How to enable multiple BLE notification and indicate in central side

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I am able to subscribe for differen

Fullscreen 222632.main.c Download

#if 1
/* main.c - Application main entry point */

/*
 * Copyright (c) 2020 SixOctets Systems
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <stdio.h>
#include <stddef.h>
#include <errno.h>

#include <zephyr/zephyr.h>
#include <zephyr/sys/printk.h>
#include <zephyr/sys/byteorder.h>

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


static int scan_start(void);
static uint16_t CTS_read_handle =0xFFU;
static uint16_t fever_read_handle =0xFFU;
#define BT_TEMPERATURE_ADDR_LE_ANY ((bt_addr_le_t[]) { {BT_ADDR_LE_RANDOM, { { 0xEE, 0x4D, 0xAE, 0x55, 0x38, 0xE4 } } } })

//Defining the Temperature alert service UUIDs 
#define BT_UUID_TEMPERATURE_ALERT_SERVICE \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x1b561960, 0xdf3c, 0x4d2a, 0xb319, 0x8f26bee36772))

#define BT_UUID_TEMPERATURE_ALERT_CHARACTER \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x00001961, 0x0000, 0x1000, 0x8000, 0x0805f9b34fb))

#define BT_UUID_TEMPERATURE_ALERT_CCC \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x00002902, 0x0000, 0x1000, 0x8000, 0x00805f9b34fb))

//Defining the Temperature battery service UUIDs 
#define BT_UUID_TEMPERATURE_BATTERY_SERVICE \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x0000180F, 0x0000, 0x1000, 0x8000, 0x00805f9b34fb))

#define BT_UUID_TEMPERATURE_BATTERY_CHARACTER \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x00002A19, 0x0000, 0x1000, 0x8000, 0x00805f9b34fb))

#define BT_UUID_TEMPERATURE_BATTERY_CCC \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x00002902, 0x0000, 0x1000, 0x8000, 0x00805f9b34fb))

//Defining the Temperature Measurement UUIDs 
#define BT_UUID_TEMPERATURE_MEASUREMENT_SERVICE \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x00001809, 0x0000, 0x1000, 0x8000, 0x00805f9b34fb))

#define BT_UUID_TEMPERATURE_MEASUREMENT_CHARACTER \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x00002A1C, 0x0000, 0x1000, 0x8000, 0x00805f9b34fb))

#define BT_UUID_TEMPERATURE_MEASUREMENT_CCC \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x00002902, 0x0000, 0x1000, 0x8000, 0x00805f9b34fb))

//Defining the Temperature MOVEMENT UUIDs 
#define BT_UUID_TEMPERATURE_MOVEMENT_SERVICE \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0xe68f1980, 0x8e6d, 0x4254, 0x9650, 0xa4c165f927c8))

#define BT_UUID_TEMPERATURE_POSITION_CHARACTER \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x00001981, 0x0000, 0x1000, 0x8000, 0x00805f9b34fb))

#define BT_UUID_TEMPERATURE_POSITION_CCC \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x00002902, 0x0000, 0x1000, 0x8000, 0x00805f9b34fb))

//Defining the Temperature Fever and color alert UUIDs 
#define BT_UUID_TEMPERATURE_COLOR_SERVICE \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0xc67b1970, 0x5a63, 0x41d4, 0x9f35, 0xf5218e4c6c83))

#define BT_UUID_TEMPERATURE_FEVER_ALERT_CHARACTER \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x00001972, 0x0000, 0x1000, 0x8000, 0x00805f9b34fb))

struct bt_conn *default_conn;
struct bt_uuid_16 uuid = BT_UUID_INIT_16(0);

struct bt_gatt_discover_params bas_discover_params;
struct bt_gatt_discover_params hts_discover_params;
struct bt_gatt_discover_params alert_discover_params;
struct bt_gatt_discover_params pos_discover_params;
struct bt_gatt_discover_params fev_cts_discover_params;
struct bt_gatt_discover_params cts_discover_params;

struct bt_gatt_subscribe_params bas_subscribe_params;
struct bt_gatt_subscribe_params hts_subscribe_params;
struct bt_gatt_subscribe_params alert_subscribe_params;
struct bt_gatt_subscribe_params pos_subscribe_params;


struct bt_gatt_read_params read_params;
struct bt_gatt_write_params CTS_write;
struct bt_gatt_write_params fever_alert_write;
struct bt_uuid_128 uuid_temp = BT_UUID_INIT_128(0);

static const uint8_t fever_temperature_limit[] = {0x00,0x0F}; //38.4 C max temperature
uint8_t value[10]={0xE6,0x07,0x0C,0x1D, 0x0C,0x01, 0x00,0x01, 0x00,0x00}; 

static uint8_t discover_func_temperature(struct bt_conn *conn,const struct bt_gatt_attr *attr,struct bt_gatt_discover_params *params);
static uint8_t discover_func_position(struct bt_conn *conn,const struct bt_gatt_attr *attr,struct bt_gatt_discover_params *params);
static uint8_t discover_func_alert(struct bt_conn *conn,const struct bt_gatt_attr *attr,struct bt_gatt_discover_params *params);
static uint8_t discover_func_battery(struct bt_conn *conn,const struct bt_gatt_attr *attr,struct bt_gatt_discover_params *params);
static uint8_t discover_func_fev_alert(struct bt_conn *conn,const struct bt_gatt_attr *attr,struct bt_gatt_discover_params *params);
static uint8_t discover_func_CTS(struct bt_conn *conn,const struct bt_gatt_attr *attr,struct bt_gatt_discover_params *params);

static double pow(double x, double y)
{
	double result = 1;

	if (y < 0) {
		y = -y;
		while (y--) {
			result /= x;
		}
	} else {
		while (y--) {
			result *= x;
		}
	}

	return result;
}

static uint8_t notify_func_temp(struct bt_conn *conn,
			   struct bt_gatt_subscribe_params *params,
			   const void *data, uint16_t length)
{
	double temperature;
	uint32_t mantissa;
	int8_t exponent;
	printk("Temperature notify\n");
	// if (!data) {
	// 	printk("[UNSUBSCRIBED]\n");
	// 	params->value_handle = 0U;
	// 	return BT_GATT_ITER_STOP;
	// }
	uint8_t *d = (uint8_t *)data;
	for (int i =0; i < length; i++){
		printk("%2x ", d[i]);
	}
	printk("\n");
	// /* temperature value display */
	// mantissa = sys_get_le24(&((uint8_t *)data)[1]);
	// exponent = ((uint8_t *)data)[4];
	// temperature = (double)mantissa * pow(10, exponent);

