2 BLE devices but showing one in BLE mobile apps

satyam9896 · ‎2025-08-06

Hello everyone,

I’m using two STM32 MCU on baord with (BlueNRG-MS) stacked within, each running the same firmware that have BD_ADDR . When I power both boards on, I expect to see two separate entries in scanner apps like LightBlue or nRF Connect—but I only ever see a single device listed.

I tried to change the local advertising name but only one board im able to see it at once, it seems bcz of their similar uuid it is like that.

I’m looking for guidance on:

How to ensure each BlueNRG-MS module truly advertises with its own distinct address
Whether there are any special steps or best practices for writing a random static address via aci_hal_write_config_data(CONFIG_DATA_RANDOM_ADDRESS_OFFSET, …)
Scanner-side settings (e.g. duplicate filtering) or firmware tweaks that will guarantee all devices appear simultaneously
I have added the bluenrg c file for better understanding and solution

/**
  ******************************************************************************
  * File Name          : app_bluenrg_ms.c
  * Description        : Source file
  *
  ******************************************************************************
  *
  * COPYRIGHT 2020 STMicroelectronics
  *
  * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
  * You may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *        http://www.st.com/software_license_agreement_liberty_v2
  *
  * Unless required by applicable law or agreed to in writing, software 
  * distributed under the License is distributed on an "AS IS" BASIS, 
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  ******************************************************************************
  */

/* Includes ------------------------------------------------------------------*/
#include "app_bluenrg_ms.h"

#include "hci_tl.h"
#include "sample_service.h"
#include "role_type.h"
#include "bluenrg_utils.h"
#include "bluenrg_gatt_server.h"
#include "bluenrg_gap_aci.h"
#include "bluenrg_gatt_aci.h"
#include "bluenrg_hal_aci.h"

/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* Private defines -----------------------------------------------------------*/
/**
 * Define the role here only if it is not already defined in the project options
 * For the CLIENT_ROLE comment the line below 
 * For the SERVER_ROLE uncomment the line below
 */
#define SERVER_ROLE

#define BDADDR_SIZE 6
 
/* Private macros ------------------------------------------------------------*/

/* Private variables ---------------------------------------------------------*/
uint8_t bnrg_expansion_board = IDB04A1; /* at startup, suppose the X-NUCLEO-IDB04A1 is used */  
static volatile uint8_t user_button_init_state = 1;
static volatile uint8_t user_button_pressed = 0;

#ifdef SERVER_ROLE
  BLE_RoleTypeDef BLE_Role = SERVER;
#else
  BLE_RoleTypeDef BLE_Role = CLIENT;
#endif

extern volatile uint8_t set_connectable;
extern volatile int     connected;
extern volatile uint8_t notification_enabled;

extern volatile uint8_t end_read_tx_char_handle;
extern volatile uint8_t end_read_rx_char_handle;

/* USER CODE BEGIN PV */
uint8_t    Uart_TX_Buffer[3], Battery_Percentage[3];
/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
static void User_Process(void);
static void User_Init(void);

/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

#if PRINT_CSV_FORMAT
extern volatile uint32_t ms_counter;
/**
 * @brief  This function is a utility to print the log time
 *         in the format HH:MM:SS:MSS (DK GUI time format)
 *   None
 * @retval None
 */
void print_csv_time(void){
  uint32_t ms = HAL_GetTick();
  PRINT_CSV("%02ld:%02ld:%02ld.%03ld", ms/(60*60*1000)%24, ms/(60*1000)%60, (ms/1000)%60, ms%1000);
}
#endif

void MX_BlueNRG_MS_Init(void)
{
  /* USER CODE BEGIN SV */ 

  /* USER CODE END SV */
  
  /* USER CODE BEGIN BlueNRG_MS_Init_PreTreatment */
  
  /* USER CODE END BlueNRG_MS_Init_PreTreatment */

  /* Initialize the peripherals and the BLE Stack */
  uint8_t CLIENT_BDADDR[] = {0xbb, 0x00, 0x00, 0xE1, 0x80, 0x02};
  uint8_t SERVER_BDADDR[] = {0xaa, 0x00, 0x00, 0xE1, 0x80, 0x02};
  uint8_t bdaddr[BDADDR_SIZE];
  uint16_t service_handle, dev_name_char_handle, appearance_char_handle;
  
  uint8_t  hwVersion;
  uint16_t fwVersion;
  int ret;
  
