samples/bluetooth/peripheral_esp/src/main.c - third_party/github/zephyrproject-rtos/zephyr - Git at Google

 /* main.c - Application main entry point */

 /*
  * Copyright (c) 2016 Intel Corporation
  *
  * SPDX-License-Identifier: Apache-2.0
  */

 #include <stdbool.h>
 #include <stdint.h>
 #include <stddef.h>
 #include <string.h>
 #include <errno.h>
 #include <misc/printk.h>
 #include <misc/byteorder.h>
 #include <zephyr.h>

 #include <bluetooth/bluetooth.h>
 #include <bluetooth/hci.h>
 #include <bluetooth/conn.h>
 #include <bluetooth/uuid.h>
 #include <bluetooth/gatt.h>

 #include <gatt/gap.h>
 #include <gatt/dis.h>
 #include <gatt/bas.h>

 #define DEVICE_NAME				"ESP peripheral"
 #define DEVICE_NAME_LEN				(sizeof(DEVICE_NAME) - 1)
 #define SENSOR_1_NAME				"Temperature Sensor 1"
 #define SENSOR_2_NAME				"Temperature Sensor 2"
 #define SENSOR_3_NAME				"Humidity Sensor"
 #define APPEARANCE_THERMOMETER			0x0300

 /* Sensor Internal Update Interval [seconds] */
 #define SENSOR_1_UPDATE_IVAL			5
 #define SENSOR_2_UPDATE_IVAL			12
 #define SENSOR_3_UPDATE_IVAL			60

 /* ESS error definitions */
 #define ESS_ERR_WRITE_REJECT			0x80
 #define ESS_ERR_COND_NOT_SUPP			0x81

 /* ESS Trigger Setting conditions */
 #define ESS_TRIGGER_INACTIVE			0x00
 #define ESS_FIXED_TIME_INTERVAL			0x01
 #define ESS_NO_LESS_THAN_SPECIFIED_TIME		0x02
 #define ESS_VALUE_CHANGED			0x03
 #define ESS_LESS_THAN_REF_VALUE			0x04
 #define ESS_LESS_OR_EQUAL_TO_REF_VALUE		0x05
 #define ESS_GREATER_THAN_REF_VALUE		0x06
 #define ESS_GREATER_OR_EQUAL_TO_REF_VALUE	0x07
 #define ESS_EQUAL_TO_REF_VALUE			0x08
 #define ESS_NOT_EQUAL_TO_REF_VALUE		0x09

 static inline void int_to_le24(uint32_t value, uint8_t *u24)
 {
 	u24[0] = value & 0xff;
 	u24[1] = (value >> 8) & 0xff;
 	u24[2] = (value >> 16) & 0xff;
 }

 static inline uint32_t le24_to_int(const uint8_t *u24)
 {
 	return ((uint32_t)u24[0] |
 		(uint32_t)u24[1] << 8 |
 		(uint32_t)u24[2] << 16);
 }

 static ssize_t read_u16(struct bt_conn *conn, const struct bt_gatt_attr *attr,
 			void *buf, uint16_t len, uint16_t offset)
 {
 	const uint16_t *u16 = attr->user_data;
 	uint16_t value = sys_cpu_to_le16(*u16);

 	return bt_gatt_attr_read(conn, attr, buf, len, offset, &value,
 				 sizeof(value));
 }

 /* Environmental Sensing Service Declaration */

 struct es_measurement {
 	uint16_t flags; /* Reserved for Future Use */
 	uint8_t sampling_func;
 	uint32_t meas_period;
 	uint32_t update_interval;
 	uint8_t application;
 	uint8_t meas_uncertainty;
 };

 struct temperature_sensor {
 	int16_t temp_value;

 	/* Valid Range */
 	int16_t lower_limit;
 	int16_t upper_limit;

