samples: sensor: lps22hh: add standalone sample

Although this sensor is demonstrated by the X-NUCLEO-IKS01A3 sample,
maintenance of the driver is simplified if it can be tested in
isolation.  Provide a sample modeled on hts221.

Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>

samples/sensor/lps22hh/CMakeLists.txt

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+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.13.1)
+include($ENV{ZEPHYR_BASE}/cmake/app/boilerplate.cmake NO_POLICY_SCOPE)
+project(lps22hh)
+
+FILE(GLOB app_sources src/*.c)
+target_sources(app PRIVATE ${app_sources})

samples/sensor/lps22hh/README.rst

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+.. _lps22hh:
+
+LPS22HH: Temperature and Pressure Monitor
+#########################################
+
+Overview
+********
+This sample periodically reads pressure from the LPS22HH MEMS pressure
+sensor and displays it on the console.
+
+
+Requirements
+************
+
+This sample uses the LPS22HH sensor controlled using the I2C interface.
+
+References
+**********
+
+- LPS22HH: http://www.st.com/en/mems-and-sensors/lps22hh.html
+
+Building and Running
+********************
+
+This project outputs sensor data to the console. It requires an LPS22HH
+sensor, which is present on the X-NUCLEO-IKS01A3 shield.
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/sensor/lps22hh
+   :board: nrf52_pca10040
+   :shield: x_nucleo_iks01a3
+   :goals: build
+   :compact:
+
+Sample Output
+=============
+
+.. code-block:: console
+
+   Configured for triggered collection at 1 Hz
+   Observation: 1
+   Pressure: 97.474 kPa
+   Temperature: 22.19 C
+   Observation: 2
+   Pressure: 97.466 kPa
+   Temperature: 22.21 C
+   Observation: 3
+   Pressure: 97.473 kPa
+   Temperature: 22.21 C
+   Observation: 4
+   Pressure: 97.455 kPa
+   Temperature: 22.21 C
+
+   <repeats endlessly every second>

samples/sensor/lps22hh/prj.conf

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+CONFIG_STDOUT_CONSOLE=y
+CONFIG_I2C=y
+CONFIG_SENSOR=y
+CONFIG_LPS22HH=y

samples/sensor/lps22hh/sample.yaml

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+sample:
+  name: LPS22HH Temperature and Pressure Monitor
+tests:
+  sample.sensor.lps22hh.nrf52.iks01a3:
+    harness: console
+    platform_whitelist: nrf52_pca10040
+    tags: sensors
+    depends_on: i2c
+    extra_args: SHIELD=x_nucleo_iks01a3
+    harness_config:
+        type: multi_line
+        ordered: yes
+        regex:
+            - "Temperature: (.*)"
+            - "Pressure: (.*)"

samples/sensor/lps22hh/src/main.c

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+/*
+ * Copyright (c) 2017 Linaro Limited
+ * Copyright (c) 2019 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr.h>
+#include <device.h>
+#include <drivers/sensor.h>
+#include <stdio.h>
+#include <sys/util.h>
+
+static void process_sample(struct device *dev)
+{
+	static unsigned int obs;
+	struct sensor_value pressure, temp;
+
+	if (sensor_sample_fetch(dev) < 0) {
+		printf("Sensor sample update error\n");
+		return;
+	}
+
+	if (sensor_channel_get(dev, SENSOR_CHAN_PRESS, &pressure) < 0) {
+		printf("Cannot read LPS22HH pressure channel\n");
+		return;
+	}
+
+	if (sensor_channel_get(dev, SENSOR_CHAN_AMBIENT_TEMP, &temp) < 0) {
+		printf("Cannot read LPS22HH temperature channel\n");
+		return;
+	}
+
+	++obs;
+	printf("Observation: %u\n", obs);
+
+	/* display pressure */
+	printf("Pressure: %.3f kPa\n", sensor_value_to_double(&pressure));
+
+	/* display temperature */
+	printf("Temperature: %.2f C\n", sensor_value_to_double(&temp));
+
+}
+
+static void lps22hh_handler(struct device *dev,
+			   struct sensor_trigger *trig)
+{
+	process_sample(dev);
+}
+
+void main(void)
+{
+	struct device *dev = device_get_binding("LPS22HH");
+
+	if (dev == NULL) {
+		printf("Could not get LPS22HH device\n");
+		return;
+	}
+
+	if (IS_ENABLED(CONFIG_LPS22HH_TRIGGER)) {
+		struct sensor_value attr = {
+			.val1 = 1,
+		};
+		struct sensor_trigger trig = {
+			.type = SENSOR_TRIG_DATA_READY,
+			.chan = SENSOR_CHAN_ALL,
+		};
+
+		if (sensor_attr_set(dev, SENSOR_CHAN_ALL,
+				    SENSOR_ATTR_SAMPLING_FREQUENCY, &attr) < 0) {
+			printf("Cannot configure sampling rate\n");
+			return;
+		}
+		if (sensor_trigger_set(dev, &trig, lps22hh_handler) < 0) {
+			printf("Cannot configure trigger\n");
+			return;
+		};
+		printk("Configured for triggered collection at %u Hz\n",
+		       attr.val1);
+	}
+
+	while (!IS_ENABLED(CONFIG_LPS22HH_TRIGGER)) {
+		process_sample(dev);
+		k_sleep(K_MSEC(2000));
+	}
+	k_sleep(K_FOREVER);
+}