STM32WBA Bluetooth^® LE – Peer 2 Peer Applications

This message will disappear after all relevant tasks have been resolved.

Semantic MediaWiki

There are 1 incomplete or pending task to finish installation of Semantic MediaWiki. An administrator or user with sufficient rights can complete it. This should be done before adding new data to avoid inconsistencies.

1. Peer to Peer Profile

The Peer to Peer Profile is a Generic Attribute Profile (GATT) based low-energy profile defined by STMicroelectronics with proprietary UUIDs(128 bits)
The Peer to Peer Profile, widely used for direct connection, defines the communication between a GATT-server of a Peer to Peer Server device, and a GATT-client Collector device, such as a smartphone, STM32WBA Peer to Peer Client or Peer to Peer Router devices.

The Peer to Peer Server:
- Contains the P2P Service, which expose two characteristics (Notification & Write) in order to create a bi-direction data communication.
- Is the GATT server.
The Collector:
- Accesses the information exposed by Peer to Peer Server, controls it with the Write characteristics, receives Notification from it.
- Is the GATT client.

This wiki page is the description of the Peer to Peer Server and Peer to Peer Client projects provided within the STM32CubeWBA MCU Package^[1]

Follow this "link" for Peer to Peer Router project explanation.

Bluetooth^® LE Peer to Peer Profile & STM32WBA

1.1. STM32WBA Peer to Peer Server application

The table below describes the structure of Peer to Peer service:

Bluetooth^® LE Peer to Peer Service specification

Service	Characteristic	Mode	UUID	size
P2P Service			0000FE40-cc7a-482a-984a-7f2ed5b3e58f
	LED	Write without Response/Read	0000FE41-8e22-4541-9d4c-21edae82ed19	2
	SWITCH	Notify	0000FE42-8e22-4541-9d4c-21edae82ed19	2

Peer To Peer Server is exported as a Service

LED characteristic:
- Used to control LED1 (Blue) on STM32WBA platform by remote device .

Peer to Peer Service - LED Characteristic

Byte Index	0	1
Name	LED Selection	LED Level
Value	0x01: blue LED	0x00: LEDoff 0x01: LEDon

SWITCH Characteristic:
- Used to switch LED or Lamp on Collector device.

Peer to Peer Service - SWITCH Characteristic

Byte Index	0	1
Name	Button Selection	Status
Value	0x01: button1	0x00 or 0x01

Example of flow diagram between STM32WBA & ST BLE Toolbox

At start up, Peer To Peer Server application starts Advertising including the Manufacturer Advertising Elements as described below:

	0	1	2-3	4	5	6	7	8	9	10-15
	Length	Manufacturer ID	Company	BlueSTSDK Version	Device ID	Firmware ID	Option 1	Option 2	Option 3	Device Address
P2P Server	0x0F	0xFF	0x0030 STMicro	0x02	0x8B Nucleo-WBA	0x83	0x00	0x00	0x00	0x08E12Axxxx

Advertising is stopped after 30s, pressing B1 restart it.

1.2. STM32WBA Peer to Peer Client application

It acts as a Central device with the support of GATT Client Layer.
At start up, by pressing B1 button, Peer To Peer Client application:

Starts scanning to detect Peer To Peer Sever application by filtering the Firmware ID of the STMicroelectronics Manufacturer advertising data
Stops Scanning once P2P server detected
Connects to the P2P Server to establish the connection.
Discovers GATT Service & Characteristics of the P2P server
Enable all GATT server notification characteristics

Once connected, the Peer To Peer Client application:

by pressing B1 button, write a message to toggle the Blue LED of the P2P Server
Receive notification to toggle the on board Blue LED from remote P2P Server Application.

Example of flow diagram between STM32WBA P2P Server & P2P Client

1.3. On board buttons configuration

P2P Applications Nucleo-WBA buttons configuration

Application	Condition	B1 Click	B1 Long Press	B2 Click	B2 Long Press	B3 Click	B3 Long Press
P2P Server	Idle Connected	Adv start Notification		Clear Sec db Adv start (Multi conn)		L2CAP CONN REQ
P2P Client	Idle Connected	Start Scan Write Char		Clear Sec db -		Change Conn Int

2. Requirements

2.1. Software and system requirements

The software required are the following (minimum IDEs version):

IAR Embedded Workbench for ARM (EWARM) toolchain V??
RealView Microcontroller Development Kit (MDK-ARM) toolchain V??
STM32CubeIDE toolchain V?? ^[2].

Programmer:

STM32CubeProgrammer^[3] : To flash the board with an already generated binary

2.2. Hardware requirements

NUCLEO-WBA5 ^[4] is necessary to install the application.