	// printf("Temperature %gC.\n", temperature);

	return BT_GATT_ITER_CONTINUE;
}

static uint8_t notify_func_battery(struct bt_conn *conn,
			   struct bt_gatt_subscribe_params *params,
			   const void *data, uint16_t length)
{
	
	printk("Battery notify\n");
	// if (!data) {
	// 	printk("[UNSUBSCRIBED]\n");
	// 	params->value_handle = 0U;
	// 	return BT_GATT_ITER_STOP;
	// }
	uint8_t *d = (uint8_t *)data;
	for (int i =0; i < length; i++){
		printk("%2x ", d[i]);
	}
	printk("\n");
	return BT_GATT_ITER_CONTINUE;
}
static uint8_t notify_func_position(struct bt_conn *conn,
			   struct bt_gatt_subscribe_params *params,
			   const void *data, uint16_t length)
{
	
	printk("Position notify\n");
	// if (!data) {
	// 	printk("[UNSUBSCRIBED]\n");
	// 	params->value_handle = 0U;
	// 	return BT_GATT_ITER_STOP;
	// }
	uint8_t *d = (uint8_t *)data;
	for (int i =0; i < length; i++){
		printk("%2x ", d[i]);
	}
	printk("\n");
	return BT_GATT_ITER_CONTINUE;
}

static uint8_t notify_func_alert(struct bt_conn *conn,
			   struct bt_gatt_subscribe_params *params,
			   const void *data, uint16_t length)
{
	
	printk("Alert notify\n");
	// if (!data) {
	// 	printk("[UNSUBSCRIBED]\n");
	// 	params->value_handle = 0U;
	// 	return BT_GATT_ITER_STOP;
	// }
	uint8_t *d = (uint8_t *)data;
	for (int i =0; i < length; i++){
		printk("%2x ", d[i]);
	}
	printk("\n");
	return BT_GATT_ITER_CONTINUE;
}


static uint8_t read_func_cb(struct bt_conn *conn,
                 uint8_t err, struct bt_gatt_read_params *params,
                 const void *data, uint16_t length)
{
	
    if ((data != NULL) && (err == 0))
    {
        if (params->single.handle== CTS_read_handle)
        {
            uint8_t *d = (uint8_t *)data;
           	printk("length %2x \n",length);
			for (int i =0; i < length; i++){
				printk("%2x ", d[i]);
			}
        }
		printk("\n");
    }else{
		printk("No data\n");
	}

    return BT_GATT_ITER_STOP;
}


static void write_cb(struct bt_conn *conn, uint8_t err, struct bt_gatt_write_params *params)
{
	if (err != BT_ATT_ERR_SUCCESS) {
		printk("Write failed: 0x%02X\n", err);
	}else{
		printk("\nafter Write CTS sucess\n");
	}

	
}

static void write_fever_cb(struct bt_conn *conn, uint8_t err, struct bt_gatt_write_params *params)
{
	if (err != BT_ATT_ERR_SUCCESS) {
		printk("Write failed: 0x%02X\n", err);
	}else{
		printk("Write sucess \n");
	}

	
}

static void security_changed(struct bt_conn *conn, bt_security_t level,
			     enum bt_security_err err)
{
	printk("%s: to level %u (err %u)\n", __func__, level, err);
}
static uint8_t discover_func_temperature(struct bt_conn *conn,
			     const struct bt_gatt_attr *attr,
			     struct bt_gatt_discover_params *params)
{
	int err;

	if (!attr) {
		printk("Discover complete\n");
		(void)memset(params, 0, sizeof(*params));
		return BT_GATT_ITER_STOP;
	}

	printk("temperature [ATTRIBUTE] handle %u\n", attr->handle);

	if (!bt_uuid_cmp(hts_discover_params.uuid, BT_UUID_HTS)) {
		memcpy(&uuid, BT_UUID_HTS_MEASUREMENT, sizeof(uuid));
		hts_discover_params.uuid = &uuid.uuid;
		hts_discover_params.start_handle = attr->handle + 1;
		hts_discover_params.type = BT_GATT_DISCOVER_CHARACTERISTIC;

		err = bt_gatt_discover(conn, &hts_discover_params);
		if (err) {
			printk("Discover failed 1(err %d)\n", err);
		}
	} else if (!bt_uuid_cmp(hts_discover_params.uuid,BT_UUID_HTS_MEASUREMENT)) 
	{
		memcpy(&uuid, BT_UUID_GATT_CCC, sizeof(uuid));
		hts_discover_params.uuid = &uuid.uuid;
		hts_discover_params.start_handle = attr->handle + 2;
		hts_discover_params.type = BT_GATT_DISCOVER_DESCRIPTOR;
		hts_subscribe_params.value_handle = bt_gatt_attr_value_handle(attr);

		err = bt_gatt_discover(conn, &hts_discover_params);
		if (err) {
			printk("Discover failed 2(err %d)\n", err);
		}
	} else {
		hts_subscribe_params.notify = notify_func_temp;
		hts_subscribe_params.value = BT_GATT_CCC_INDICATE;
		hts_subscribe_params.min_security = bt_conn_get_security(conn);
		hts_subscribe_params.ccc_handle = attr->handle ;

		err = bt_gatt_subscribe(conn, &hts_subscribe_params);
		if (err && err != -EALREADY) {
			printk("Subscribe failed (err %d)\n", err);
		} else {
			printk("temperature measurement [SUBSCRIBED]\n");
		}

		memcpy(&uuid_temp, BT_UUID_TEMPERATURE_MOVEMENT_SERVICE, sizeof(uuid_temp));
		pos_discover_params.uuid = &uuid_temp.uuid;
		pos_discover_params.func = discover_func_position;
		pos_discover_params.start_handle = BT_ATT_FIRST_ATTRIBUTE_HANDLE;
		pos_discover_params.end_handle = BT_ATT_LAST_ATTRIBUTE_HANDLE;
		pos_discover_params.type = BT_GATT_DISCOVER_PRIMARY;

		err = bt_gatt_discover(default_conn, &pos_discover_params);
		if (err) {
			printk("Discover failed(err %d)\n", err);
			return;
		}

		return BT_GATT_ITER_STOP;
	}

	return BT_GATT_ITER_STOP;
}



static uint8_t discover_func_battery(struct bt_conn *conn,
			     const struct bt_gatt_attr *attr,
			     struct bt_gatt_discover_params *params)
{
	int err;
	if (!attr) {
		printk("Discover complete\n");
		(void)memset(params, 0, sizeof(*params));
		return BT_GATT_ITER_STOP;
	}
	
	printk("Battery [ATTRIBUTE] handle %u\n", attr->handle);

	if (!bt_uuid_cmp(bas_discover_params.uuid, BT_UUID_TEMPERATURE_BATTERY_SERVICE)) {
		memcpy(&uuid_temp, BT_UUID_TEMPERATURE_BATTERY_CHARACTER, sizeof(uuid_temp));
		bas_discover_params.uuid = &uuid_temp.uuid;
		bas_discover_params.start_handle = attr->handle + 1;
		bas_discover_params.type = BT_GATT_DISCOVER_CHARACTERISTIC;

		
		err = bt_gatt_discover(conn, &bas_discover_params);
		if (err) {
			printk("Discover failed 3 (err %d)\n", err);
		}
	} else if (!bt_uuid_cmp(bas_discover_params.uuid,
				BT_UUID_TEMPERATURE_BATTERY_CHARACTER)) {
		memcpy(&uuid_temp, BT_UUID_GATT_CCC, sizeof(uuid_temp));
		bas_discover_params.uuid = &uuid_temp.uuid;
		bas_discover_params.start_handle = attr->handle + 2;
		bas_discover_params.type = BT_GATT_DISCOVER_DESCRIPTOR;
		bas_subscribe_params.value_handle = bt_gatt_attr_value_handle(attr);
	
		err = bt_gatt_discover(conn, &bas_discover_params);
		if (err) {
			printk("Discover failed 4(err %d)\n", err);
		}
		