 	/* ES trigger setting - Value Notification condition */
 	uint8_t condition;
 	union {
 		uint32_t seconds;
 		int16_t ref_val; /* Reference temperature */
 	};

 	struct bt_gatt_ccc_cfg  ccc_cfg[CONFIG_BLUETOOTH_MAX_PAIRED];
 	struct es_measurement meas;
 };

 struct humidity_sensor {
 	int16_t humid_value;

 	struct es_measurement meas;
 };

 static bool simulate_temp;
 static struct temperature_sensor sensor_1 = {
 		.temp_value = 1200,
 		.lower_limit = -10000,
 		.upper_limit = 10000,
 		.condition = ESS_VALUE_CHANGED,
 		.meas.sampling_func = 0x00,
 		.meas.meas_period = 0x01,
 		.meas.update_interval = SENSOR_1_UPDATE_IVAL,
 		.meas.application = 0x1c,
 		.meas.meas_uncertainty = 0x04,
 };

 static struct temperature_sensor sensor_2 = {
 		.temp_value = 1800,
 		.lower_limit = -1000,
 		.upper_limit = 5000,
 		.condition = ESS_VALUE_CHANGED,
 		.meas.sampling_func = 0x00,
 		.meas.meas_period = 0x01,
 		.meas.update_interval = SENSOR_2_UPDATE_IVAL,
 		.meas.application = 0x1b,
 		.meas.meas_uncertainty = 0x04,
 };

 static struct humidity_sensor sensor_3 = {
 		.humid_value = 6233,
 		.meas.sampling_func = 0x02,
 		.meas.meas_period = 0x0e10,
 		.meas.update_interval = SENSOR_3_UPDATE_IVAL,
 		.meas.application = 0x1c,
 		.meas.meas_uncertainty = 0x01,
 };

 static void temp_ccc_cfg_changed(const struct bt_gatt_attr *attr,
 				 uint16_t value)
 {
 	simulate_temp = value == BT_GATT_CCC_NOTIFY;
 }

 struct read_es_measurement_rp {
 	uint16_t flags; /* Reserved for Future Use */
 	uint8_t sampling_function;
 	uint8_t measurement_period[3];
 	uint8_t update_interval[3];
 	uint8_t application;
 	uint8_t measurement_uncertainty;
 } __packed;

 static ssize_t read_es_measurement(struct bt_conn *conn,
 				   const struct bt_gatt_attr *attr, void *buf,
 				   uint16_t len, uint16_t offset)
 {
 	const struct es_measurement *value = attr->user_data;
 	struct read_es_measurement_rp rsp;

 	rsp.flags = sys_cpu_to_le16(value->flags);
 	rsp.sampling_function = value->sampling_func;
 	int_to_le24(value->meas_period, rsp.measurement_period);
 	int_to_le24(value->update_interval, rsp.update_interval);
 	rsp.application = value->application;
 	rsp.measurement_uncertainty = value->meas_uncertainty;

 	return bt_gatt_attr_read(conn, attr, buf, len, offset, &rsp,
 				 sizeof(rsp));
 }

 static ssize_t read_temp_valid_range(struct bt_conn *conn,
 				     const struct bt_gatt_attr *attr, void *buf,
 				     uint16_t len, uint16_t offset)
 {
 	const struct temperature_sensor *sensor = attr->user_data;
 	uint16_t tmp[] = {sys_cpu_to_le16(sensor->lower_limit),
 			  sys_cpu_to_le16(sensor->upper_limit)};

 	return bt_gatt_attr_read(conn, attr, buf, len, offset, tmp,
 				 sizeof(tmp));
 }

 struct es_trigger_setting_seconds {
 	uint8_t condition;
 	uint8_t sec[3];
 } __packed;

 struct es_trigger_setting_reference {
 	uint8_t condition;
 	int16_t ref_val;
 } __packed;

 static ssize_t read_temp_trigger_setting(struct bt_conn *conn,
 					 const struct bt_gatt_attr *attr,
 					 void *buf, uint16_t len,
 					 uint16_t offset)
 {
 	const struct temperature_sensor *sensor = attr->user_data;

 	switch (sensor->condition) {
 	/* Operand N/A */
 	case ESS_TRIGGER_INACTIVE:
 		/* fallthrough */
 	case ESS_VALUE_CHANGED:
 		return bt_gatt_attr_read(conn, attr, buf, len, offset,
 					 &sensor->condition,
 					 sizeof(sensor->condition));
 	/* Seconds */
 	case ESS_FIXED_TIME_INTERVAL:
 		/* fallthrough */
 	case ESS_NO_LESS_THAN_SPECIFIED_TIME: {
 			struct es_trigger_setting_seconds rp;

 			rp.condition = sensor->condition;
 			int_to_le24(sensor->seconds, rp.sec);

 			return bt_gatt_attr_read(conn, attr, buf, len, offset,
 						 &rp, sizeof(rp));
 		}
 	/* Reference temperature */
 	default: {
 			struct es_trigger_setting_reference rp;

