samples: sensors: isl29035: add sample

Add a sample to demonstrate and test the Renesas/Intersil ISL29035
light sensor driver.

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

samples/sensor/isl29035/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(isl29035)
+
+FILE(GLOB app_sources src/*.c)
+target_sources(app PRIVATE ${app_sources})

samples/sensor/isl29035/README.rst

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+.. _isl29035:
+
+ISL29035: Digital Light Sensor
+##############################
+
+Overview
+********
+
+If trigger is not enabled the sample displays measured light intensity
+every 2 seconds.
+
+If trigger is enabled the sample displays light intensity from the
+ISL29035 sensor every 10 seconds if it is within +/- 50 lux of the last
+read sample.  If the sensor detects an intensity outside that range the
+application wakes, displays the intensity, resets the intensity range
+window to center on the new value, then continues as before.
+
+Requirements
+************
+
+This sample uses an external breakout for the sensor.  A devicetree
+overlay must be provided to connect the sensor to the I2C bus and
+identify the interrupt signal.
+
+Building and Running
+********************
+
+.. zephyr-app-commands::
+   :zephyr-app: samples/sensor/isl29035
+   :board: nrf52_pca10040
+   :goals: build
+   :compact:
+
+Sample Output
+=============
+
+.. code-block:: console
+
+   *** Booting Zephyr OS build zephyr-v2.1.0-335-gfe020d937d43  ***
+   ALERT 365 lux outside range centered on 0 lux.
+   Next alert outside 315 .. 415
+   [0:00:00.018] Ambient light sense: 365.234
+   [0:00:10.023] Ambient light sense: 361.084
+   ALERT 302 lux outside range centered on 365 lux.
+   Next alert outside 252 .. 352
+   [0:00:13.276] Ambient light sense: 302.734
+   ALERT 247 lux outside range centered on 302 lux.
+   Next alert outside 197 .. 297
+   [0:00:14.619] Ambient light sense: 247.62
+   ALERT 187 lux outside range centered on 247 lux.
+   Next alert outside 137 .. 237
+   [0:00:16.141] Ambient light sense: 187.927
+   ALERT 126 lux outside range centered on 187 lux.
+   Next alert outside 76 .. 176
+   [0:00:16.410] Ambient light sense: 126.953
+   ALERT 181 lux outside range centered on 126 lux.
+   Next alert outside 131 .. 231
+   [0:00:17.843] Ambient light sense: 181.03
+   ALERT 235 lux outside range centered on 181 lux.
+   Next alert outside 185 .. 285
+   [0:00:18.022] Ambient light sense: 235.779
+   ALERT 301 lux outside range centered on 235 lux.
+   Next alert outside 251 .. 351
+   [0:00:23.126] Ambient light sense: 301.758
+   ALERT 353 lux outside range centered on 301 lux.
+   Next alert outside 303 .. 403
+   [0:00:23.305] Ambient light sense: 353.333
+   [0:00:33.310] Ambient light sense: 365.112
+
+   <repeats as necessary>

samples/sensor/isl29035/boards/nrf52_pca10040.overlay

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+/*
+ * Copyright (c) 2019 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+&i2c0 { /* SDA P0.26, SCL P0.27, ALERT P1.11 */
+	isl29035@44 {
+		compatible = "isil,isl29035";
+		reg = <0x44>;
+		label = "ISL29035";
+		int-gpios = <&gpio0 11 GPIO_INT_ACTIVE_HIGH>;
+	};
+};

samples/sensor/isl29035/prj.conf

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+CONFIG_STDOUT_CONSOLE=y
+CONFIG_I2C=y
+CONFIG_SENSOR=y
+CONFIG_ISL29035=y
+CONFIG_ISL29035_TRIGGER_GLOBAL_THREAD=y
+CONFIG_ISL29035_LUX_RANGE_4K=y