	} 
	else {
		bas_subscribe_params.notify= notify_func_battery;
		bas_subscribe_params.value = BT_GATT_CCC_NOTIFY;
		bas_subscribe_params.min_security = bt_conn_get_security(conn);
		bas_subscribe_params.ccc_handle = attr->handle;

		err = bt_gatt_subscribe(conn, &bas_subscribe_params);
		if (err && err != -EALREADY) {
			printk("Subscribe failed (err %d)\n", err);
		} else {
			printk("Battery characteristics [SUBSCRIBED]\n");
			
		}

		return BT_GATT_ITER_STOP;
	}

	return BT_GATT_ITER_STOP;
}

static uint8_t discover_func_alert(struct bt_conn *conn,
			     const struct bt_gatt_attr *attr,
			     struct bt_gatt_discover_params *params)
{
	int err;
	if(!attr)
	{
		printk("Discover complete\n");
		(void)memset(params, 0, sizeof(*params));
		return BT_GATT_ITER_STOP;
	}

	printk("alert [ATTRIBUTE] handle %u\n", attr->handle);

	if (!bt_uuid_cmp(alert_discover_params.uuid, BT_UUID_TEMPERATURE_ALERT_SERVICE))
	{
		memcpy(&uuid_temp, BT_UUID_TEMPERATURE_ALERT_CHARACTER, sizeof(uuid_temp));
		alert_discover_params.uuid = &uuid_temp.uuid;
		alert_discover_params.start_handle = attr->handle + 1;
		alert_discover_params.type = BT_GATT_DISCOVER_CHARACTERISTIC;

		err = bt_gatt_discover(conn, &alert_discover_params);
		if (err)
		{
			printk("Discover failed 5 (err %d)\n", err);
		}
	}
	else if (!bt_uuid_cmp(alert_discover_params.uuid, BT_UUID_TEMPERATURE_ALERT_CHARACTER))
	{
		memcpy(&uuid_temp, BT_UUID_TEMPERATURE_ALERT_CCC, sizeof(uuid_temp));
		alert_discover_params.uuid = &uuid_temp.uuid;
		alert_discover_params.start_handle = attr->handle + 2;
		alert_discover_params.type = BT_GATT_DISCOVER_DESCRIPTOR;
		alert_subscribe_params.value_handle = bt_gatt_attr_value_handle(attr);

		err = bt_gatt_discover(conn, &alert_discover_params);
		if (err)
		{
			printk("Discover failed 6(err %d)\n", err);
		}
	} else {
		alert_subscribe_params.notify = notify_func_alert;
		alert_subscribe_params.value = BT_GATT_CCC_INDICATE;
		alert_subscribe_params.min_security = bt_conn_get_security(conn);
		alert_subscribe_params.ccc_handle = attr->handle;

		err = bt_gatt_subscribe(conn, &alert_subscribe_params);
		if (err && err != -EALREADY) {
			printk("Subscribe failed (err %d)\n", err);
		} else {
			printk("Alert characteristics [SUBSCRIBED]\n");
		}

		memcpy(&uuid_temp, BT_UUID_TEMPERATURE_COLOR_SERVICE, sizeof(uuid_temp));
		fev_cts_discover_params.uuid = &uuid_temp.uuid;
		fev_cts_discover_params.func = discover_func_fev_alert;
		fev_cts_discover_params.start_handle = BT_ATT_FIRST_ATTRIBUTE_HANDLE;
		fev_cts_discover_params.end_handle = BT_ATT_LAST_ATTRIBUTE_HANDLE;
		fev_cts_discover_params.type = BT_GATT_DISCOVER_PRIMARY;

		err = bt_gatt_discover(default_conn, &fev_cts_discover_params);
		if (err) {
			printk("Discover failed(err %d)\n", err);
			return;
		}
		return BT_GATT_ITER_STOP;
	}

	return BT_GATT_ITER_STOP;
}

static uint8_t discover_func_position(struct bt_conn *conn,
			     const struct bt_gatt_attr *attr,
			     struct bt_gatt_discover_params *params)
{
	int err;

	if (!attr)
	{
		printk("Discover complete\n");
		(void)memset(params, 0, sizeof(*params));
		return BT_GATT_ITER_STOP;
	}

	printk("position [ATTRIBUTE] handle %u\n", attr->handle);

	if (!bt_uuid_cmp(pos_discover_params.uuid, BT_UUID_TEMPERATURE_MOVEMENT_SERVICE))
	{
		memcpy(&uuid_temp, BT_UUID_TEMPERATURE_POSITION_CHARACTER, sizeof(uuid_temp));
		pos_discover_params.uuid = &uuid_temp.uuid;
		pos_discover_params.start_handle = attr->handle + 1;
		pos_discover_params.type = BT_GATT_DISCOVER_CHARACTERISTIC;

		err = bt_gatt_discover(conn, &pos_discover_params);
		if (err)
		{
			printk("Discover failed 7(err %d)\n", err);
		}
	}
	else if (!bt_uuid_cmp(pos_discover_params.uuid, BT_UUID_TEMPERATURE_POSITION_CHARACTER))
	{
		memcpy(&uuid_temp, BT_UUID_TEMPERATURE_POSITION_CCC, sizeof(uuid_temp));
		pos_discover_params.uuid = &uuid_temp.uuid;
		pos_discover_params.start_handle = attr->handle + 2;
		pos_discover_params.type = BT_GATT_DISCOVER_DESCRIPTOR;
		pos_subscribe_params.value_handle = bt_gatt_attr_value_handle(attr);

		err = bt_gatt_discover(conn, &pos_discover_params);
		if (err)
		{
			printk("Discover failed 8(err %d)\n", err);
		}
	} else {
		pos_subscribe_params.notify = notify_func_position;
		pos_subscribe_params.value = BT_GATT_CCC_INDICATE;
		pos_subscribe_params.min_security = bt_conn_get_security(conn);
		pos_subscribe_params.ccc_handle = attr->handle;
	
		err = bt_gatt_subscribe(conn, &pos_subscribe_params);
		if (err && err != -EALREADY) {
			printk("Subscribe failed (err %d)\n", err);
		} else {
			printk("position characteristics [SUBSCRIBED]\n");
		}

		memcpy(&uuid_temp, BT_UUID_TEMPERATURE_ALERT_SERVICE, sizeof(uuid_temp));
		alert_discover_params.uuid = &uuid_temp.uuid;
		alert_discover_params.func = discover_func_alert;
		alert_discover_params.start_handle = BT_ATT_FIRST_ATTRIBUTE_HANDLE;
		alert_discover_params.end_handle = BT_ATT_LAST_ATTRIBUTE_HANDLE;
		alert_discover_params.type = BT_GATT_DISCOVER_PRIMARY;

		err = bt_gatt_discover(default_conn, &alert_discover_params);
		if (err) {
			printk("Discover failed(err %d)\n", err);
	
