SWRA715 December   2021 CC2642R , CC2652R

 

  1.   Trademarks
  2. 1Introduction
  3. 2Bluetooth Low Energy Introduction
  4. 3HOGP Introduction
    1. 3.1 HID Roles
    2. 3.2 HID Host
    3. 3.3 HID Device
  5. 4Project Description and Walkthrough
    1. 4.1  General Project Discussion
    2. 4.2  Report Map Discussion
    3. 4.3  Hid_input struct/union Discussion
    4. 4.4  Mouse Operation
    5. 4.5  Keyboard Operation
    6. 4.6  Consumer Report Operation
    7. 4.7  Connection Interval
    8. 4.8  Notification System
    9. 4.9  PDU Size and Number of PDUs per Connection Event
    10. 4.10 Notification Payload Discussion
      1. 4.10.1 Mouse Notification
      2. 4.10.2 Keyboard Notification
      3. 4.10.3 Consumer Report Notification
    11. 4.11 Throughput Discussion
    12. 4.12 Overall Block Diagrams
  6. 5Demo Usage
    1. 5.1 Hardware/Software Used
    2. 5.2 Mouse Demo Usage
    3. 5.3 Keyboard and Consumer Report Demo Usage
  7. 6Summary

4.9 PDU Size and Number of PDUs per Connection Event

The PDU size and PDU amount have a direct impact on notifications. The max size of PDUs is set to 69 bytes in the project by default. This is the minimum size that should be used for this project because this is the minimum size required by the LE Secured Connections feature. The number of PDUs per connection event has a more direct impact on the project. The mouse demo portion of the project constantly enqueues notifications. If a project is enqueuing notifications at a rapid pace, then a large number of PDUs is required per connection event in order to keep up with the stream of notifications. If the amount of PDUs is set lower than the notification stream requires, then data loss may occur. The project has the PDU amount per connection event set to the maximum of 255 PDUs. This setting should be minimized in a final implementation of this project to a value that offers minimal data loss while also offering minimal heap consumption. For additional information on PDUs and their impact, see the Link Layer (LL) chapter of the SDK User’s Guide.