samples/sensor/isl29035/sample.yaml

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+sample:
+  name: ISL29035 Digital Light Sensor
+tests:
+  sample.sensor.isl29035:
+    harness: console
+    tags: sensors
+    depends_on: i2c
+    platform_whitelist: nrf52_pca10040

samples/sensor/isl29035/src/main.c

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+/*
+ * 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>
+
+#define LUX_ALERT_DELTA 50
+
+static volatile bool alerted;
+struct k_sem sem;
+
+#ifdef CONFIG_ISL29035_TRIGGER
+static void trigger_handler(struct device *dev,
+			    struct sensor_trigger *trig)
+{
+	alerted = !alerted;
+	k_sem_give(&sem);
+}
+#endif /* CONFIG_ISL29035_TRIGGER */
+
+static const char *now_str(void)
+{
+	static char buf[16]; /* ...HH:MM:SS.MMM */
+	u32_t now = k_uptime_get_32();
+	unsigned int ms = now % MSEC_PER_SEC;
+	unsigned int s;
+	unsigned int min;
+	unsigned int h;
+
+	now /= MSEC_PER_SEC;
+	s = now % 60U;
+	now /= 60U;
+	min = now % 60U;
+	now /= 60U;
+	h = now;
+
+	snprintf(buf, sizeof(buf), "%u:%02u:%02u.%03u",
+		 h, min, s, ms);
+	return buf;
+}
+
+static void process_sample(struct device *dev)
+{
+	static bool last_alerted;
+	struct sensor_value val;
+
+	if (sensor_sample_fetch(dev) < 0) {
+		printf("Sensor sample update error\n");
+		return;
+	}
+
+	if (sensor_channel_get(dev, SENSOR_CHAN_LIGHT, &val) < 0) {
+		printf("Cannot read ISL29035 value\n");
+		return;
+	}
+
+	int lux = val.val1;
+
+	if (IS_ENABLED(CONFIG_ISL29035_TRIGGER)
+	    && (alerted != last_alerted)) {
+		static int last_lux;
+		int rc;
+		struct sensor_trigger trig = {
+			.type = SENSOR_TRIG_THRESHOLD,
+			.chan = SENSOR_CHAN_ALL,
+		};
+		struct sensor_value lo_thr = { MAX(lux - LUX_ALERT_DELTA, 0), };
+		struct sensor_value hi_thr = { lux + LUX_ALERT_DELTA };
+
+		printf("ALERT %d lux outside range centered on %d lux."
+		       "\nNext alert outside %d .. %d\n",
+		       lux, last_lux, lo_thr.val1, hi_thr.val1);
+		last_lux = lux;
+		last_alerted = alerted;
+
+		rc = sensor_attr_set(dev, SENSOR_CHAN_LIGHT,
+				     SENSOR_ATTR_LOWER_THRESH, &lo_thr);
+		if (rc == 0) {
+			rc = sensor_attr_set(dev, SENSOR_CHAN_LIGHT,
+					     SENSOR_ATTR_UPPER_THRESH, &hi_thr);
+		}
+		if (rc == 0) {
+			rc = sensor_trigger_set(dev, &trig, trigger_handler);
+		}
+		if (rc != 0) {
+			printf("Alert configuration failed: %d\n", rc);
+		}
+	}
+
+	printf("[%s] %s: %g\n", now_str(),
+	       IS_ENABLED(CONFIG_ISL29035_MODE_ALS)
+	       ? "Ambient light sense"
+	       : "IR sense",
+	       sensor_value_to_double(&val));
+}
+
+void main(void)
+{
+	struct device *dev = device_get_binding("ISL29035");
+
+	if (dev == NULL) {
+		printf("Could not get ISL29035 device\n");
+		return;
+	}
+
+	k_sem_init(&sem, 0, 1);
+	alerted = true;
+	while (true) {
+		process_sample(dev);
+
+		if (IS_ENABLED(CONFIG_ISL29035_TRIGGER)) {
+			k_sem_take(&sem, K_SECONDS(10));
+		} else {
+			k_sleep(K_SECONDS(1));
+		}
+	}
+}