Hardware platform illustration

2.3. Collector applications compatible

The STM32CubeWBA Health Thermometer Sensor project is compatible with the following collector:

3. STM32WBA P2P Server & P2P Client examples description

3.1. Project directory

The "BLE_p2pServer" & "BLE_p2pClient"applications are available by downloading STM32CubeWBA MCU Package^[5]. LINK TO UPDATE

P2P Server & Client projects directory
File:Connectivity WBA P2Ps dir.png

3.2. Project description

3.2.1. Structure

Software project structure with the most important parts:

P2P Server / Client project structure

Main applicative part files

Bluetooth^® LE Stack API Interface

Services management

System commands

Transport Layer Interface

WARNING: Do not modify the files in Middlewares folder

3.2.2. Application initialization

The different steps of the application initialization are described below:

P2P Server project initialization

Initialize the system (HAL, clocks, peripherals)
Infinite loop for run mode

Initialize the BSP, Power Mode, trace, memory manager, NVM
Wait for initialization done

Initialize the Bluetooth^® LE Host Stack

Initialize the Bluetooth^® LE GATT level
Initialize the Bluetooth^® LE GAP level

Reset the number of registered handler

Initialize the context
Manage Heart Rate Service notification

Register Service Handler
Update services and characteristics

P2P Client project initialization

Initialize the system (HAL, clocks, peripherals)
Infinite loop for run mode

Initialize the BSP, Power Mode, trace, memory manager, NVM
Wait for initialization done

Initialize the Bluetooth^® LE Host Stack

Initialize the Bluetooth^® LE GATT level
Initialize the Bluetooth^® LE GAP level

Reset the number of registered handler

Initialize the context
Register Client Handler

3.2.3. GAP and GATT initialization and interaction

and The Bluetooth LE P2P Server application initialization is done within app_ble.c

Initialize the BLE stack - initialize the device as peripheral - configure and start advertising: ADV parameters, local name, UUID - APP_BLE_init()
Call the services controller initialization SVCCTL_Init() - svc_ctl.c
Manage the GAP event - SVCCTL_App_Notification() - svc_ctl.c
- HCI_LE_CONNECTION_COMPLETE - provides information of the connection interval, slave latency, supervision timeout
- HCI_LE_CONNECTION_UPDATE_COMPLETE- provides the new information of the connection
- HCI_DISCONNECTION_COMPLETE - informs the application about the link disconnection and the reason

The Services management is done by the service controller, svc_ctl.c

Initialize the number of registered handler - SVCCTL_Init()
Manage events - SVCCTL_UserEvtRx()- from the BLE Host Stack and redirect them to the gap event handler - SVCCTL_App_Notification()

The application level of the P2P Server is done with p2p_server_app.c:

Initialization of the services:
- P2P Server Service - P2P_SERVER_Init() - p2p_server.c
Initialization of the context of the application
Receive notification from the P2P Server Service - P2P_SERVER_Notification()
When P2P_SERVER_LED_C_WRITE_NO_RESP_EVT event is received from the P2P Client, the blue LED is toggled.
P2P_SERVER_Switch_c_SendNotification() function is called on Button 1 press, to notify the P2P Client:
- P2P_SERVER_UpdateValue() is called with the notification data - p2p_server.c

The Custom P2P Server Service p2p_server.c manages the specification of the service:

Service Init - P2P_SERVER_Init()
- Register P2P Server Event Handle to Service Controller - SVCCTL_RegisterSvcHandler();
- Initialize Service UUID – add P2P Server service as Primary services
  - Initialize LED_C characteristic
  - Initialize SWITCH_C characteristic
Manage the GATT event from BLE Stack - P2P_SERVER_EventHandler()
- ACI_GATT_ATTRIBUTE_MODIFIED_VSEVT_CODE
  - Reception of an attribute modification - LED C Value : ON or OFF Indication
    - Notify application of the Measurement Notification - P2P_SERVER_Notification(P2P_SERVER_LED_C_WRITE_NO_RESP_EVT)

P2P Server software module interaction

and The Bluetooth LE P2P Client application initialization is done within app_ble.c

Initialize the BLE stack - initialize the device as peripheral - configure and start advertising: ADV parameters, local name, UUID - APP_BLE_init()
Call the services controller initialization SVCCTL_Init() - svc_ctl.c
Manage the GAP event - SVCCTL_App_Notification() - svc_ctl.c
- HCI_LE_CONNECTION_COMPLETE - provides information of the connection interval, slave latency, supervision timeout
- HCI_LE_CONNECTION_UPDATE_COMPLETE- provides the new information of the connection
- HCI_DISCONNECTION_COMPLETE - informs the application about the link disconnection and the reason

