samples: sensor: accel_trig: add sample with double tap detection.

Add the tap detection trigger to the existing example.
For this example it uses lis2dw12 accelerometer to detect a double
tap.

Signed-off-by: Pierrick Curt <pierrickcurt@gmail.com>

samples/sensor/accel_trig/README.rst

@@ -7,6 +7,10 @@ Overview
 ********
 
 This sample application demonstrates how to use 3-Axis accelerometers with triggers.
+By defaut it uses a data ready trigger to read the accelerometer data and print it to the console.
+
+If the accelerometer is enabled with a tap trigger, the sample uses the tap trigger event to
+read the accelerometer data and print it to the console.
 
 Building and Running
 ********************
@@ -27,8 +31,8 @@ Make sure the aliases are in devicetree, then build and run with:
    :goals: build flash
    :compact:
 
-Sample Output
-=============
+Sample Output (SENSOR_TRIG_DATA_READY)
+=======================================
 
 .. code-block:: console
 
@@ -43,3 +47,28 @@ Sample Output
      fxos8700@1d [m/s^2]:    (   -0.105345,    -0.028731,     9.921571)
      fxos8700@1d [m/s^2]:    (   -0.095769,    -0.028731,     9.931148)
      fxos8700@1d [m/s^2]:    (   -0.095769,    -0.009577,     9.940725)
+
+
+Sample Output (SENSOR_TRIG_DOUBLE_TAP)
+======================================
+
+.. code-block:: console
+
+  TAP detected
+     lis2dw12@19 [m/s^2]:    (   -1.899901,   -12.550355,    -2.742174)
+  TAP detected
+     lis2dw12@19 [m/s^2]:    (   12.349357,   -18.125630,     6.015556)
+  TAP detected
+     lis2dw12@19 [m/s^2]:    (  -11.385050,    -7.274181,    -9.229117)
+  TAP detected
+     lis2dw12@19 [m/s^2]:    (    9.214760,    -9.286545,     2.311466)
+  TAP detected
+     lis2dw12@19 [m/s^2]:    (   10.090533,   -17.391034,    12.320643)
+  TAP detected
+     lis2dw12@19 [m/s^2]:    (   -0.478564,     2.390429,    15.876378)
+  TAP detected
+     lis2dw12@19 [m/s^2]:    (   -5.668596,   -13.138989,     0.741775)
+  TAP detected
+     lis2dw12@19 [m/s^2]:    (   -2.385644,   -10.559526,     9.899107)
+  TAP detected
+     lis2dw12@19 [m/s^2]:    (    7.537391,    -8.551948,    16.740187)

samples/sensor/accel_trig/boards/stm32f3_disco.conf

@@ -0,0 +1,4 @@
+CONFIG_I2C=y
+CONFIG_SENSOR_LOG_LEVEL_DBG=y
+CONFIG_LIS2DW12_TRIGGER_GLOBAL_THREAD=y
+CONFIG_LIS2DW12_TAP=y

samples/sensor/accel_trig/boards/stm32f3_disco.overlay

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2024, Pierrick Curt.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/dt-bindings/sensor/lis2dw12.h>
+
+/ {
+	aliases {
+		accel0 = &lis2dw12_accel;
+	};
+};
+
+&i2c2 {
+	pinctrl-0 = <&i2c2_scl_pa9 &i2c2_sda_pa10>;
+	pinctrl-names = "default";
+	status = "okay";
+	clock-frequency = <I2C_BITRATE_FAST>;
+
+	lis2dw12_accel: lis2dw12@19 {
+		compatible = "st,lis2dw12";
+		reg = <0x19>;
+		odr = <400>;
+		tap-mode = <LIS2DW12_DT_SINGLE_DOUBLE_TAP>;
+		tap-threshold = <12>, <12>, <12>;
+		power-mode = <LIS2DW12_DT_HP_MODE>;
+		tap-shock = <0x03>;
+		tap-quiet = <0x03>;
+		tap-latency = <0x03>;
+		irq-gpios = <&gpioe 6 GPIO_ACTIVE_HIGH>;
+	};
+};

samples/sensor/accel_trig/src/main.c

@@ -11,6 +11,19 @@
 
 K_SEM_DEFINE(sem, 0, 1); /* starts off "not available" */
 
+#if DT_NODE_HAS_PROP(DT_ALIAS(accel0), tap_mode)
+static void tap_trigger_handler(const struct device *dev, const struct sensor_trigger *trigger)
+{
+	ARG_UNUSED(trigger);
+	printf("TAP detected\n");
+
+	if (sensor_sample_fetch_chan(dev, SENSOR_CHAN_ACCEL_XYZ) < 0) {
+		printf("ERROR: SENSOR_CHAN_ACCEL_XYZ fetch failed\n");
+	}
+
+	k_sem_give(&sem);
+}
+#else
 static void trigger_handler(const struct device *dev, const struct sensor_trigger *trigger)
 {
 	ARG_UNUSED(trigger);
@@ -25,6 +38,7 @@ static void trigger_handler(const struct device *dev, const struct sensor_trigge
 
 	k_sem_give(&sem);
 }
+#endif
 
 int main(void)
 {
@@ -41,10 +55,19 @@ int main(void)
 		return 0;
 	}
 
+#if DT_NODE_HAS_PROP(DT_ALIAS(accel0), tap_mode)
+	trig.type = SENSOR_TRIG_DOUBLE_TAP;
+	trig.chan = SENSOR_CHAN_ACCEL_XYZ;
+	if (sensor_trigger_set(dev, &trig, tap_trigger_handler) < 0) {
+		printf("Could not set tap trigger\n");
+		return 0;
+	}
+#else
 	if (sensor_trigger_set(dev, &trig, trigger_handler)) {
 		printf("Could not set trigger\n");
 		return 0;
 	}
+#endif
 
 	while (1) {
 		k_sem_take(&sem, K_FOREVER);