 			rp.condition = sensor->condition;
 			rp.ref_val = sys_cpu_to_le16(sensor->ref_val);

 			return bt_gatt_attr_read(conn, attr, buf, len, offset,
 						 &rp, sizeof(rp));
 		}
 	}
 }

 static bool check_condition(uint8_t condition, int16_t old_val, int16_t new_val,
 			    int16_t ref_val)
 {
 	switch (condition) {
 	case ESS_TRIGGER_INACTIVE:
 		return false;
 	case ESS_FIXED_TIME_INTERVAL:
 	case ESS_NO_LESS_THAN_SPECIFIED_TIME:
 		/* TODO: Check time requirements */
 		return false;
 	case ESS_VALUE_CHANGED:
 		return new_val != old_val;
 	case ESS_LESS_THAN_REF_VALUE:
 		return new_val < ref_val;
 	case ESS_LESS_OR_EQUAL_TO_REF_VALUE:
 		return new_val <= ref_val;
 	case ESS_GREATER_THAN_REF_VALUE:
 		return new_val > ref_val;
 	case ESS_GREATER_OR_EQUAL_TO_REF_VALUE:
 		return new_val >= ref_val;
 	case ESS_EQUAL_TO_REF_VALUE:
 		return new_val == ref_val;
 	case ESS_NOT_EQUAL_TO_REF_VALUE:
 		return new_val != ref_val;
 	default:
 		return false;
 	}
 }

 static void update_temperature(struct bt_conn *conn,
 			       const struct bt_gatt_attr *chrc, int16_t value,
 			       struct temperature_sensor *sensor)
 {
 	bool notify = check_condition(sensor->condition,
 				      sensor->temp_value, value,
 				      sensor->ref_val);

 	/* Update temperature value */
 	sensor->temp_value = value;

 	/* Trigger notification if conditions are met */
 	if (notify) {
 		value = sys_cpu_to_le16(sensor->temp_value);

 		bt_gatt_notify(conn, chrc, &value, sizeof(value));
 	}
 }

 static struct bt_gatt_attr ess_attrs[] = {
 	BT_GATT_PRIMARY_SERVICE(BT_UUID_ESS),

 	/* Temperature Sensor 1 */
 	BT_GATT_CHARACTERISTIC(BT_UUID_TEMPERATURE,
 			       BT_GATT_CHRC_READ | BT_GATT_CHRC_NOTIFY),
 	BT_GATT_DESCRIPTOR(BT_UUID_TEMPERATURE, BT_GATT_PERM_READ,
 			   read_u16, NULL, &sensor_1.temp_value),
 	BT_GATT_DESCRIPTOR(BT_UUID_ES_MEASUREMENT, BT_GATT_PERM_READ,
 			   read_es_measurement, NULL, &sensor_1.meas),
 	BT_GATT_CUD(SENSOR_1_NAME, BT_GATT_PERM_READ),
 	BT_GATT_DESCRIPTOR(BT_UUID_VALID_RANGE, BT_GATT_PERM_READ,
 			   read_temp_valid_range, NULL, &sensor_1),
 	BT_GATT_DESCRIPTOR(BT_UUID_ES_TRIGGER_SETTING,
 			   BT_GATT_PERM_READ, read_temp_trigger_setting,
 			   NULL, &sensor_1),
 	BT_GATT_CCC(sensor_1.ccc_cfg, temp_ccc_cfg_changed),

 	/* Temperature Sensor 2 */
 	BT_GATT_CHARACTERISTIC(BT_UUID_TEMPERATURE,
 			       BT_GATT_CHRC_READ | BT_GATT_CHRC_NOTIFY),
 	BT_GATT_DESCRIPTOR(BT_UUID_TEMPERATURE, BT_GATT_PERM_READ,
 			   read_u16, NULL, &sensor_2.temp_value),
 	BT_GATT_DESCRIPTOR(BT_UUID_ES_MEASUREMENT, BT_GATT_PERM_READ,
 			   read_es_measurement, NULL, &sensor_2.meas),
 	BT_GATT_CUD(SENSOR_2_NAME, BT_GATT_PERM_READ),
 	BT_GATT_DESCRIPTOR(BT_UUID_VALID_RANGE, BT_GATT_PERM_READ,
 			   read_temp_valid_range, NULL, &sensor_2),
 	BT_GATT_DESCRIPTOR(BT_UUID_ES_TRIGGER_SETTING,
 			   BT_GATT_PERM_READ, read_temp_trigger_setting,
 			   NULL, &sensor_2),
 	BT_GATT_CCC(sensor_2.ccc_cfg, temp_ccc_cfg_changed),