The Services management is done by the service controller, svc_ctl.c

Initialize the number of registered handler - SVCCTL_Init()
Manage events - SVCCTL_UserEvtRx()- from the BLE Host Stack and redirect them to the gap event handler - SVCCTL_App_Notification()

The application level of the P2P Client is done with gatt_client_app.c:

Initialization of the application context
- Register Event Handler to BLE Controller - SVCCTL_RegisterCltHandler();
- Initialize LED data level and selection
Manage the GATT event from BLE Stack - gatt_parse_notification()
- ACI_GATT_NOTIFICATION_VSEVT_CODE
  - When the notification event is received from the P2P Server, the blue LED is toggled - gatt_Notification()
Write characteristic to P2P Server (LED toggling) - P2Pclient_write_char() - by pressing Button 1 while connected.

P2P Client software module interaction

3.3. Build and install

Follow the steps described in Bluetooth^® LE Build and Install Application page, applying them for STM32WBA BLE_p2pServer and BLE_p2pClient projects

3.4. How to use

Once the BLE P2P Server application is installed on the STM32WBA platform, launch ST BLE ToolBox smartphone application.

Then, scan and connect the device called p2pS_XX (where XX is replaced by the last byte of the BD address) to the application.
Once the Bluetooth® LE connection is established and the notification enabled by the smartphone (by clicking on P2P Server icon):

LED_C value can be modified by clicking on the LED button on smartphone interface, the blue LED of the Nucleo board is switched On/Off accordingly.
Pressing SW1 button on the board while connected send a SWITCH_C notification to the smartphone and the switch level is updated on the smartphone interface.

3.5. UART debug trace

Thanks to the debug log via UART interface LINK TO UPDATE?, it is possible to trace the application project.

To enable the traces within the project, enable them within app_conf.h as described below:

/**
 * Enable or Disable traces in application
 */
#define CFG_DEBUG_APP_TRACE         (1)

P2P Server - Initialization phase

Connected Phase and LED On notification

==>> Start Ble_Hci_Gap_Gatt_Init function
  Success: hci_reset command
  Success: aci_hal_write_config_data command - CONFIG_DATA_PUBADDR_OFFSET
  Public Bluetooth Address: 00:80:e1:2a:7c:ea
  Success: aci_hal_write_config_data command - CONFIG_DATA_IR_OFFSET
  Success: aci_hal_write_config_data command - CONFIG_DATA_ER_OFFSET
  Success: aci_hal_set_tx_power_level command
  Success: aci_gatt_init command
  Success: aci_gap_init command
  Success: aci_gatt_update_char_value - Device Name
  Success: aci_gatt_update_char_value - Appearance
  Success: hci_le_set_default_phy command
  Success: aci_gap_set_io_capability command
  Success: aci_gap_set_authentication_requirement command
  Success: aci_gap_configure_whitelist command
==>> End Ble_Hci_Gap_Gatt_Init function

Services and Characteristics creation
  Success: aci_gatt_add_service command: P2P_Server
  Success: aci_gatt_add_char command   : LED_C
  Success: aci_gatt_add_char command   : SWITCH_C
End of Services and Characteristics creation

  Success: aci_hal_set_radio_activity_mask command
==>> aci_gap_set_discoverable - Success
==>> Success: Start Advertising

>>== HCI_LE_CONNECTION_COMPLETE_SUBEVT_CODE - Connection handle: 0x0001
     - Connection established with @:7d:64:80:ff:2e:4f
     - Connection Interval:   48.75 ms
     - Connection latency:    0
     - Supervision Timeout: 5000 ms
>>== HCI_LE_CONNECTION_UPDATE_COMPLETE_SUBEVT_CODE
     - Connection Interval:   7.50 ms
     - Connection latency:    0
     - Supervision Timeout:   5000 ms
>>== HCI_LE_CONNECTION_UPDATE_COMPLETE_SUBEVT_CODE
     - Connection Interval:   48.75 ms
     - Connection latency:    0
     - Supervision Timeout:   5000 ms
-- P2P APPLICATION SERVER : NOTIFICATION ENABLED

-- GATT : LED CONFIGURATION RECEIVED
-- P2P APPLICATION SERVER : LED1 ON

4. References

[1] STM32CubeWBA MCU Package

[Stm32CubeIDE-2] STM32CubeIDE

[Stm32CubeProg-3] STM32CubeProgrammer software

[Nucleo_package-4] NUCLEO-WBA5 package

[STM32CubeWB-Package-5] STM32CubeWB MCU Package

[1]

[2]

[3]

[4]

[5]

STM32WBA Bluetooth® LE – Peer 2 Peer Applications