SWRU271I October   2010  – January 2020 CC2540 , CC2540T , CC2541 , CC2541-Q1 , CC2640R2F

 

  1.   Preface
    1.     Trademarks
    2.     Related Documentation
  2. 1Overview
    1. 1.1 Support Note
    2. 1.2 Introduction
    3. 1.3 Bluetooth Low Energy Protocol Stack Basics
  3. 2The TI Bluetooth Low Energy Software Development Platform
    1. 2.1 Overview
    2. 2.2 Configurations
    3. 2.3 Projects
    4. 2.4 Software Overview
  4. 3The Operating System Abstraction Layer (OSAL)
    1. 3.1 Overview
    2. 3.2 Task Initialization
    3. 3.3 Task Events and Event Processing
    4. 3.4 Heap Manager
    5. 3.5 OSAL Messages
  5. 4The Application and Profiles
    1. 4.1 Overview
    2. 4.2 Project Overview
    3. 4.3 Start-up in main()
    4. 4.4 Application Initialization
    5. 4.5 Event Processing
      1. 4.5.1 Periodic Event
      2. 4.5.2 OSAL Messages
    6. 4.6 Callbacks
    7. 4.7 Complete Attribute Table
    8. 4.8 Additional Sample Projects
  6. 5The Bluetooth Low Energy Protocol Stack
    1. 5.1 Overview
    2. 5.2 Generic Access Profile (GAP)
      1. 5.2.1 Overview
        1. 5.2.1.1 Connection Parameters
        2. 5.2.1.2 Effective Connection Interval
        3. 5.2.1.3 Connection Parameter Considerations
        4. 5.2.1.4 Connection Parameter Update
        5. 5.2.1.5 Connection Termination
      2. 5.2.2 GAP Abstraction
      3. 5.2.3 Configuring the GAP Layer
    3. 5.3 GAPRole Task
      1. 5.3.1 Peripheral Role
      2. 5.3.2 Central Role
    4. 5.4 Gap Bond Manager (GAPBondMgr)
      1. 5.4.1 Overview of Bluetooth Low Energy Security
      2. 5.4.2 Using the GapBondMgr Profile
      3. 5.4.3 GAPBondMgr Examples for Various Security Modes
        1. 5.4.3.1 Pairing Disabled
        2. 5.4.3.2 Just Works Pairing Without Bonding
        3. 5.4.3.3 Just Works Pairing With Bonding Enabled
        4. 5.4.3.4 Authenticated Pairing
        5. 5.4.3.5 Authenticated Pairing With Bonding Enabled
    5. 5.5 Generic Attribute Profile (GATT)
      1. 5.5.1 GATT Characteristics and Attributes
      2. 5.5.2 GATT Services and Profile
      3. 5.5.3 GATT Client Abstraction
        1. 5.5.3.1 Using the GATT Layer Directly
      4. 5.5.4 GATT Server Abstraction
        1. 5.5.4.1 GATTServApp Module
          1. 5.5.4.1.1 Building Up the Attribute Table
        2. 5.5.4.2 Profile Architecture
          1. 5.5.4.2.1 Attribute Table Definition
            1. 5.5.4.2.1.1 Service Declaration
            2. 5.5.4.2.1.2 Characteristic Declaration
            3. 5.5.4.2.1.3 Characteristic Value
            4. 5.5.4.2.1.4 Client Characteristic Configuration
          2. 5.5.4.2.2 Add Service Function
          3. 5.5.4.2.3 Register Application Callback Function
          4. 5.5.4.2.4 Read and Write Callback Functions
            1. 5.5.4.2.4.1 Read Request from A GATT Client
            2. 5.5.4.2.4.2 Write Request From Client
          5. 5.5.4.2.5 Get and Set Functions
    6. 5.6 L2CAP
    7. 5.7 HCI
      1. 5.7.1 HCI Extension Vendor-Specific Commands
      2. 5.7.2 Receiving HCI Extension Events in the Application
    8. 5.8 Library Files
  7. 6Drivers
    1. 6.1  Overview
    2. 6.2  ADC
    3. 6.3  AES
    4. 6.4  LCD
    5. 6.5  LED
    6. 6.6  KEY
    7. 6.7  DMA
    8. 6.8  UART and SPI
    9. 6.9  Other Peripherals
    10. 6.10 Simple NV (SNV)
  8. 7Creating a Custom Bluetooth Low Energy Application
    1. 7.1 Overview
    2. 7.2 Configuring the Bluetooth Low Energy Stack
    3. 7.3 Define Bluetooth Low Energy Behavior
    4. 7.4 Define Application Tasks
    5. 7.5 Configure Hardware Peripherals
    6. 7.6 Configuring Parameters for Custom Hardware
      1. 7.6.1 Board File
      2. 7.6.2 Adjusting for 32-MHz Crystal Stabilization Time
      3. 7.6.3 Setting the Sleep Clock Accuracy
    7. 7.7 Software Considerations
      1. 7.7.1 Memory Management for GATT Notifications and Indications
      2. 7.7.2 Limit Application Processing During Bluetooth Low Energy Activity
      3. 7.7.3 Global Interrupts
  9. 8Development and Debugging
    1. 8.1 Overview
    2. 8.2 IAR Overview
    3. 8.3 Using IAR Embedded Workbench
      1. 8.3.1 Open an Existing Project
      2. 8.3.2 Project Options, Configurations, and Defined Symbols
      3. 8.3.3 Building and Debugging a Project
      4. 8.3.4 Linker Map File
  10. 9General Information
    1. 9.1 Overview
    2. 9.2 Porting From BLE-Stack 1.5.0 to 1.5.1
    3. 9.3 Porting From BLE-Stack 1.4.2 to 1.5.0
    4. 9.4 Porting From Earlier BLE-Stack Versions
      1. 9.4.1 Porting BLEv1.4.1 Projects to BLEv1.4.2
      2. 9.4.2 Porting BLEv1.4.0 Projects to BLEv1.4.1
        1. 9.4.2.1 Project Porting Directions
        2. 9.4.2.2 API Changes
        3. 9.4.2.3 Typedef Changes
        4. 9.4.2.4 Structure Changes
          1. 9.4.2.4.1 Array Elements Changed to Pointers
          2. 9.4.2.4.2 Additional Fields in Key Distribution Strucutre
        5. 9.4.2.5 Default Value of HAL Components
        6. 9.4.2.6 Allocating Memory for Over-the-Air Messages
        7. 9.4.2.7 Allocation of Client Characteristic Configuration Table
      3. 9.4.3 Porting BLEv1.3.2 Projects to BLEv1.4.0
      4. 9.4.4 Porting BLEv1.2 Projects to BLEv1.3
      5. 9.4.5 Porting From CC2540 to CC2541 Project
    5. 9.5 Release Notes History
    6. 9.6 Document History
  11.   A GAP API
    1.     A.1 Commands
    2.     A.2 Configurable Parameters
    3.     A.3 Events
  12.   B GAPRole Peripheral Role API
    1.     B.1 Commands
    2.     B.2 Configurable Parameters
    3.     B.3 Callbacks
      1.      B.3.1 State Change Callback (pfnStateChange)
      2.      B.3.2 RSSI Callback (pfnRssiRead)
  13.   C GAPRole Central Role API
    1.     C.1 Commands
    2.     C.2 Configurable Parameters
    3.     C.3 Callbacks
      1.      C.3.1 RSSI Callback (rssiCB)
      2.      C.3.2 Central Event Callback (eventCB)
  14.   D GATT/ATT API
    1.     D.1 Overview
    2.     D.2 Server Commands
    3.     D.3 Client Commands
    4.     D.4 Return Values
    5.     D.5 Events
    6.     D.6 GATT Commands and Corresponding ATT Events
    7.     D.7 ATT_ERROR_RSP Error Codes
  15.   E GATTServApp API
    1.     E.1 Overview
    2.     E.2 Commands
  16.   F GAPBondMgr API
    1.     F.1 Overview
    2.     F.2 Commands
    3.     F.3 Configurable Parameters
    4.     F.4 Callbacks
      1.      F.4.1 Passcode Callback (passcodeCB)
      2.      F.4.2 Pairing State Callback (pairStateCB)
  17.   G HCI Extension API
    1.     G.1 Overview
    2.     G.2 Commands
    3.     G.3 Host Error Codes
  18.   Revision History