		}
		return BT_GATT_ITER_STOP;
	}
	return BT_GATT_ITER_STOP;
}


static uint8_t discover_func_fev_alert(struct bt_conn *conn,
			     const struct bt_gatt_attr *attr,
			     struct bt_gatt_discover_params *params)
{
	int err;
	if (!attr)
	{
		printk("Discover complete\n");
		(void)memset(params, 0, sizeof(*params));
		return BT_GATT_ITER_STOP;
	}

	printk("fev alert [ATTRIBUTE] handle %u\n", attr->handle);

	if (!bt_uuid_cmp(fev_cts_discover_params.uuid, BT_UUID_TEMPERATURE_COLOR_SERVICE))
	{
		memcpy(&uuid_temp, BT_UUID_TEMPERATURE_FEVER_ALERT_CHARACTER, sizeof(uuid_temp));
		fev_cts_discover_params.uuid = &uuid_temp.uuid;
		fev_cts_discover_params.start_handle = attr->handle + 1;
		fev_cts_discover_params.type = BT_GATT_DISCOVER_CHARACTERISTIC;
		
		err = bt_gatt_discover(conn, &fev_cts_discover_params);
		if (err)
		{
			printk("Discover failed 9(err %d)\n", err);
		}
	}

	else if (!bt_uuid_cmp(fev_cts_discover_params.uuid, BT_UUID_TEMPERATURE_FEVER_ALERT_CHARACTER))
	{
	
		fever_alert_write.handle =  bt_gatt_attr_value_handle(attr);;
		fever_alert_write.func = write_fever_cb;
		fever_alert_write.offset = 0;
		fever_alert_write.data = fever_temperature_limit;
		fever_alert_write.length = sizeof(fever_temperature_limit);

		// UNSET_FLAG(flag_write_complete);
		printk("bt write start \n");
		err = bt_gatt_write(conn, &fever_alert_write);
		if(err){
			printk("write failed (err %d)\n", err);
			return BT_GATT_ITER_STOP;
		}

		memcpy(&uuid, BT_UUID_CTS, sizeof(uuid));
		fev_cts_discover_params.uuid = &uuid.uuid;
		fev_cts_discover_params.start_handle = attr->handle + 2;
		fev_cts_discover_params.type = BT_GATT_DISCOVER_PRIMARY;

		err = bt_gatt_discover(default_conn, &fev_cts_discover_params);
		if (err) {
			printk("Discover failed(err %d)\n", err);
			
		}

		memcpy(&uuid, BT_UUID_CTS, sizeof(uuid));
		cts_discover_params.uuid = &uuid.uuid;
		cts_discover_params.func = discover_func_CTS;
		cts_discover_params.start_handle = BT_ATT_FIRST_ATTRIBUTE_HANDLE;
		cts_discover_params.end_handle = BT_ATT_LAST_ATTRIBUTE_HANDLE;
		cts_discover_params.type = BT_GATT_DISCOVER_PRIMARY;

		err = bt_gatt_discover(default_conn, &cts_discover_params);
		if (err) {
			printk("Discover failed(err %d)\n", err);
		
		}

	}
	
	return BT_GATT_ITER_STOP;
}


static uint8_t discover_func_CTS(struct bt_conn *conn,
			     const struct bt_gatt_attr *attr,
			     struct bt_gatt_discover_params *params)
{
	int err;
	if (!attr)
	{
		printk("Discover complete\n");
		(void)memset(params, 0, sizeof(*params));
		return BT_GATT_ITER_STOP;
	}

	printk("CTS [ATTRIBUTE] handle %u\n", attr->handle);

	if (!bt_uuid_cmp(cts_discover_params.uuid, BT_UUID_CTS))
	{
		memcpy(&uuid, BT_UUID_CTS_CURRENT_TIME, sizeof(uuid));
		cts_discover_params.uuid = &uuid.uuid;
		cts_discover_params.start_handle = attr->handle + 1;
		cts_discover_params.type = BT_GATT_DISCOVER_CHARACTERISTIC;
		
		err = bt_gatt_discover(conn, &cts_discover_params);
		if (err)
		{
			printk("Discover failed 10(err %d)\n", err);
		}
	}
	else if (!bt_uuid_cmp(cts_discover_params.uuid, BT_UUID_CTS_CURRENT_TIME))
	{
		/* Current time characteristic discovered */
        CTS_read_handle = bt_gatt_attr_value_handle(attr);
		printk("before write CTS \n");
        /* Read Tx Power */
        read_params.func = read_func_cb;
        read_params.handle_count = 1;
        read_params.single.handle = CTS_read_handle;
        read_params.single.offset = 0;

        err = bt_gatt_read(conn, &read_params);
        if (err)
        {
            printk("GATT Read failed (err %d)\n", err);
        }

		CTS_read_handle =bt_gatt_attr_value_handle(attr);
		CTS_write.handle =  CTS_read_handle;
		CTS_write.func = write_cb;
		CTS_write.offset = 0;
		CTS_write.data = value;
		CTS_write.length = sizeof(value);
		

		err = bt_gatt_write(conn, &CTS_write);
		if(err){
			printk("write failed (err %d)\n", err);
			return BT_GATT_ITER_STOP;
		}
	

		/* Current time characteristic discovered */
        CTS_read_handle = bt_gatt_attr_value_handle(attr);

        /* Read Tx Power */
        read_params.func = read_func_cb;
        read_params.handle_count = 1;
        read_params.single.handle = CTS_read_handle;
        read_params.single.offset = 0;

        err = bt_gatt_read(conn, &read_params);
        if (err)
        {
            printk("GATT Read failed (err %d)\n", err);
        }


	} 

	return BT_GATT_ITER_STOP;

}

static void connected(struct bt_conn *conn, uint8_t conn_err)
{
	char addr[BT_ADDR_LE_STR_LEN];
	int err;

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

	if (conn_err) {
		printk("Failed to connect to %s (%u)\n", addr, conn_err);

		bt_conn_unref(default_conn);
		default_conn = NULL;

		scan_start();
		return;
	}

	printk("Connected: %s\n", addr);

	err = bt_conn_set_security(conn, BT_SECURITY_L2);
	if (err) {
		printk("bt_conn_set_security failed (err %d)\n", err);
		return;
	}

	if (conn == default_conn) {
		
		
		memcpy(&uuid_temp, BT_UUID_TEMPERATURE_BATTERY_SERVICE, sizeof(uuid_temp));
		bas_discover_params.uuid = &uuid_temp.uuid;
		bas_discover_params.func = discover_func_battery;
		bas_discover_params.start_handle = BT_ATT_FIRST_ATTRIBUTE_HANDLE;
		bas_discover_params.end_handle = BT_ATT_LAST_ATTRIBUTE_HANDLE;
		bas_discover_params.type = BT_GATT_DISCOVER_PRIMARY;

		err = bt_gatt_discover(default_conn, &bas_discover_params);
		if (err) {
			printk("Discover failed(err %d)\n", err);
			//return BT_GATT_ITER_STOP;
		}
		
		memcpy(&uuid_temp, BT_UUID_TEMPERATURE_MEASUREMENT_SERVICE, sizeof(uuid_temp));
		hts_discover_params.uuid = &uuid_temp.uuid;
		hts_discover_params.func = discover_func_temperature;
		hts_discover_params.start_handle = BT_ATT_FIRST_ATTRIBUTE_HANDLE;
		hts_discover_params.end_handle = BT_ATT_LAST_ATTRIBUTE_HANDLE;
		hts_discover_params.type = BT_GATT_DISCOVER_PRIMARY;

		err = bt_gatt_discover(default_conn, &hts_discover_params);
		if (err) {
			printk("Discover failed(err %d)\n", err);
			