 	/* Humidity Sensor */
 	BT_GATT_CHARACTERISTIC(BT_UUID_HUMIDITY, BT_GATT_CHRC_READ),
 	BT_GATT_DESCRIPTOR(BT_UUID_HUMIDITY, BT_GATT_PERM_READ,
 			   read_u16, NULL, &sensor_3.humid_value),
 	BT_GATT_CUD(SENSOR_3_NAME, BT_GATT_PERM_READ),
 	BT_GATT_DESCRIPTOR(BT_UUID_ES_MEASUREMENT, BT_GATT_PERM_READ,
 			   read_es_measurement, NULL, &sensor_3.meas),
 };

 static void ess_simulate(void)
 {
 	static uint8_t i;
 	uint16_t val;

 	if (!(i % SENSOR_1_UPDATE_IVAL)) {
 		val = 1200 + i;
 		update_temperature(NULL, &ess_attrs[2], val, &sensor_1);
 	}

 	if (!(i % SENSOR_2_UPDATE_IVAL)) {
 		val = 1800 + i;
 		update_temperature(NULL, &ess_attrs[9], val, &sensor_2);
 	}

 	if (!(i % SENSOR_3_UPDATE_IVAL)) {
 		sensor_3.humid_value = 6233 + (i % 13);
 	}

 	if (!(i % INT8_MAX)) {
 		i = 0;
 	}

 	i++;
 }

 static const struct bt_data ad[] = {
 	BT_DATA_BYTES(BT_DATA_FLAGS, (BT_LE_AD_GENERAL | BT_LE_AD_NO_BREDR)),
 	BT_DATA_BYTES(BT_DATA_GAP_APPEARANCE, 0x00, 0x03),
 	BT_DATA_BYTES(BT_DATA_UUID16_ALL, 0x1a, 0x18),
 	/* TODO: Include Service Data AD */
 };

 static struct bt_data sd[] = {
 	BT_DATA(BT_DATA_NAME_COMPLETE, DEVICE_NAME, DEVICE_NAME_LEN),
 };

 static void connected(struct bt_conn *conn, uint8_t err)
 {
 	if (err) {
 		printk("Connection failed (err %u)\n", err);
 	} else {
 		printk("Connected\n");
 	}
 }

 static void disconnected(struct bt_conn *conn, uint8_t reason)
 {
 	printk("Disconnected (reason %u)\n", reason);
 }

 static struct bt_conn_cb conn_callbacks = {
 	.connected = connected,
 	.disconnected = disconnected,
 };

 static void bt_ready(int err)
 {
 	if (err) {
 		printk("Bluetooth init failed (err %d)\n", err);
 		return;
 	}

 	printk("Bluetooth initialized\n");

 	gap_init(DEVICE_NAME, APPEARANCE_THERMOMETER);
 	bt_gatt_register(ess_attrs, ARRAY_SIZE(ess_attrs));
 	bas_init();
 	dis_init(CONFIG_SOC, "ACME");

 	err = bt_le_adv_start(BT_LE_ADV_CONN, ad, ARRAY_SIZE(ad),
 			      sd, ARRAY_SIZE(sd));
 	if (err) {
 		printk("Advertising failed to start (err %d)\n", err);
 		return;
 	}

 	printk("Advertising successfully started\n");
 }

 static void auth_passkey_display(struct bt_conn *conn, unsigned int passkey)
 {
 	char addr[BT_ADDR_LE_STR_LEN];

 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));

 	printk("Passkey for %s: %u\n", addr, passkey);
 }

 static void auth_cancel(struct bt_conn *conn)
 {
 	char addr[BT_ADDR_LE_STR_LEN];

 	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));

 	printk("Pairing cancelled: %s\n", addr);
 }

 static struct bt_conn_auth_cb auth_cb_display = {
 	.passkey_display = auth_passkey_display,
 	.passkey_entry = NULL,
 	.cancel = auth_cancel,
 };

 void main(void)
 {
 	int err;

 	err = bt_enable(bt_ready);
 	if (err) {
 		printk("Bluetooth init failed (err %d)\n", err);
 		return;
 	}

 	bt_conn_cb_register(&conn_callbacks);
 	bt_conn_auth_cb_register(&auth_cb_display);

 	while (1) {
 		k_sleep(MSEC_PER_SEC);

