Sending MPU6050 sensor data through BLE (5340DK)

[YAZHINI]

 while Sending MPU6050 sensor data through BLE (5340DK) .In the nrf connect for mobile I am getting following data,sensor reading is not transferred propoerly In the vscode log it is showing correct reading when transferred though BLE and viewed in app below ouput comes.

 

MAIN.C 

#include <zephyr/kernel.h>

#include <zephyr/device.h>

#include <zephyr/drivers/sensor.h>

#include <zephyr/bluetooth/bluetooth.h>

#include <zephyr/bluetooth/conn.h>

#include <zephyr/bluetooth/gatt.h>

#include <zephyr/sys/byteorder.h>

/* UUIDs for the custom BLE service and characteristics */

#define CUSTOM_SERVICE_UUID BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x12345678, 0x1234, 0x5678, 0x1234, 0x123456789abc))

#define ACCEL_CHAR_UUID BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x12345678, 0x1234, 0x5678, 0x1234, 0xabcdefabcdef))

#define GYRO_CHAR_UUID BT_UUID_DECLARE_128(BT_UUID_128_ENCODE(0x12345678, 0x1234, 0x5678, 0x1234, 0x123456abcdef))

static struct bt_conn *current_conn;

/* GATT Characteristic values */

static uint8_t accel_data[12]; /* 3 axes, each 4 bytes (int32) */

static uint8_t gyro_data[12];

/* GATT Service Declaration */

BT_GATT_SERVICE_DEFINE(custom_svc,

    BT_GATT_PRIMARY_SERVICE(CUSTOM_SERVICE_UUID),

    BT_GATT_CHARACTERISTIC(ACCEL_CHAR_UUID,

        BT_GATT_CHRC_READ | BT_GATT_CHRC_NOTIFY,

        BT_GATT_PERM_READ, NULL, NULL, accel_data),

    BT_GATT_CCC(NULL, BT_GATT_PERM_READ | BT_GATT_PERM_WRITE),

    BT_GATT_CHARACTERISTIC(GYRO_CHAR_UUID,

        BT_GATT_CHRC_READ | BT_GATT_CHRC_NOTIFY,

        BT_GATT_PERM_READ, NULL, NULL, gyro_data),

    BT_GATT_CCC(NULL, BT_GATT_PERM_READ | BT_GATT_PERM_WRITE)

);

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_UUID128_ALL, BT_UUID_128_ENCODE(0x12345678, 0x1234, 0x5678, 0x1234, 0x123456789abc)),

};

void main(void) {

    const struct device *mpu6050;

    struct sensor_value accel[3], gyro[3];

    /* Initialize BLE */

    int err = bt_enable(NULL);

    if (err) {

        printk("Bluetooth init failed (err %d)\n", err);

        return;

    }

    printk("Bluetooth initialized\n");

    err = bt_le_adv_start(BT_LE_ADV_CONN_NAME, ad, ARRAY_SIZE(ad), NULL, 0);

    if (err) {

        printk("Advertising failed (err %d)\n", err);

        return;

    }

    printk("Advertising started\n");

    /* Initialize MPU6050 */

    mpu6050 = device_get_binding("MPU6050");

    if (!mpu6050) {

        printk("Error: Could not get MPU6050 device binding\n");

        return;

    }

    printk("MPU6050 initialized\n");

    while (1) {

        /* Fetch and send accelerometer and gyroscope data */

        if (sensor_sample_fetch(mpu6050) < 0) {

            printk("Error: Failed to fetch data from MPU6050\n");

            k_sleep(K_MSEC(1000));

            continue;

        }

        if (sensor_channel_get(mpu6050, SENSOR_CHAN_ACCEL_XYZ, accel) == 0) {

            sys_put_le32(accel[0].val1, &accel_data[0]);

            sys_put_le32(accel[1].val1, &accel_data[4]);

            sys_put_le32(accel[2].val1, &accel_data[8]);

        }

        if (sensor_channel_get(mpu6050, SENSOR_CHAN_GYRO_XYZ, gyro) == 0) {

            sys_put_le32(gyro[0].val1, &gyro_data[0]);

            sys_put_le32(gyro[1].val1, &gyro_data[4]);

            sys_put_le32(gyro[2].val1, &gyro_data[8]);