3.3 Task Events and Event Processing

After the OSAL initializes, it runs in an infinite loop checking for task events. You can find this loop in the osal_start_system() function in the OSAL.c file. Task events are stored as unique bits in a 16-bit variable where each bit corresponds to a unique event. The application determines the definition and use of these event flags. Figure 3-1 shows a flow diagram of the OSAL processing scheme.

figure_05_swru271.gifFigure 3-1 OSAL Task Loop

If the SimpleBLEPeripheral application defines a flag in simpleBLEPeripheral.h: SBP_START_DEVICE_EVT (0x0001) indicating the initial device start is complete, the application processing begins. The application cannot define one reserved flag value (0x8000). This value corresponds to the event SYS_EVENT_MSG for messaging between tasks. For more information, see Section 3.5.

When the OSAL detects an event set for a task, it calls the event processing routine of that task to process the event. The task layer must add its own event processing routine to the table formed by the array of function pointers called tasksArr (defined in OSAL_SimpleBLEPeripheral.c for the SimpleBLEPeripheral example project). The order of the event processing routines in tasksArr is the same as the order of task IDs in the osalInitTasks() function. Maintaining this task order is required for the correct software layer to process events.

In the SimpleBLEPeripheral application, the event processing function is called SimpleBLEPeripheral_ProcessEvent() to handle all active events associated with the task. After processing, the events must be cleared to prevent duplicate processing of the same event. The SimpleBLEPeripheral_ProcessEvent() application function shows that after the START_DEVICE_EVT event occurs it returns the 16-bit events variable with the SBP_START_DEVICE_EVT flag cleared.

code_sec3_4__swru271.gif

Any layer of the software can set an OSAL event for any layer. Use the osal_set_event() function (prototype in OSAL.h) to immediately schedule a new OSAL event. With this function, you specify the task ID (of the task that will process the event) and the event flag as parameters.

An alternate method to set an OSAL event for any layer is to use the osal_start_timerEx() function (prototype in OSAL_Timers.h). This function operates similarly to the osal_set_event() function. You select the task ID of the task that will process the event and the event flag as parameters. The osal_start_timerEx() function has a third parameter that you must use to input a time-out value in milliseconds. This timeout parameter causes the OSAL to set a timer and set the specified event when the timer expires.