From eaae42cca99c84ace0cd8d2cf3989725bc56eef7 Mon Sep 17 00:00:00 2001
From: David Volovskiy <devolov@gmail.com>
Date: Sat, 15 Nov 2025 12:47:53 -0500
Subject: [PATCH] Added double-tap capabilities to LIS2DW

---
 movement.c                           |  6 ++++--
 watch-library/shared/driver/lis2dw.c | 14 ++++++++++++++
 watch-library/shared/driver/lis2dw.h |  4 ++++
 3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/movement.c b/movement.c
index ca0b0f36..5f2c5475 100644
--- a/movement.c
+++ b/movement.c
@@ -516,18 +516,19 @@ bool movement_enable_tap_detection_if_available(void) {
     if (movement_state.has_lis2dw) {
         // configure tap duration threshold and enable Z axis
         lis2dw_configure_tap_threshold(0, 0, 12, LIS2DW_REG_TAP_THS_Z_Z_AXIS_ENABLE);
-        lis2dw_configure_tap_duration(10, 2, 2);
+        lis2dw_configure_tap_duration(2, 2, 2);
 
         // ramp data rate up to 400 Hz and high performance mode
         lis2dw_set_low_noise_mode(true);
         lis2dw_set_data_rate(LIS2DW_DATA_RATE_HP_400_HZ);
         lis2dw_set_mode(LIS2DW_MODE_HIGH_PERFORMANCE);
+        lis2dw_enable_double_tap();
 
         // Settling time (1 sample duration, i.e. 1/400Hz)
         delay_ms(3);
 
         // enable tap detection on INT1/A3.
-        lis2dw_configure_int1(LIS2DW_CTRL4_INT1_SINGLE_TAP | LIS2DW_CTRL4_INT1_6D);
+        lis2dw_configure_int1(LIS2DW_CTRL4_INT1_SINGLE_TAP | LIS2DW_CTRL4_INT1_DOUBLE_TAP | LIS2DW_CTRL4_INT1_6D);
 
         return true;
     }
@@ -541,6 +542,7 @@ bool movement_disable_tap_detection_if_available(void) {
         lis2dw_set_low_noise_mode(false);
         lis2dw_set_data_rate(movement_state.accelerometer_background_rate);
         lis2dw_set_mode(LIS2DW_MODE_LOW_POWER);
+        lis2dw_disable_double_tap();
         // ...disable Z axis (not sure if this is needed, does this save power?)...
         lis2dw_configure_tap_threshold(0, 0, 0, 0);
 
diff --git a/watch-library/shared/driver/lis2dw.c b/watch-library/shared/driver/lis2dw.c
index b716f790..1c89f244 100644
--- a/watch-library/shared/driver/lis2dw.c
+++ b/watch-library/shared/driver/lis2dw.c
@@ -302,6 +302,20 @@ void lis2dw_clear_fifo(void) {
 #endif
 }
 
+void lis2dw_enable_double_tap(void) {
+#ifdef I2C_SERCOM
+    uint8_t configuration = watch_i2c_read8(LIS2DW_ADDRESS, LIS2DW_REG_WAKE_UP_THS);
+    watch_i2c_write8(LIS2DW_ADDRESS, LIS2DW_REG_WAKE_UP_THS, configuration | LIS2DW_WAKE_UP_THS_ENABLE_DOUBLE_TAP);
+#endif
+}
+
+void lis2dw_disable_double_tap(void) {
+#ifdef I2C_SERCOM
+    uint8_t configuration = watch_i2c_read8(LIS2DW_ADDRESS, LIS2DW_REG_WAKE_UP_THS);
+    watch_i2c_write8(LIS2DW_ADDRESS, LIS2DW_REG_WAKE_UP_THS, configuration & ~LIS2DW_WAKE_UP_THS_ENABLE_DOUBLE_TAP);
+#endif
+}
+
 void lis2dw_enable_sleep(void) {
 #ifdef I2C_SERCOM
     uint8_t configuration = watch_i2c_read8(LIS2DW_ADDRESS, LIS2DW_REG_WAKE_UP_THS);
diff --git a/watch-library/shared/driver/lis2dw.h b/watch-library/shared/driver/lis2dw.h
index 57ff05b2..3b017c65 100644
--- a/watch-library/shared/driver/lis2dw.h
+++ b/watch-library/shared/driver/lis2dw.h
@@ -343,6 +343,10 @@ bool lis2dw_read_fifo(lis2dw_fifo_t *fifo_data);
 
 void lis2dw_clear_fifo(void);
 
+void lis2dw_enable_double_tap(void);
+
+void lis2dw_disable_double_tap(void);
+
 void lis2dw_enable_sleep(void);
 
 void lis2dw_disable_sleep(void);