        }

        /* Notify connected devices */

        if (current_conn) {

            bt_gatt_notify(current_conn, &custom_svc.attrs[2], accel_data, sizeof(accel_data));

            bt_gatt_notify(current_conn, &custom_svc.attrs[5], gyro_data, sizeof(gyro_data));

        }

        /* Wait before next read */

        k_sleep(K_MSEC(1000));

    }

}

/* Connection callback */

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

    if (err) {

        printk("Connection failed (err %u)\n", err);

    } else {

        printk("Connected\n");

        current_conn = conn;

    }

}

static void disconnected(struct bt_conn *conn, uint8_t reason) {

    printk("Disconnected (reason %u)\n", reason);

    current_conn = NULL;

}

BT_CONN_CB_DEFINE(conn_callbacks) = {

    .connected = connected,

    .disconnected = disconnected,

};

PRJ.CONF

# Bluetooth Configuration

CONFIG_BT=y

CONFIG_BT_PERIPHERAL=y

# Enable I2C for sensor communication

CONFIG_I2C=y

CONFIG_I2C_LOG_LEVEL_DBG=y  # I2C logging at debug level

# Enable Sensor

CONFIG_SENSOR=y

CONFIG_MPU6050=y

# Enable logging (Log Level: 3 for info, 4 for debug)

CONFIG_LOG=y

CONFIG_LOG_DEFAULT_LEVEL=4  # Set logging level to debug

# Enable the Console for logging output via UART

CONFIG_CONSOLE=y

CONFIG_UART_CONSOLE=y

# Enable memory settings and stack size

CONFIG_MAIN_STACK_SIZE=1024

CONFIG_HEAP_MEM_POOL_SIZE=1024

# Bluetooth Configuration

CONFIG_BT=y

CONFIG_BT_PERIPHERAL=y

# Enable I2C for sensor communication

CONFIG_I2C=y

CONFIG_I2C_LOG_LEVEL_DBG=y  # I2C logging at debug level

# Enable Sensor

CONFIG_SENSOR=y

CONFIG_MPU6050=y

# Enable logging (Log Level: 3 for info, 4 for debug)

CONFIG_LOG=y

CONFIG_LOG_DEFAULT_LEVEL=4  # Set logging level to debug

# Enable the Console for logging output via UART

CONFIG_CONSOLE=y

CONFIG_UART_CONSOLE=y

# Enable memory settings and stack size

CONFIG_MAIN_STACK_SIZE=1024

CONFIG_HEAP_MEM_POOL_SIZE=1024

# Bluetooth Configuration

CONFIG_BT=y

CONFIG_BT_PERIPHERAL=y

# Enable I2C for sensor communication

CONFIG_I2C=y

CONFIG_I2C_LOG_LEVEL_DBG=y  # I2C logging at debug level

# Enable Sensor

CONFIG_SENSOR=y

CONFIG_MPU6050=y

# Enable logging (Log Level: 3 for info, 4 for debug)

CONFIG_LOG=y

CONFIG_LOG_DEFAULT_LEVEL=4  # Set logging level to debug

# Enable the Console for logging output via UART

CONFIG_CONSOLE=y

CONFIG_UART_CONSOLE=y

# Enable memory settings and stack size

CONFIG_MAIN_STACK_SIZE=1024

CONFIG_HEAP_MEM_POOL_SIZE=1024

LOG MESSAGES IN VSCODE
--- 19 messages dropped ---
[00:12:54.814,086] <dbg> bt_conn: bt_conn_tx_processor: no buf returned
[00:12:54.814,117] <dbg> bt_conn: bt_conn_unref: handle 47 ref 2 -> 1
[00:12:54.814,117] <dbg> bt_hci_core: tx_processor: TX process start
[00:12:54.814,147] <dbg> bt_conn: bt_conn_tx_processor: start
[00:12:54.814,178] <dbg> bt_conn: bt_conn_tx_processor: no connection wants to do stuff
--- 9 messages dropped ---
[00:12:54.844,726] <dbg> bt_conn: tx_notify_process: conn 0x200011c0