 		/* Temperature simulation */
 		if (simulate_temp) {
 			ess_simulate();
 		}

 		/* Battery level simulation */
 		bas_notify();
 	}
 }
	/* main.c - Application main entry point */

	/*
	* Copyright (c) 2016 Intel Corporation
	*
	* SPDX-License-Identifier: Apache-2.0
	*/

	#include <stdbool.h>
	#include <stdint.h>
	#include <stddef.h>
	#include <string.h>
	#include <errno.h>
	#include <misc/printk.h>
	#include <misc/byteorder.h>
	#include <zephyr.h>

	#include <bluetooth/bluetooth.h>
	#include <bluetooth/hci.h>
	#include <bluetooth/conn.h>
	#include <bluetooth/uuid.h>
	#include <bluetooth/gatt.h>

	#include <gatt/gap.h>
	#include <gatt/dis.h>
	#include <gatt/bas.h>

	#define DEVICE_NAME "ESP peripheral"
	#define DEVICE_NAME_LEN (sizeof(DEVICE_NAME) - 1)
	#define SENSOR_1_NAME "Temperature Sensor 1"
	#define SENSOR_2_NAME "Temperature Sensor 2"
	#define SENSOR_3_NAME "Humidity Sensor"
	#define APPEARANCE_THERMOMETER 0x0300

	/* Sensor Internal Update Interval [seconds] */
	#define SENSOR_1_UPDATE_IVAL 5
	#define SENSOR_2_UPDATE_IVAL 12
	#define SENSOR_3_UPDATE_IVAL 60

	/* ESS error definitions */
	#define ESS_ERR_WRITE_REJECT 0x80
	#define ESS_ERR_COND_NOT_SUPP 0x81

	/* ESS Trigger Setting conditions */
	#define ESS_TRIGGER_INACTIVE 0x00
	#define ESS_FIXED_TIME_INTERVAL 0x01
	#define ESS_NO_LESS_THAN_SPECIFIED_TIME 0x02
	#define ESS_VALUE_CHANGED 0x03
	#define ESS_LESS_THAN_REF_VALUE 0x04
	#define ESS_LESS_OR_EQUAL_TO_REF_VALUE 0x05
	#define ESS_GREATER_THAN_REF_VALUE 0x06
	#define ESS_GREATER_OR_EQUAL_TO_REF_VALUE 0x07
	#define ESS_EQUAL_TO_REF_VALUE 0x08
	#define ESS_NOT_EQUAL_TO_REF_VALUE 0x09

	static inline void int_to_le24(uint32_t value, uint8_t *u24)
	{
	u24[0] = value & 0xff;
	u24[1] = (value >> 8) & 0xff;
	u24[2] = (value >> 16) & 0xff;
	}

	static inline uint32_t le24_to_int(const uint8_t *u24)
	{
	return ((uint32_t)u24[0] \|
	(uint32_t)u24[1] << 8 \|
	(uint32_t)u24[2] << 16);
	}

	static ssize_t read_u16(struct bt_conn conn, const struct bt_gatt_attr attr,
	void *buf, uint16_t len, uint16_t offset)
	{
	const uint16_t *u16 = attr->user_data;
	uint16_t value = sys_cpu_to_le16(*u16);

	return bt_gatt_attr_read(conn, attr, buf, len, offset, &value,
	sizeof(value));
	}

	/* Environmental Sensing Service Declaration */

	struct es_measurement {
	uint16_t flags; /* Reserved for Future Use */
	uint8_t sampling_func;
	uint32_t meas_period;
	uint32_t update_interval;
	uint8_t application;
	uint8_t meas_uncertainty;
	};

	struct temperature_sensor {
	int16_t temp_value;

	/* Valid Range */
	int16_t lower_limit;
	int16_t upper_limit;