		}
		
	}
	
}

static bool eir_found(struct bt_data *data, void *user_data)
{
	bt_addr_le_t *addr = user_data;
	int i;

	printk("[AD]: %u data_len %u\n", data->type, data->data_len);

	switch (data->type) {
	case BT_DATA_UUID16_SOME:
	case BT_DATA_UUID16_ALL:
		if (data->data_len % sizeof(uint16_t) != 0U) {
			printk("AD malformed\n");
			return true;
		}

		for (i = 0; i < data->data_len; i += sizeof(uint16_t)) {
			struct bt_uuid *uuid;
			uint16_t u16;
			int err;

			memcpy(&u16, &data->data[i], sizeof(u16));
			
			uuid = BT_UUID_DECLARE_16(sys_le16_to_cpu(u16));
			
			if (bt_uuid_cmp(uuid, BT_UUID_HTS)) {
				printk("HTS UUID matched \n");
				continue;
			}

			err = bt_le_scan_stop();
			if (err) {
				printk("Stop LE scan failed (err %d)\n", err);
				continue;
			}

			err = bt_conn_le_create(addr, BT_CONN_LE_CREATE_CONN,
						BT_LE_CONN_PARAM_DEFAULT,
						&default_conn);
			if (err) {
				printk("Create connection failed (err %d)\n",
				       err);
				scan_start();
			}

			return false;
		}
	}

	return true;
}

static void device_found(const bt_addr_le_t *addr, int8_t rssi, uint8_t type,
			 struct net_buf_simple *ad)
{
	char dev[BT_ADDR_LE_STR_LEN];

	

	if(bt_addr_cmp(BT_TEMPERATURE_ADDR_LE_ANY, addr) == 0){
			
		bt_addr_le_to_str(addr, dev, sizeof(dev));
		printk("[DEVICE]: %s, AD evt type %u, AD data len %u, RSSI %i\n",
	       dev, type, ad->len, rssi);

		/* We're only interested in connectable events */
		if (type == BT_HCI_ADV_IND || type == BT_HCI_ADV_DIRECT_IND) {
			bt_data_parse(ad, eir_found, (void *)addr);
		}
	}
}

static int scan_start(void)
{
	/* Use active scanning and disable duplicate filtering to handle any
	 * devices that might update their advertising data at runtime.
	 */
	struct bt_le_scan_param scan_param = {
		.type       = BT_LE_SCAN_TYPE_ACTIVE,
		.options    = BT_LE_SCAN_OPT_NONE,
		.interval   = BT_GAP_SCAN_FAST_INTERVAL,
		.window     = BT_GAP_SCAN_FAST_WINDOW,
	};

	return bt_le_scan_start(&scan_param, device_found);
}


static void disconnected(struct bt_conn *conn, uint8_t reason)
{
	char addr[BT_ADDR_LE_STR_LEN];
	int err;

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

	printk("Disconnected: %s (reason 0x%02x)\n", addr, reason);

	if (default_conn != conn) {
		return;
	}

	bt_conn_unref(default_conn);
	default_conn = NULL;

	err = scan_start();
	if (err) {
		printk("Scanning failed to start (err %d)\n", err);
	}
}

BT_CONN_CB_DEFINE(conn_callbacks) = {
	.connected = connected,
	.disconnected = disconnected,
	.security_changed =security_changed,
};

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

	printk("Bluetooth initialized\n");

	err = scan_start();

	if (err) {
		printk("Scanning failed to start (err %d)\n", err);
		return;
	}

	printk("Scanning successfully started\n");
}
#else
/* main.c - Application main entry point */

/*
 * Copyright (c) 2015-2016 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <zephyr/types.h>
#include <stddef.h>
#include <errno.h>
#include <zephyr/kernel.h>
#include <zephyr/sys/printk.h>

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

static void start_scan(void);
#define NAME_LEN 30

#define SPO2_NAME (char[9]){"BerryMed"}

#define BT_TEMPERATURE_ADDR_LE_ANY ((bt_addr_le_t[]) { { BT_ADDR_LE_RANDOM, { { 0xEE, 0x4D, 0xAE, 0x55, 0x38, 0xE4 } } } })
//Defining the different UUIDs for the Services of Wireless Temperature "tucky"

//Defining the Temperature alert service UUIDs 
#define BT_UUID_TEMPERATURE_ALERT_SERVICE \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x1b561960, 0xdf3c, 0x4d2a, 0xb319, 0x8f26bee36772))

#define BT_UUID_TEMPERATURE_ALERT_CHARACTER \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x00001961, 0x0000, 0x1000, 0x8000, 0x0805f9b34fb))

#define BT_UUID_TEMPERATURE_ALERT_CCC \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x00002902, 0x0000, 0x1000, 0x8000, 0x00805f9b34fb))


//Defining the Temperature battery service UUIDs 
#define BT_UUID_TEMPERATURE_BATTERY_SERVICE \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x0000180F, 0x0000, 0x1000, 0x8000, 0x00805f9b34fb))

#define BT_UUID_TEMPERATURE_BATTERY_CHARACTER \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x00002A19, 0x0000, 0x1000, 0x8000, 0x00805f9b34fb))

#define BT_UUID_TEMPERATURE_BATTERY_CCC \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x00002902, 0x0000, 0x1000, 0x8000, 0x00805f9b34fb))

//Defining the Temperature Measurement UUIDs 
#define BT_UUID_TEMPERATURE_MEASUREMENT_SERVICE \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x00001809, 0x0000, 0x1000, 0x8000, 0x00805f9b34fb))

#define BT_UUID_TEMPERATURE_MEASUREMENT_CHARACTER \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x00002A1C, 0x0000, 0x1000, 0x8000, 0x00805f9b34fb))

#define BT_UUID_TEMPERATURE_MEASUREMENT_CCC \
	BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x00002902, 0x0000, 0x1000, 0x8000, 0x00805f9b34fb))


static struct bt_conn *default_conn;

static struct bt_uuid_128 uuid = BT_UUID_INIT_128(0);
static struct bt_gatt_discover_params discover_params;
static struct bt_gatt_subscribe_params subscribe_params;


static uint8_t notify_func(struct bt_conn *conn,
			   struct bt_gatt_subscribe_params *params,
			   const void *data, uint16_t length)
{
	printk("Temperature notify\n");
	// if (!data) {
	// 	printk("[UNSUBSCRIBED]\n");
	// 	params->value_handle = 0U;
	// 	return BT_GATT_ITER_STOP;
	// }
	uint8_t *d = (uint8_t *)data;
	for (int i =0; i < length; i++){
		printk("%2x ", d[i]);
	}
	printk("\n");

	return BT_GATT_ITER_CONTINUE;
}
static uint8_t discover_func(struct bt_conn *conn,
			     const struct bt_gatt_attr *attr,
			     struct bt_gatt_discover_params *params){
	int err;