[00:12:54.844,757] <dbg> bt_conn: tx_notify_process: tx 0x200018d0 cb 0 user_data 0
[00:12:54.844,757] <dbg> bt_conn: tx_free: 0x200018d0
[00:12:54.844,787] <dbg> bt_conn: tx_notify_process: raise TX IRQ
[00:12:54.844,818] <dbg> bt_hci_core: bt_tx_irq_raise: kick TX
[00:12:54.844,848] <dbg> bt_hci_core: tx_processor: TX process start
[00:12:54.844,848] <dbg> bt_conn: bt_conn_tx_processor: start
[00:12:54.844,879] <dbg> bt_conn: bt_conn_tx_processor: no connection wants to do stuff
[00:12:54.844,909] <dbg> os: k_sched_unlock: scheduler unlocked (0x200008f8:0)
[00:12:54.844,940] <dbg> bt_hci_driver: bt_ipc_rx: RX buf payload:
33 68 83 01 00 |3h...
[00:12:54.892,791] <dbg> bt_hci_driver: bt_ipc_rx: ipc data:
04 13 05 01 2f 00 01 00 |..../...
[00:12:54.892,822] <dbg> bt_hci_driver: bt_ipc_evt_recv: len 5
[00:12:54.892,852] <dbg> bt_hci_driver: bt_ipc_rx: Calling bt_recv(0x200056ec)
[00:12:54.892,852] <dbg> bt_hci_core: bt_recv_unsafe: buf 0x200056ec len 7
[00:12:54.892,883] <dbg> bt_hci_core: hci_num_completed_packets: num_handles 1
[00:12:54.892,913] <dbg> bt_hci_core: hci_num_completed_packets: handle 47 count 1
[00:12:54.892,944] <dbg> bt_conn: bt_conn_ref: handle 47 ref 1 -> 2
[00:12:54.892,974] <dbg> bt_conn: bt_conn_unref: handle 47 ref 2 -> 1
[00:12:54.893,005] <dbg> os: k_sched_unlock: scheduler unlocked (0x200008f8:0)
[00:12:54.893,035] <dbg> bt_conn: tx_notify_process: conn 0x200011c0
[00:12:54.893,066] <dbg> bt_conn: tx_notify_process: tx 0x200018dc cb 0 user_data 0
[00:12:54.893,066] <dbg> bt_conn: tx_free: 0x200018dc
[00:12:54.893,096] <dbg> bt_conn: tx_notify_process: raise TX IRQ
[00:12:54.893,096] <dbg> bt_hci_core: bt_tx_irq_raise: kick TX
[00:12:54.893,157] <dbg> bt_hci_core: tx_processor: TX process start
[00:12:54.893,157] <dbg> bt_conn: bt_conn_tx_processor: start
[00:12:54.893,188] <dbg> bt_conn: bt_conn_tx_processor: no connection wants to do stuff
[00:12:54.893,218] <dbg> bt_hci_driver: bt_ipc_rx: RX buf payload:
94 5b 02 00 60 |.[..`
[00:12:55.818,176] <dbg> bt_hci_core: bt_send: buf 0x200057d0 len 23 type 2
--- 107 messages dropped ---
[00:12:55.818,695] <dbg> bt_hci_core: bt_tx_irq_raise: kick TX
[00:12:55.818,725] <dbg> bt_conn: bt_conn_tx_processor: no buf returned
[00:12:55.818,725] <dbg> bt_conn: bt_conn_unref: handle 47 ref 2 -> 1
[00:12:55.818,756] <dbg> bt_hci_core: tx_processor: TX process start
[00:12:55.818,786] <dbg> bt_conn: bt_conn_tx_processor: start
[00:12:55.818,817] <dbg> bt_conn: bt_conn_tx_processor: no connection wants to do stuff
--- 12 messages dropped ---
[00:12:55.819,793] <dbg> bt_conn: tx_notify_process: raise TX IRQ
[00:12:55.819,824] <dbg> bt_hci_core: bt_tx_irq_raise: kick TX
[00:12:55.819,854] <dbg> bt_hci_core: tx_processor: TX process start
[00:12:55.819,885] <dbg> bt_conn: bt_conn_tx_processor: start
[00:12:55.819,915] <dbg> bt_conn: bt_conn_tx_processor: no connection wants to do stuff
[00:12:55.819,946] <dbg> os: k_sched_unlock: scheduler unlocked (0x200008f8:0)
[00:12:55.819,976] <dbg> bt_hci_driver: bt_ipc_rx: RX buf payload:
ca e8 83 01 58 |....X
[00:12:55.867,828] <dbg> bt_hci_driver: bt_ipc_rx: ipc data:
04 13 05 01 2f 00 01 00 |..../...
[00:12:55.867,828] <dbg> bt_hci_driver: bt_ipc_evt_recv: len 5
[00:12:55.867,858] <dbg> bt_hci_driver: bt_ipc_rx: Calling bt_recv(0x200056ec)
[00:12:55.867,889] <dbg> bt_hci_core: bt_recv_unsafe: buf 0x200056ec len 7
[00:12:55.867,889] <dbg> bt_hci_core: hci_num_completed_packets: num_handles 1
[00:12:55.867,919] <dbg> bt_hci_core: hci_num_completed_packets: handle 47 count 1
[00:12:55.867,950] <dbg> bt_conn: bt_conn_ref: handle 47 ref 1 -> 2
[00:12:55.867,980] <dbg> bt_conn: bt_conn_unref: handle 47 ref 2 -> 1
[00:12:55.868,041] <dbg> bt_conn: tx_notify_process: conn 0x200011c0
[00:12:55.868,041] <dbg> bt_conn: tx_notify_process: tx 0x200018d0 cb 0 user_data 0
[00:12:55.868,072] <dbg> bt_conn: tx_free: 0x200018d0
[00:12:55.868,103] <dbg> bt_conn: tx_notify_process: raise TX IRQ
[00:12:55.868,103] <dbg> bt_hci_core: bt_tx_irq_raise: kick TX
[00:12:55.868,133] <dbg> bt_hci_core: tx_processor: TX process start
[00:12:55.868,164] <dbg> bt_conn: bt_conn_tx_processor: start
[00:12:55.868,164] <dbg> bt_conn: bt_conn_tx_processor: no connection wants to do stuff
[00:12:55.868,225] <dbg> os: k_sched_unlock: scheduler unlocked (0x200008f8:0)
[00:12:55.868,255] <dbg> bt_hci_driver: bt_ipc_rx: RX buf payload:
00 21 00 00 20 |.!..
[00:12:56.822,814] <dbg> bt_hci_core: bt_send: buf 0x200057d0 len 23 type 2
--- 87 messages dropped ---
[00:12:56.822,845] <dbg> bt_hci_driver: bt_ipc_send: buf 0x200057d0 type 2 len 23
[00:12:56.822,875] <dbg> bt_hci_driver: bt_ipc_send: Final HCI buffer:
02 2f 00 13 00 0f 00 04 00 1b 15 00 00 00 00 00 |./...... ........
00 00 00 00 00 00 00 00 |........
--- 19 messages dropped ---
[00:12:56.823,364] <dbg> bt_conn: bt_conn_tx_processor: no buf returned
[00:12:56.823,394] <dbg> bt_conn: bt_conn_unref: handle 47 ref 2 -> 1
[00:12:56.823,425] <dbg> bt_hci_core: tx_processor: TX process start
--- 14 messages dropped ---
[00:12:56.843,566] <dbg> bt_conn: tx_notify_process: raise TX IRQ
[00:12:56.843,566] <dbg> bt_hci_core: bt_tx_irq_raise: kick TX
[00:12:56.843,597] <dbg> bt_hci_core: tx_processor: TX process start
[00:12:56.843,627] <dbg> bt_conn: bt_conn_tx_processor: start
[00:12:56.843,658] <dbg> bt_conn: bt_conn_tx_processor: no connection wants to do stuff
[00:12:56.843,688] <dbg> os: k_sched_unlock: scheduler unlocked (0x200008f8:0)
[00:12:56.843,719] <dbg> bt_hci_driver: bt_ipc_rx: RX buf payload:
00 19 00 00 38 |....8
[00:12:56.891,571] <dbg> bt_hci_driver: bt_ipc_rx: ipc data:
04 13 05 01 2f 00 01 00 |..../...
[00:12:56.891,601] <dbg> bt_hci_driver: bt_ipc_evt_recv: len 5
[00:12:56.891,632] <dbg> bt_hci_driver: bt_ipc_rx: Calling bt_recv(0x200056ec)
[00:12:56.891,662] <dbg> bt_hci_core: bt_recv_unsafe: buf 0x200056ec len 7
[00:12:56.891,693] <dbg> bt_hci_core: hci_num_completed_packets: num_handles 1
[00:12:56.891,693] <dbg> bt_hci_core: hci_num_completed_packets: handle 47 count 1
[00:12:56.891,723] <dbg> bt_conn:

   
How to rectify this error  rectify this and get proper reading App

[Kenneth]

Hello,

You need to enable notifications (subscribe) from the characteristics you want to receive data from (see three inbound arrow icons) when you are connected to a device in nRF Connect for mobile app:
https://nordicsemiconductor.github.io/IOS-nRF-Connect/assets/files/UserManual.pdf 

For debugging you might want to try to send a fixed array data for accel_data and gyro_data.

Kenneth

[YAZHINI]

I had enabled the notifications (3 inbound arrows)   but I received same output

  /* Notify connected devices with the updated data */

        if (current_conn) {

            if (bt_gatt_is_subscribed(&custom_svc.attrs[1], current_conn, BT_GATT_CCC_NOTIFY))

             {

             

                  bt_gatt_notify(current_conn, &custom_svc.attrs[1], accel_data, sizeof(accel_data));

            }

            if (bt_gatt_is_subscribed(&custom_svc.attrs[3], current_conn, BT_GATT_CCC_NOTIFY)) {

                bt_gatt_notify(current_conn, &custom_svc.attrs[3], gyro_data, sizeof(gyro_data));

               

            }

        }                   should I do anything in this part of code as it is notifying part    or sensor reading format part

[Kenneth]

You can check if there is any error code from bt_gatt_notify, and also add some log output just to ensure you are sending the expected data.

Kenneth

[YAZHINI]

the data being notified through BLE is not as expected.

[YAZHINI]

Any update...[00:00:01.535,858] <err> bt_hci_driver: Endpoint binding failed with -11
[00:00:01.543,182] <err> bt_hci_core: HCI driver open failed (-11)
Bluetooth init failed (err -11)              what is suitable headerfiles and prj.conf files                        

#include <zephyr/kernel.h>

#include <zephyr/device.h>

#include <zephyr/drivers/sensor.h>

#include <zephyr/bluetooth/bluetooth.h>

#include <zephyr/bluetooth/conn.h>

#include <zephyr/bluetooth/gatt.h>

#include <zephyr/sys/byteorder.h>

#include <zephyr/bluetooth/hci.h>                             

#include <zephyr/bluetooth/conn.h>

#include <zephyr/bluetooth/uuid.h>

#include <zephyr/bluetooth/gatt.h>

#include <zephyr/sys/printk.h>

# Bluetooth stack and HCI

CONFIG_BT=y

CONFIG_BT_PERIPHERAL=y

CONFIG_BT_DEVICE_NAME="MPU6050 Sensor"

CONFIG_BT_HCI_DRIVER_LOG_LEVEL_DBG=y

CONFIG_BT_HCI=y

  # Optional, for central role support

# Logging

CONFIG_LOG=y

CONFIG_LOG_MODE_IMMEDIATE=y

CONFIG_LOG_DEFAULT_LEVEL=3

CONFIG_LOG_DEFAULT_LEVEL=4

# I2C and Sensor support

CONFIG_I2C=y

CONFIG_SENSOR=y

CONFIG_MPU6050=y

# Main thread and system workqueue stack size

CONFIG_MAIN_STACK_SIZE=4096

CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=4096                    this what curently used ....why Host and Controller couldn.t able to bind