	/* ES trigger setting - Value Notification condition */
	uint8_t condition;
	union {
	uint32_t seconds;
	int16_t ref_val; /* Reference temperature */
	};

	struct bt_gatt_ccc_cfg ccc_cfg[CONFIG_BLUETOOTH_MAX_PAIRED];
	struct es_measurement meas;
	};

	struct humidity_sensor {
	int16_t humid_value;

	struct es_measurement meas;
	};

	static bool simulate_temp;
	static struct temperature_sensor sensor_1 = {
	.temp_value = 1200,
	.lower_limit = -10000,
	.upper_limit = 10000,
	.condition = ESS_VALUE_CHANGED,
	.meas.sampling_func = 0x00,
	.meas.meas_period = 0x01,
	.meas.update_interval = SENSOR_1_UPDATE_IVAL,
	.meas.application = 0x1c,
	.meas.meas_uncertainty = 0x04,
	};

	static struct temperature_sensor sensor_2 = {
	.temp_value = 1800,
	.lower_limit = -1000,
	.upper_limit = 5000,
	.condition = ESS_VALUE_CHANGED,
	.meas.sampling_func = 0x00,
	.meas.meas_period = 0x01,
	.meas.update_interval = SENSOR_2_UPDATE_IVAL,
	.meas.application = 0x1b,
	.meas.meas_uncertainty = 0x04,
	};

	static struct humidity_sensor sensor_3 = {
	.humid_value = 6233,
	.meas.sampling_func = 0x02,
	.meas.meas_period = 0x0e10,
	.meas.update_interval = SENSOR_3_UPDATE_IVAL,
	.meas.application = 0x1c,
	.meas.meas_uncertainty = 0x01,
	};

	static void temp_ccc_cfg_changed(const struct bt_gatt_attr *attr,
	uint16_t value)
	{
	simulate_temp = value == BT_GATT_CCC_NOTIFY;
	}

	struct read_es_measurement_rp {
	uint16_t flags; /* Reserved for Future Use */
	uint8_t sampling_function;
	uint8_t measurement_period[3];
	uint8_t update_interval[3];
	uint8_t application;
	uint8_t measurement_uncertainty;
	} __packed;

	static ssize_t read_es_measurement(struct bt_conn *conn,
	const struct bt_gatt_attr attr, void buf,
	uint16_t len, uint16_t offset)
	{
	const struct es_measurement *value = attr->user_data;
	struct read_es_measurement_rp rsp;

	rsp.flags = sys_cpu_to_le16(value->flags);
	rsp.sampling_function = value->sampling_func;
	int_to_le24(value->meas_period, rsp.measurement_period);
	int_to_le24(value->update_interval, rsp.update_interval);
	rsp.application = value->application;
	rsp.measurement_uncertainty = value->meas_uncertainty;

	return bt_gatt_attr_read(conn, attr, buf, len, offset, &rsp,
	sizeof(rsp));
	}

	static ssize_t read_temp_valid_range(struct bt_conn *conn,
	const struct bt_gatt_attr attr, void buf,
	uint16_t len, uint16_t offset)
	{
	const struct temperature_sensor *sensor = attr->user_data;
	uint16_t tmp[] = {sys_cpu_to_le16(sensor->lower_limit),
	sys_cpu_to_le16(sensor->upper_limit)};

	return bt_gatt_attr_read(conn, attr, buf, len, offset, tmp,
	sizeof(tmp));
	}

	struct es_trigger_setting_seconds {
	uint8_t condition;
	uint8_t sec[3];
	} __packed;

	struct es_trigger_setting_reference {
	uint8_t condition;
	int16_t ref_val;
	} __packed;

	static ssize_t read_temp_trigger_setting(struct bt_conn *conn,
	const struct bt_gatt_attr *attr,
	void *buf, uint16_t len,
	uint16_t offset)
	{
	const struct temperature_sensor *sensor = attr->user_data;

	switch (sensor->condition) {
	/* Operand N/A */
	case ESS_TRIGGER_INACTIVE:
	/* fallthrough */
	case ESS_VALUE_CHANGED:
	return bt_gatt_attr_read(conn, attr, buf, len, offset,
	&sensor->condition,
	sizeof(sensor->condition));
	/* Seconds */
	case ESS_FIXED_TIME_INTERVAL:
	/* fallthrough */
	case ESS_NO_LESS_THAN_SPECIFIED_TIME: {
	struct es_trigger_setting_seconds rp;

	rp.condition = sensor->condition;
	int_to_le24(sensor->seconds, rp.sec);

	return bt_gatt_attr_read(conn, attr, buf, len, offset,
	&rp, sizeof(rp));
	}
	/* Reference temperature */
	default: {
	struct es_trigger_setting_reference rp;