	printk("Discovering...\n");

	printk("attr: %u\n", (unsigned int)attr);

	if (!attr)
	{
		printk("Discover complete\n");
		(void)memset(params, 0, sizeof(*params));
		return BT_GATT_ITER_STOP;
	}

	printk("[ATTRIBUTE] handle %u\n", attr->handle);

	if (!bt_uuid_cmp(discover_params.uuid, BT_UUID_TEMPERATURE_ALERT_SERVICE))
	{
		memcpy(&uuid, BT_UUID_TEMPERATURE_ALERT_CHARACTER, sizeof(uuid));
		discover_params.uuid = &uuid.uuid;
		discover_params.start_handle = attr->handle + 1;
		discover_params.type = BT_GATT_DISCOVER_CHARACTERISTIC;

		err = bt_gatt_discover(conn, &discover_params);
		if (err)
		{
			printk("Discover failed (err %d)\n", err);
		}
	}
	else if (!bt_uuid_cmp(discover_params.uuid, BT_UUID_TEMPERATURE_ALERT_CHARACTER))
	{
		memcpy(&uuid, BT_UUID_TEMPERATURE_ALERT_CCC, sizeof(uuid));
		discover_params.uuid = &uuid.uuid;
		discover_params.start_handle = attr->handle + 2;
		discover_params.type = BT_GATT_DISCOVER_DESCRIPTOR;
		subscribe_params.value_handle = bt_gatt_attr_value_handle(attr);

		err = bt_gatt_discover(conn, &discover_params);
		if (err)
		{
			printk("Discover failed (err %d)\n", err);
		}
	}
	else
	{
		subscribe_params.notify = notify_func;
		subscribe_params.value = BT_GATT_CCC_INDICATE;
		subscribe_params.ccc_handle = attr->handle;

		err = bt_gatt_subscribe(conn, &subscribe_params);
		if (err && err != -EALREADY)
		{
			printk("Subscribe failed (err %d)\n", err);
		}
		else
		{
			printk("[SUBSCRIBED]\n");
			//ble_spo2_conn_sucess = true;
			//blow_buzzer();
			//k_msleep(500);
		}

		return BT_GATT_ITER_STOP;
	}

	return BT_GATT_ITER_STOP;
}
static uint8_t discover_func_HTS(struct bt_conn *conn,
			     const struct bt_gatt_attr *attr,
			     struct bt_gatt_discover_params *params)
{
	int err;
	
	printk("Discovering...\n");

	if (!attr)
	{
		printk("Discover complete\n");
		(void)memset(params, 0, sizeof(*params));
		return BT_GATT_ITER_CONTINUE;
	}

	printk("[ATTRIBUTE] handle %u\n", attr->handle);

	if (!bt_uuid_cmp(discover_params.uuid, BT_UUID_TEMPERATURE_MEASUREMENT_SERVICE))
	{
		memcpy(&uuid, BT_UUID_TEMPERATURE_MEASUREMENT_CHARACTER, sizeof(uuid));
		discover_params.uuid = &uuid.uuid;
		discover_params.start_handle = attr->handle + 1;
		discover_params.type = BT_GATT_DISCOVER_CHARACTERISTIC;

		err = bt_gatt_discover(conn, &discover_params);
		if (err)
		{
			printk("Discover failed (err %d)\n", err);
		}
	}
	else if (!bt_uuid_cmp(discover_params.uuid, BT_UUID_TEMPERATURE_MEASUREMENT_CHARACTER))
	{
		memcpy(&uuid, BT_UUID_TEMPERATURE_MEASUREMENT_CCC, sizeof(uuid));
		discover_params.uuid = &uuid.uuid;
		discover_params.start_handle = attr->handle + 2;
		discover_params.type = BT_GATT_DISCOVER_DESCRIPTOR;
		subscribe_params.value_handle = bt_gatt_attr_value_handle(attr);

		err = bt_gatt_discover(conn, &discover_params);
		if (err)
		{
			printk("Discover failed (err %d)\n", err);
		}
	}
	else
	{
		subscribe_params.notify = notify_func;
		subscribe_params.value = BT_GATT_CCC_INDICATE;
		subscribe_params.ccc_handle = attr->handle;

		err = bt_gatt_subscribe(conn, &subscribe_params);
		if (err && err != -EALREADY)
		{
			printk("Subscribe failed (err %d)\n", err);
		}
		else
		{
			printk("[SUBSCRIBED]\n");
		}

		return BT_GATT_ITER_STOP;
	}

	return BT_GATT_ITER_STOP;
}

// static bool eir_found(struct bt_data *data, void *user_data)
// {
	
// 	bt_addr_le_t *addr = user_data;
// 	char name[NAME_LEN];

// 	uint8_t len;
// 	int err1;
// 	struct bt_le_conn_param *param_spo2;
// 	(void)memset(name, 0, sizeof(name));

// 	printk("[AD]: %u data_len %u\n", data->type, data->data_len);

// 	switch (data->type) {

// 		case BT_DATA_NAME_SHORTENED:
// 		case BT_DATA_NAME_COMPLETE:
// 			len = MIN(data->data_len, NAME_LEN - 1);
// 			(void)memcpy(name, data->data, len);
// 			name[len] = '\0';
// 			if((memcmp(SPO2_NAME,name,sizeof(SPO2_NAME)))==0){
// 				err1 = bt_le_scan_stop();

// 				if (err1) {
// 					printk("Stop LE scan failed (err %d)\n", err1);
// 				}
// 				param_spo2 = BT_LE_CONN_PARAM_DEFAULT;
// 				err1 = bt_conn_le_create(addr, BT_CONN_LE_CREATE_CONN,
// 										param_spo2, &default_conn);
// 				if (err1) {
// 					printk("Create conn failed (err %d)\n", err1);
// 					start_scan();
// 				}

// 				return false;
// 		 	}
// 		default:	return true;
// 	}

// 	return true;
// }

static bool eir_found(struct bt_data *data, void *user_data)
{
	bt_addr_le_t *addr = user_data;
	int i;

	printk("[AD]: %u data_len %u\n", data->type, data->data_len);

	switch (data->type) {
	case BT_DATA_UUID16_SOME:
	case BT_DATA_UUID16_ALL:
		if (data->data_len % sizeof(uint16_t) != 0U) {
			printk("AD malformed\n");
			return true;
		}

		for (i = 0; i < data->data_len; i += sizeof(uint16_t)) {
			struct bt_uuid *uuid;
			uint16_t u16;
			int err;

			memcpy(&u16, &data->data[i], sizeof(u16));
			uuid = BT_UUID_DECLARE_16(sys_le16_to_cpu(u16));
			if (bt_uuid_cmp(uuid, BT_UUID_HTS)) {
				continue;
			}

			err = bt_le_scan_stop();
			if (err) {
				printk("Stop LE scan failed (err %d)\n", err);
				continue;
			}

			err = bt_conn_le_create(addr, BT_CONN_LE_CREATE_CONN,
						BT_LE_CONN_PARAM_DEFAULT,
						&default_conn);
			if (err) {
				printk("Create connection failed (err %d)\n",
				       err);
				scan_start();
			}

			return false;
		}
	}

	return true;
}

static void device_found(const bt_addr_le_t *addr, int8_t rssi, uint8_t type,
			 struct net_buf_simple *ad)
{
	char dev[BT_ADDR_LE_STR_LEN];
	int err;

	if(bt_addr_le_cmp(BT_TEMPERATURE_ADDR_LE_ANY,addr) == 0){

		bt_addr_le_to_str(addr, dev, sizeof(dev));
		
		printk("\n");
		printk("[DEVICE]: %s, AD evt type %u, AD data len %u, RSSI %i\n",
			dev, type, ad->len, rssi);
		
