apps: Add temperature and humidity sensor example

This patch includes an example of how to monitor ambient
temperature and relative humidity using a DHT series sensor.

Signed-off-by: Luigi Luz <[email protected]>

apps/dht/CMakeLists.txt

@@ -0,0 +1,13 @@
+cmake_minimum_required(VERSION 3.8.2)
+
+if (NOT DEFINED ENV{KNOT_BASE})
+    message(FATAL_ERROR "Source the KNoT shell initialize script!")
+endif()
+
+include($ENV{KNOT_BASE}/core/CMakeLists.txt)
+project(KNoT_DHT)
+
+FILE(GLOB app_sources src/*.c)
+target_sources(app PRIVATE ${app_sources})
+
+include($ENV{ZEPHYR_BASE}/samples/net/common/common.cmake)

apps/dht/prj.conf

@@ -0,0 +1,20 @@
+# KNoT
+CONFIG_KNOT_NAME="KNoT DHT"
+CONFIG_KNOT_THING_DATA_MAX=2
+
+# Logging
+CONFIG_LOG=y
+CONFIG_LOG_IMMEDIATE=n
+CONFIG_LOG_PRINTK=y
+CONFIG_KNOT_LOG=y
+CONFIG_KNOT_LOG_LEVEL_DEBUG=y
+
+# Sensor
+CONFIG_SENSOR=y
+CONFIG_DHT=y
+CONFIG_DHT_GPIO_PIN_NUM=47
+# If using DHT22, comment DHT11 lines and uncomment DHT22 ones
+CONFIG_DHT_NAME="DHT11"
+#CONFIG_DHT_NAME="DHT22"
+CONFIG_DHT_CHIP_DHT11=y
+#CONFIG_DHT_CHIP_DHT22=y

apps/dht/setup.conf

@@ -0,0 +1 @@
+CONFIG_BT_DEVICE_NAME="KNoT DHT"

apps/dht/src/dht.c

@@ -0,0 +1,80 @@
+/* dht.c - KNoT Application Client */
+
+/*
+ * Copyright (c) 2019, CESAR. All rights reserved.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/*
+ * This example uses a DHT series sensor (DHT11/DHT22) to monitor ambient
+ * temperature and relative humidity. This example works for both DHT11 and
+ * DHT22 sensors, but it is configured by default for DHT11. If you want to
+ * use it with DHT22, change DHT_NAME and DHT_CHIP flags on prj.conf file.
+ */
+
+#include <zephyr.h>
+#include <net/net_core.h>
+#include <logging/log.h>
+#include <device.h>
+#include <sensor.h>
+
+#include "knot.h"
+#include <knot/knot_types.h>
+#include <knot/knot_protocol.h>
+
+LOG_MODULE_REGISTER(dht, LOG_LEVEL_DBG);
+
+struct device *dev;
+int temperature, relative_humidity;
+
+/* Get temperature values from DHT sensor*/
+int on_get_temperature(int id)
+{
+	struct sensor_value temp;
+
+	sensor_channel_get(dev, SENSOR_CHAN_AMBIENT_TEMP, &temp);
+	temperature = temp.val1;
+	LOG_INF("Temperature value: %d \n", temperature);
+
+	return KNOT_CALLBACK_SUCCESS;
+}
+
+/* Get relative humidity values from DHT sensor*/
+int on_get_humidity(int id)
+{
+	struct sensor_value humidity;
+
+	sensor_channel_get(dev, SENSOR_CHAN_HUMIDITY, &humidity);
+	relative_humidity = humidity.val1;
+	LOG_INF("Relative humidity value: %d \n", relative_humidity);
+
+	return KNOT_CALLBACK_SUCCESS;
+}
+
+void setup(void)
+{
+	/* Peripherals control */
+	dev = device_get_binding(CONFIG_DHT_NAME);
+	if (dev == NULL) {
+		LOG_ERR("Could not get DHT device\n");
+		}
+	/* KNoT config */
+	knot_data_register(0, "TEMPERATURE", KNOT_TYPE_ID_TEMPERATURE,
+				KNOT_VALUE_TYPE_INT, KNOT_UNIT_TEMPERATURE_C,
+				&temperature, sizeof(temperature),
+				 NULL, on_get_temperature);
+	knot_data_config(0, KNOT_EVT_FLAG_TIME, 10, NULL);
+	knot_data_register(1, "RELATIVE HUMIDITY",
+				KNOT_TYPE_ID_RELATIVE_HUMIDITY,
+				KNOT_VALUE_TYPE_INT,
+				KNOT_UNIT_RELATIVE_HUMIDITY,
+				&relative_humidity,
+				sizeof(relative_humidity),
+				NULL, on_get_humidity);
+	knot_data_config(1, KNOT_EVT_FLAG_TIME, 10, NULL);
+}
+
+void loop(void)
+{
+}