	rp.condition = sensor->condition;
	rp.ref_val = sys_cpu_to_le16(sensor->ref_val);

	return bt_gatt_attr_read(conn, attr, buf, len, offset,
	&rp, sizeof(rp));
	}
	}
	}

	static bool check_condition(uint8_t condition, int16_t old_val, int16_t new_val,
	int16_t ref_val)
	{
	switch (condition) {
	case ESS_TRIGGER_INACTIVE:
	return false;
	case ESS_FIXED_TIME_INTERVAL:
	case ESS_NO_LESS_THAN_SPECIFIED_TIME:
	/* TODO: Check time requirements */
	return false;
	case ESS_VALUE_CHANGED:
	return new_val != old_val;
	case ESS_LESS_THAN_REF_VALUE:
	return new_val < ref_val;
	case ESS_LESS_OR_EQUAL_TO_REF_VALUE:
	return new_val <= ref_val;
	case ESS_GREATER_THAN_REF_VALUE:
	return new_val > ref_val;
	case ESS_GREATER_OR_EQUAL_TO_REF_VALUE:
	return new_val >= ref_val;
	case ESS_EQUAL_TO_REF_VALUE:
	return new_val == ref_val;
	case ESS_NOT_EQUAL_TO_REF_VALUE:
	return new_val != ref_val;
	default:
	return false;
	}
	}

	static void update_temperature(struct bt_conn *conn,
	const struct bt_gatt_attr *chrc, int16_t value,
	struct temperature_sensor *sensor)
	{
	bool notify = check_condition(sensor->condition,
	sensor->temp_value, value,
	sensor->ref_val);

	/* Update temperature value */
	sensor->temp_value = value;

	/* Trigger notification if conditions are met */
	if (notify) {
	value = sys_cpu_to_le16(sensor->temp_value);

	bt_gatt_notify(conn, chrc, &value, sizeof(value));
	}
	}

	static struct bt_gatt_attr ess_attrs[] = {
	BT_GATT_PRIMARY_SERVICE(BT_UUID_ESS),

	/* Temperature Sensor 1 */
	BT_GATT_CHARACTERISTIC(BT_UUID_TEMPERATURE,
	BT_GATT_CHRC_READ \| BT_GATT_CHRC_NOTIFY),
	BT_GATT_DESCRIPTOR(BT_UUID_TEMPERATURE, BT_GATT_PERM_READ,
	read_u16, NULL, &sensor_1.temp_value),
	BT_GATT_DESCRIPTOR(BT_UUID_ES_MEASUREMENT, BT_GATT_PERM_READ,
	read_es_measurement, NULL, &sensor_1.meas),
	BT_GATT_CUD(SENSOR_1_NAME, BT_GATT_PERM_READ),
	BT_GATT_DESCRIPTOR(BT_UUID_VALID_RANGE, BT_GATT_PERM_READ,
	read_temp_valid_range, NULL, &sensor_1),
	BT_GATT_DESCRIPTOR(BT_UUID_ES_TRIGGER_SETTING,
	BT_GATT_PERM_READ, read_temp_trigger_setting,
	NULL, &sensor_1),
	BT_GATT_CCC(sensor_1.ccc_cfg, temp_ccc_cfg_changed),

	/* Temperature Sensor 2 */
	BT_GATT_CHARACTERISTIC(BT_UUID_TEMPERATURE,
	BT_GATT_CHRC_READ \| BT_GATT_CHRC_NOTIFY),
	BT_GATT_DESCRIPTOR(BT_UUID_TEMPERATURE, BT_GATT_PERM_READ,
	read_u16, NULL, &sensor_2.temp_value),
	BT_GATT_DESCRIPTOR(BT_UUID_ES_MEASUREMENT, BT_GATT_PERM_READ,
	read_es_measurement, NULL, &sensor_2.meas),
	BT_GATT_CUD(SENSOR_2_NAME, BT_GATT_PERM_READ),
	BT_GATT_DESCRIPTOR(BT_UUID_VALID_RANGE, BT_GATT_PERM_READ,
	read_temp_valid_range, NULL, &sensor_2),
	BT_GATT_DESCRIPTOR(BT_UUID_ES_TRIGGER_SETTING,
	BT_GATT_PERM_READ, read_temp_trigger_setting,
	NULL, &sensor_2),
	BT_GATT_CCC(sensor_2.ccc_cfg, temp_ccc_cfg_changed),