  User_Init();
  
  /* Get the User Button initial state */
  user_button_init_state = BSP_PB_GetState(BUTTON_KEY);
  
  hci_init(user_notify, NULL);
      
  /* get the BlueNRG HW and FW versions */
  getBlueNRGVersion(&hwVersion, &fwVersion);

  /* 
   * Reset BlueNRG again otherwise we won't
   * be able to change its MAC address.
   * aci_hal_write_config_data() must be the first
   * command after reset otherwise it will fail.
   */
  hci_reset();
  
  HAL_Delay(100);
  
 // printf("HWver %d, FWver %d\n", hwVersion, fwVersion);
  
  if (hwVersion > 0x30) { /* X-NUCLEO-IDB05A1 expansion board is used */
    bnrg_expansion_board = IDB05A1; 
  }
  
  if (BLE_Role == CLIENT) {
    BLUENRG_memcpy(bdaddr, CLIENT_BDADDR, sizeof(CLIENT_BDADDR));
  } else {
    BLUENRG_memcpy(bdaddr, SERVER_BDADDR, sizeof(SERVER_BDADDR));
  }
  
  ret = aci_hal_write_config_data(CONFIG_DATA_PUBADDR_OFFSET,
                                  CONFIG_DATA_PUBADDR_LEN,
                                  bdaddr);
  if (ret) {
    //printf("Setting BD_ADDR failed 0x%02x.\n", ret);
  }
  
  ret = aci_gatt_init();    
  if (ret) {
   // printf("GATT_Init failed.\n");
  }
  
  if (BLE_Role == SERVER) {
    if (bnrg_expansion_board == IDB05A1) {
      ret = aci_gap_init_IDB05A1(GAP_PERIPHERAL_ROLE_IDB05A1, 0, 0x07, &service_handle, &dev_name_char_handle, &appearance_char_handle);
    }
    else {
      ret = aci_gap_init_IDB04A1(GAP_PERIPHERAL_ROLE_IDB04A1, &service_handle, &dev_name_char_handle, &appearance_char_handle);
    }
  }
  else {
    if (bnrg_expansion_board == IDB05A1) {
      ret = aci_gap_init_IDB05A1(GAP_CENTRAL_ROLE_IDB05A1, 0, 0x07, &service_handle, &dev_name_char_handle, &appearance_char_handle);
    }
    else {
      ret = aci_gap_init_IDB04A1(GAP_CENTRAL_ROLE_IDB04A1, &service_handle, &dev_name_char_handle, &appearance_char_handle);
    }
  }
  
  if (ret != BLE_STATUS_SUCCESS) {
    //printf("GAP_Init failed.\n");
  }
    
  ret = aci_gap_set_auth_requirement(MITM_PROTECTION_REQUIRED,
                                     OOB_AUTH_DATA_ABSENT,
                                     NULL,
                                     7,
                                     16,
                                     USE_FIXED_PIN_FOR_PAIRING,
                                     12345678,
                                     BONDING);
  if (ret == BLE_STATUS_SUCCESS) {
    //printf("BLE Stack Initialized.\n");
  }
  
  if (BLE_Role == SERVER) {
    //printf("SERVER: BLE Stack Initialized\n");
    ret = Add_Sample_Service();
    
   // if (ret == BLE_STATUS_SUCCESS)
      //printf("Service added successfully.\n");
    //else
      //printf("Error while adding service.\n");
    
