPLE_PERIODS`.
*
- * Whenever our WPM drops to absolute zero due to no typing occurring within
- * any contiguous three seconds, we reset and start measuring fresh,
- * which lets our WPM immediately reach the correct value even before a full
- * three second sampling buffer has been filled.
*/
#define MAX_PERIODS (WPM_SAMPLE_PERIODS)
#define PERIOD_DURATION (1000 * WPM_SAMPLE_SECONDS / MAX_PERIODS)
-#define LATENCY (100)
-static int8_t period_presses[MAX_PERIODS] = {0};
+
+static int16_t period_presses[MAX_PERIODS] = {0};
static uint8_t current_period = 0;
static uint8_t periods = 1;
#if !defined(WPM_UNFILTERED)
-static uint8_t prev_wpm = 0;
-static uint8_t next_wpm = 0;
+/* LATENCY is used as part of filtering, and controls how quickly the reported
+ * WPM trails behind our actual instantaneous measured WPM value, and is
+ * defined in milliseconds. So for LATENCY == 100, the displayed WPM is
+ * smoothed out over periods of 0.1 seconds. This results in a nice,
+ * smoothly-moving reported WPM value which nevertheless is never more than
+ * 0.1 seconds behind the typist's actual current WPM.
+ *
+ * LATENCY is not used if WPM_UNFILTERED is defined.
+ */
+# define LATENCY (100)
+static uint32_t smoothing_timer = 0;
+static uint8_t prev_wpm = 0;
+static uint8_t next_wpm = 0;
#endif
void set_current_wpm(uint8_t new_wpm) { current_wpm = new_wpm; }
@@ -71,7 +75,7 @@ __attribute__((weak)) bool wpm_keycode_user(uint16_t keycode) {
return false;
}
-#ifdef WPM_ALLOW_COUNT_REGRESSION
+#if defined(WPM_ALLOW_COUNT_REGRESSION)
__attribute__((weak)) uint8_t wpm_regress_count(uint16_t keycode) {
bool weak_modded = (keycode >= QK_LCTL && keycode < QK_LSFT) || (keycode >= QK_RCTL && keycode < QK_RSFT);
@@ -95,12 +99,12 @@ __attribute__((weak)) uint8_t wpm_regress_count(uint16_t keycode) {
// Outside 'raw' mode we smooth results over time.
void update_wpm(uint16_t keycode) {
- if (wpm_keycode(keycode)) {
+ if (wpm_keycode(keycode) && period_presses[current_period] < INT16_MAX) {
period_presses[current_period]++;
}
-#ifdef WPM_ALLOW_COUNT_REGRESSION
+#if defined(WPM_ALLOW_COUNT_REGRESSION)
uint8_t regress = wpm_regress_count(keycode);
- if (regress) {
+ if (regress && period_presses[current_period] > INT16_MIN) {
period_presses[current_period]--;
}
#endif
@@ -116,32 +120,41 @@ void decay_wpm(void) {
}
int32_t elapsed = timer_elapsed32(wpm_timer);
uint32_t duration = (((periods)*PERIOD_DURATION) + elapsed);
- uint32_t wpm_now = (60000 * presses) / (duration * WPM_ESTIMATED_WORD_SIZE);
- wpm_now = (wpm_now > 240) ? 240 : wpm_now;
+ int32_t wpm_now = (60000 * presses) / (duration * WPM_ESTIMATED_WORD_SIZE);
+
+ if (wpm_now < 0) // set some reasonable WPM measurement limits
+ wpm_now = 0;
+ if (wpm_now > 240) wpm_now = 240;
if (elapsed > PERIOD_DURATION) {
current_period = (current_period + 1) % MAX_PERIODS;
period_presses[current_period] = 0;
periods = (periods < MAX_PERIODS - 1) ? periods + 1 : MAX_PERIODS - 1;
elapsed = 0;
- /* if (wpm_timer == 0) { */
- wpm_timer = timer_read32();
- /* } else { */
- /* wpm_timer += PERIOD_DURATION; */
- /* } */
+ wpm_timer = timer_read32();
}
if (presses < 2) // don't guess high WPM based on a single keypress.
wpm_now = 0;
-#if defined WPM_LAUNCH_CONTROL
+#if defined(WPM_LAUNCH_CONTROL)
+ /*
+ * If the `WPM_LAUNCH_CONTROL` option is enabled, then whenever our WPM
+ * drops to absolute zero due to no typing occurring within our sample
+ * ring buffer, we reset and start measuring fresh, which lets our WPM
+ * immediately reach the correct value even before a full sampling buffer
+ * has been filled.
+ */
if (presses == 0) {
- current_period = 0;
- periods = 0;
- wpm_now = 0;
+ current_period = 0;
+ periods = 0;
+ wpm_now = 0;
+ period_presses[0] = 0;
}
#endif // WPM_LAUNCH_CONTROL
-#ifndef WPM_UNFILTERED
+#if defined(WPM_UNFILTERED)
+ current_wpm = wpm_now;
+#else
int32_t latency = timer_elapsed32(smoothing_timer);
if (latency > LATENCY) {
smoothing_timer = timer_read32();
@@ -150,7 +163,5 @@ void decay_wpm(void) {
}
current_wpm = prev_wpm + (latency * ((int)next_wpm - (int)prev_wpm) / LATENCY);
-#else
- current_wpm = wpm_now;
#endif
}
diff --git a/quantum/wpm.h b/quantum/wpm.h
index c8e7d26684..305d75b450 100644
--- a/quantum/wpm.h
+++ b/quantum/wpm.h
@@ -26,7 +26,7 @@
# define WPM_SAMPLE_SECONDS 5
#endif
#ifndef WPM_SAMPLE_PERIODS
-# define WPM_SAMPLE_PERIODS 50
+# define WPM_SAMPLE_PERIODS 25
#endif
bool wpm_keycode(uint16_t keycode);