	/* Humidity Sensor */
	BT_GATT_CHARACTERISTIC(BT_UUID_HUMIDITY, BT_GATT_CHRC_READ),
	BT_GATT_DESCRIPTOR(BT_UUID_HUMIDITY, BT_GATT_PERM_READ,
	read_u16, NULL, &sensor_3.humid_value),
	BT_GATT_CUD(SENSOR_3_NAME, BT_GATT_PERM_READ),
	BT_GATT_DESCRIPTOR(BT_UUID_ES_MEASUREMENT, BT_GATT_PERM_READ,
	read_es_measurement, NULL, &sensor_3.meas),
	};

	static void ess_simulate(void)
	{
	static uint8_t i;
	uint16_t val;

	if (!(i % SENSOR_1_UPDATE_IVAL)) {
	val = 1200 + i;
	update_temperature(NULL, &ess_attrs[2], val, &sensor_1);
	}

	if (!(i % SENSOR_2_UPDATE_IVAL)) {
	val = 1800 + i;
	update_temperature(NULL, &ess_attrs[9], val, &sensor_2);
	}

	if (!(i % SENSOR_3_UPDATE_IVAL)) {
	sensor_3.humid_value = 6233 + (i % 13);
	}

	if (!(i % INT8_MAX)) {
	i = 0;
	}

	i++;
	}

	static const struct bt_data ad[] = {
	BT_DATA_BYTES(BT_DATA_FLAGS, (BT_LE_AD_GENERAL \| BT_LE_AD_NO_BREDR)),
	BT_DATA_BYTES(BT_DATA_GAP_APPEARANCE, 0x00, 0x03),
	BT_DATA_BYTES(BT_DATA_UUID16_ALL, 0x1a, 0x18),
	/* TODO: Include Service Data AD */
	};

	static struct bt_data sd[] = {
	BT_DATA(BT_DATA_NAME_COMPLETE, DEVICE_NAME, DEVICE_NAME_LEN),
	};

	static void connected(struct bt_conn *conn, uint8_t err)
	{
	if (err) {
	printk("Connection failed (err %u)\n", err);
	} else {
	printk("Connected\n");
	}
	}

	static void disconnected(struct bt_conn *conn, uint8_t reason)
	{
	printk("Disconnected (reason %u)\n", reason);
	}

	static struct bt_conn_cb conn_callbacks = {
	.connected = connected,
	.disconnected = disconnected,
	};

	static void bt_ready(int err)
	{
	if (err) {
	printk("Bluetooth init failed (err %d)\n", err);
	return;
	}

	printk("Bluetooth initialized\n");

	gap_init(DEVICE_NAME, APPEARANCE_THERMOMETER);
	bt_gatt_register(ess_attrs, ARRAY_SIZE(ess_attrs));
	bas_init();
	dis_init(CONFIG_SOC, "ACME");

	err = bt_le_adv_start(BT_LE_ADV_CONN, ad, ARRAY_SIZE(ad),
	sd, ARRAY_SIZE(sd));
	if (err) {
	printk("Advertising failed to start (err %d)\n", err);
	return;
	}

	printk("Advertising successfully started\n");
	}

	static void auth_passkey_display(struct bt_conn *conn, unsigned int passkey)
	{
	char addr[BT_ADDR_LE_STR_LEN];

	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));

	printk("Passkey for %s: %u\n", addr, passkey);
	}

	static void auth_cancel(struct bt_conn *conn)
	{
	char addr[BT_ADDR_LE_STR_LEN];

	bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));

	printk("Pairing cancelled: %s\n", addr);
	}

	static struct bt_conn_auth_cb auth_cb_display = {
	.passkey_display = auth_passkey_display,
	.passkey_entry = NULL,
	.cancel = auth_cancel,
	};

	void main(void)
	{
	int err;

	err = bt_enable(bt_ready);
	if (err) {
	printk("Bluetooth init failed (err %d)\n", err);
	return;
	}

	bt_conn_cb_register(&conn_callbacks);
	bt_conn_auth_cb_register(&auth_cb_display);

	while (1) {
	k_sleep(MSEC_PER_SEC);

	/* Temperature simulation */
	if (simulate_temp) {
	ess_simulate();
	}

	/* Battery level simulation */
	bas_notify();
	}
	}