  } //else {
    //printf("CLIENT: BLE Stack Initialized\n");
 // }
  
  /* Set output power level */
  ret = aci_hal_set_tx_power_level(1,4);

  /* USER CODE BEGIN BlueNRG_MS_Init_PostTreatment */
  
  /* USER CODE END BlueNRG_MS_Init_PostTreatment */
}

/*
 * BlueNRG-MS background task
 */
void MX_BlueNRG_MS_Process(void)
{
  /* USER CODE BEGIN BlueNRG_MS_Process_PreTreatment */
  
  /* USER CODE END BlueNRG_MS_Process_PreTreatment */
  
  User_Process();  
  hci_user_evt_proc();

  /* USER CODE BEGIN BlueNRG_MS_Process_PostTreatment */
  
  /* USER CODE END BlueNRG_MS_Process_PostTreatment */
}

/**
 * @brief  Initialize User process.
 *
 *   None
 * @retval None
 */
static void User_Init(void)
{
  BSP_PB_Init(BUTTON_KEY, BUTTON_MODE_EXTI);
  BSP_LED_Init(LED2);
    
  BSP_COM_Init(COM1); 
}

/**
 * @brief  Configure the device as Client or Server and manage the communication
 *         between a client and a server.
 *
 *   None
 * @retval None
 */
static void User_Process(void)
{
  if (set_connectable) 
  {
    /* Establish connection with remote device */
    Make_Connection();
    set_connectable = FALSE;
    user_button_init_state = BSP_PB_GetState(BUTTON_KEY);
  }
  
  if (BLE_Role == CLIENT) 
  {
    /* Start TX handle Characteristic dynamic discovery if not yet done */
    if (connected && !end_read_tx_char_handle){
      startReadTXCharHandle();
    }
    /* Start RX handle Characteristic dynamic discovery if not yet done */
    else if (connected && !end_read_rx_char_handle){      
      startReadRXCharHandle();
    }
    
    if (connected && end_read_tx_char_handle && end_read_rx_char_handle && !notification_enabled) 
    {
      BSP_LED_Off(LED2); //end of the connection and chars discovery phase
      enableNotification();
    }
  }  

  /* Check if the User Button has been pushed */
//  if (user_button_pressed) 
//  {
//    /* Debouncing */
//    HAL_Delay(50);
//    
//    /* Wait until the User Button is released */
//    while (BSP_PB_GetState(BUTTON_KEY) == !user_button_init_state);
//    
//    /* Debouncing */
//    HAL_Delay(50);
//    
//    if (connected && notification_enabled)
//    {
//      /* Send a toggle command to the remote device */
//      uint8_t data[20] = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F','G','H','I','J'};
      if(Uart_TX_Buffer[0] != 0x00 && Uart_TX_Buffer[0] != '0')
			{
				sendData(&Uart_TX_Buffer[0], sizeof(Uart_TX_Buffer));
				Uart_TX_Buffer[0] = '0';
			}  
	    //sendBatteryData(& Battery_Percentage[0], sizeof( Battery_Percentage));
        
      //BSP_LED_Toggle(LED2);  /* Toggle the LED2 locally. */
                               /* If uncommented be sure the BSP_LED_Init(LED2)
                                * is called in main().
                                * E.g. it can be enabled for debugging. */
//    }
//    
//    /* Reset the User Button flag */
//    user_button_pressed = 0;
//  } 
}

/**
  * @brief  BSP Push Button callback
  *   Button Specifies the pin connected EXTI line
  * @retval None.
  */
void BSP_PB_Callback(Button_TypeDef Button)
{
  /* Set the User Button flag */
  user_button_pressed = 1;
}

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

Any clear examples or recommended ST-approved patterns for multi-device BLE deployments would be greatly appreciated.

Thank you!

satyam9896 · ‎2025-08-06

Can anyone please help me out for this ?