		/* We're only interested in connectable events */
		// if (type == BT_GAP_ADV_TYPE_ADV_IND ||
		// 	type == BT_GAP_ADV_TYPE_ADV_DIRECT_IND) {
		// 	bt_data_parse(ad, eir_found, (void *)addr);
		// }
		err = bt_le_scan_stop();
		if (err) {
			printk("Stop LE scan failed (err %d)\n", err);
		}

		err = bt_conn_le_create(addr, BT_CONN_LE_CREATE_CONN,
					BT_LE_CONN_PARAM_DEFAULT,
					&default_conn);
		if (err) {
			printk("Create connection failed (err %d)\n",
					err);
			start_scan();
		}
	}else{
		//printk("CMP failed\n");
	}
}

static void start_scan(void)
{
	int err;

	/* Use active scanning and disable duplicate filtering to handle any
	 * devices that might update their advertising data at runtime. */
	struct bt_le_scan_param scan_param = {
		.type       = BT_LE_SCAN_TYPE_ACTIVE,
		.options    = BT_LE_SCAN_OPT_NONE,
		.interval   = BT_GAP_SCAN_FAST_INTERVAL,
		.window     = BT_GAP_SCAN_FAST_WINDOW,
	};

	err = bt_le_scan_start(&scan_param, device_found);
	if (err)
	{
		printk("Scanning failed| Unable to load scan parameters\n");
		return;
	}
	printk("Scanning Start Sucessfull\n");
}

static void connected(struct bt_conn *conn, uint8_t conn_err)
{

	int err;
	char addr[BT_ADDR_LE_STR_LEN];

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

	if (conn_err) {
		printk("Failed to connect to %s (%u)\n", addr, conn_err);

		bt_conn_unref(default_conn);
		default_conn = NULL;

		start_scan();
		return;
	}

	printk("Connected: %s\n",addr);
	
	if (conn == default_conn)
	{
		
		memcpy(&uuid, BT_UUID_TEMPERATURE_ALERT_SERVICE , sizeof(uuid));
		discover_params.uuid = &uuid.uuid;
		discover_params.func = discover_func;
		discover_params.start_handle = BT_ATT_FIRST_ATTRIBUTE_HANDLE;
		discover_params.end_handle = BT_ATT_LAST_ATTRIBUTE_HANDLE;
		discover_params.type = BT_GATT_DISCOVER_PRIMARY;

		err = bt_gatt_discover(default_conn, &discover_params);
		if (err) {
			printk("Discover failed(err %d)\n", err);
			return;
		}
	}
}

static void disconnected(struct bt_conn *conn, uint8_t reason)
{
	char addr[BT_ADDR_LE_STR_LEN];

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

	printk("Disconnected: %s (reason 0x%02x)\n", addr, reason);

	if (default_conn != conn) {
		return;
	}

	bt_conn_unref(default_conn);
	default_conn = NULL;

	start_scan();
}

BT_CONN_CB_DEFINE(conn_callbacks) = {
	.connected = connected,
	.disconnected = disconnected,
};

void main(void)
{
	int err;
	err = bt_enable(NULL);

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

	printk("Bluetooth initialized\n");

	start_scan();
}
#endif

t notify and indicate function .But i didnt get the data in notify and indicate function. i am add the code and log files

Fullscreen BLE_LOG_DEC_30.txt Download

*** Booting Zephyr OS build v3.1.99-ncs1-1  ***
init main
[Bluetooth initialized
Scanning successfully started
00:00:00.005,493] <inf> sdc_hci_driver: SoftDevice Controller build revision:
                                         29 5c 92 f1 36 81 92 d1  b7 a9 f0 f1 99 e9 4c 19 |)\..6... ......L.
                                         1f 23 83 4a                                      |.#.J
[00:00:00.008,911] <inf> bt_hci_core: HW Platform: Nordic Semiconductor (0x0002)
[00:00:00.008,941] <inf> bt_hci_core: HW Variant: nRF52x (0x0002)
[00:00:00.008,972] <inf> bt_hci_core: Firmware: Standard Bluetooth controller (0x00) Version 41.37468 Build 2457941745
[00:00:00.010,314] <inf> bt_hci_core: Identity: F0:CF:29:9D:9B:96 (random)
[00:00:00.010,314] <inf> bt_hci_core: HCI: version 5.3 (0x0c) revision 0x11d8, manufacturer 0x0059
[00:00:00.010,345] <inf> bt_hci_core: LMP: version 5.3 (0x0c) subver 0x11d8
[DEVICE]: E4:38:55:AE:4D:EE (random), AD evt type 0, AD data len 26, RSSI -55
[AD]: 25 data_len 2
[AD]: 1 data_len 1
[AD]: 3 data_len 6
Connected: E4:38:55:AE:4D:EE (random)
Battery [ATTRIBUTE] handle 13
Battery characteristics [SUBSCRIBED]
temperature [ATTRIBUTE] handle 38
Battery notify

temperature [ATTRIBUTE] handle 39
temperature [ATTRIBUTE] handle 41
temperature measurement [SUBSCRIBED]
Temperature notify

position [ATTRIBUTE] handle 42
position [ATTRIBUTE] handle 43
position [ATTRIBUTE] handle 45
position characteristics [SUBSCRIBED]
Position notify

alert [ATTRIBUTE] handle 9
alert [ATTRIBUTE] handle 10
alert [ATTRIBUTE] handle 12
Alert characteristics [SUBSCRIBED]
Alert notify

fev alert [ATTRIBUTE] handle 17
fev alert [ATTRIBUTE] handle 18
bt write start
Write sucess
fev alert [ATTRIBUTE] handle 20
CTS [ATTRIBUTE] handle 20
CTS [ATTRIBUTE] handle 21
before write CTS
length  a
e6  7  c 1d  c  1  0  1  0  0

after Write CTS sucess
length  a
e6  7  c 1d  c  1  0  1  0  0


Disconnected



Disconnected



Disconnected



Disconnected



Disconnected



Disconnected

Connected via Serial Port with settings /dev/ttyACM0 115200 8n1 rtscts:off

temperature [ATTRIBUTE] handle 38
Battery notify

temperature [ATTRIBUTE] handle 39
temperature [ATTRIBUTE] handle 41
temperature measurement [SUBSCRIBED]
Temperature notify

position [ATTRIBUTE] handle 42
position [ATTRIBUTE] handle 43
position [ATTRIBUTE] handle 45
position characteristics [SUBSCRIBED]
Position notify

alert [ATTRIBUTE] handle 9
alert [ATTRIBUTE] handle 10
alert [ATTRIBUTE] handle 12
Alert characteristics [SUBSCRIBED]
Alert notify

fev alert [ATTRIBUTE] handle 17
fev alert [ATTRIBUTE] handle 18
bt write start
Write sucess
fev alert [ATTRIBUTE] handle 20
CTS [ATTRIBUTE] handle 20
CTS [ATTRIBUTE] handle 21
before write CTS
length  a
e6  7  c 1f  7  d 21  1  0  0

after Write CTS sucess
length  a
e6  7  c 1d  c  1  0  1  0  0
*** Booting Zephyr OS build v3.1.99-ncs1-1  ***
init main
[Bluetooth initialized
Scanning successfully started
00:00:00.005,462] <inf> sdc_hci_driver: SoftDevice Controller build revision:
                                         29 5c 92 f1 36 81 92 d1  b7 a9 f0 f1 99 e9 4c 19 |)\..6... ......L.
                                         1f 23 83 4a                                      |.#.J
[00:00:00.008,850] <inf> bt_hci_core: HW Platform: Nordic Semiconductor (0x0002)
[00:00:00.008,911] <inf> bt_hci_core: HW Variant: nRF52x (0x0002)
[00:00:00.008,911] <inf> bt_hci_core: Firmware: Standard Bluetooth controller (0x00) Version 41.37468 Build 2457941745
[00:00:00.010,253] <inf> bt_hci_core: Identity: F0:CF:29:9D:9B:96 (random)
[00:00:00.010,284] <inf> bt_hci_core: HCI: version 5.3 (0x0c) revision 0x11d8, manufacturer 0x0059
[00:00:00.010,314] <inf> bt_hci_core: LMP: version 5.3 (0x0c) subver 0x11d8
[DEVICE]: E4:38:55:AE:4D:EE (random), AD evt type 0, AD data len 26, RSSI -49
[AD]: 25 data_len 2
[AD]: 1 data_len 1
[AD]: 3 data_len 6
Connected: E4:38:55:AE:4D:EE (random)
Battery [ATTRIBUTE] handle 13
Battery characteristics [SUBSCRIBED]
temperature [ATTRIBUTE] handle 38
Battery notify

temperature [ATTRIBUTE] handle 39
temperature [ATTRIBUTE] handle 41
temperature measurement [SUBSCRIBED]
Temperature notify

position [ATTRIBUTE] handle 42
position [ATTRIBUTE] handle 43
position [ATTRIBUTE] handle 45
position characteristics [SUBSCRIBED]
Position notify

alert [ATTRIBUTE] handle 9
alert [ATTRIBUTE] handle 10
alert [ATTRIBUTE] handle 12
Alert characteristics [SUBSCRIBED]
Alert notify

fev alert [ATTRIBUTE] handle 17
fev alert [ATTRIBUTE] handle 18
bt write start
Write sucess
fev alert [ATTRIBUTE] handle 20
CTS [ATTRIBUTE] handle 20
CTS [ATTRIBUTE] handle 21
before write CTS
length  a
e6  7  c 1d  c  1  0  1  0  0

after Write CTS sucess
length  a
e6  7  c 1d  c  1  0  1  0  0

[Hung Bui]

Hi Goudam, 

Could you try to capture a sniffer trace ? We would need to verify if the characteristic CCCD attribute has been written or not. 
I would suggest to test with one single characteristic first before moving to multiple ones. 

Have you made sure the peripheral actually try to send notification ? 

Have you tried to test with the peripheral_uart and the central_uart ? Did they work for you ? 

[Goudam]

I did not use sniffer trace. However, in the NRF Connect app, I enabled the CCCD attribute, and it worked. How to Enable the CCCD attribute in Central

I've already tried with single characteristics, but the problem is that I need to subscribe and write for all of the services in order to get data, so I tried to subscribe to all of them.

I had already tried health rate measurement and it worked, so I continued in the same manner.

[Hung Bui]

Hi Goudam, 

If the device doesn't have any display or keyboard how did you pair with MITM protection with the phone ? 
Note that if only level 2 needed (no MITM ) then you can pair with Just work. 

I'm afraid that we can't really help you on this case as it's more about the behavior of a 3rd party device that we are not familiar with. 

What I can suggest you is to test using a peripheral (dummy device) that mimic the 3rd party device. So that you verify you can do all the task of connecting, service discovery, enable CCCD and can receive notification (from the dummy device) only after that you can start testing with the 3rd party device. You can then compare the trace between the dummy device and your central, vs the trace between the 3rd party device and your central. 

[Goudam]

Hi Hung,

On the vendor side, they mentioned that I should switch the security from L1 to L2 in sequence to subscribe to the battery,alert,position,human temperature measurement service, and then I should switch the security from L2 to L1 in order to write current time and fever threshold service, but switching from L2 to L1 never occurs; it is always in L2.

[Hung Bui]

Hi Goudam, 

The Bluetooth pairing always aim at highest possible pairing method. In this case if you have a display or keyboard it will try to do encryption with L2. 
But please clarify with me that you have a keyboard of display or static passkey with the sensor. You mentioned you didn't have that. Without keyboard/display/static passkey how did you do L2 ? 

Usually it shouldn't be an issue when doing a higher security level on a characteristic require lower level of security. Meaning if you are at L2 you can write to a characteristic requires L1. 

[Goudam]

We don't have a keyboard, monitor, or passkey. However, the vendor stated that the security should be changed from L2 to L1 for write to a characteristics. I tried the method listed below to set security; if security changes successfully, it calls the security changed function, but it does not indicate whether the security change was successful or unsuccessful. How do I set the passkey in L2?

err=bt_conn_set_security(conn, BT_SECURITY_L1);
if (err) {
 	printk("bt_conn_set_security failed (err %d)\n", err);
 	return;
}

.

[Goudam]

Is there another way to change the security level from high to low?

[Hung Bui]

If you don't have any keyboard or display on the device there isn't a way to do L2. 
Please ask the vendor how they do L2 without keyboard or display. 

Please answer, when you use NRF Connect on the phone and you connect to the sensor, did everything work as expected ? 

[Goudam]

We are checking with the vendor to see they are using Authentication with no MITM (ESP GATT AUTH REQ NO MITM) in esp, and  so, what level do I need to set to achieve the same level of security in our nordic.

[Hung Bui]

Hi Goudam, 

I think I made a mistake.  I just check the Bluetooth term again

Level 1 L1 is open no encryption/pairing. 

Level 2 L2 is encryption (pair) without authentication a.k.a Just work. 

As far as I know if a characteristic is open, it should be able to write to it even if the link is encrypted (L2). 
When the link is encrypted I don't think there is a way to switch back to open except for disconnecting. 

So what you need to do is to write to the characteristic with L1 requirement first, then you pair and then write to the characteristic require L2. 

[Goudam]

Hi HUNG ,

Now I'm getting data from the sensor, but there's one problem: disconnecting and reconnecting the vendor device isn't working. When I try to subscribe, I get the error EALREADY.

[Hung Bui]

Hi Goudam, 

If the 2 devices are bonded and you reconnect, you don't have to subscribe to the characteristic again as the CCCD may have been restored. 

Could you try in the code to call bt_gatt_resubscribe() instead of bt_gatt_subscribe()

Please try capture a sniffer trace. It will save you and save us a lot of time.