4.2.1.3 Protocol Exchange

1. BLE Sensor Data in Advertising Beacon:

• Advertisement Data:

  • Service UUID: 16-bit Service UUID, 0xFEDA is purchased by Microchip from Bluetooth SIG.

  • BLE Sensor data: 0x40+Light ON/Off status (1 Byte)+ 0x41+Temperature data (2 bytes)

• Scan Response Data:

  • The device name is part of the scan response. Device name is set as "BLE_SENSOR_XXXX” (XXXX means the last two bytes of the device address).

2. Transparent Profile and Service (TRP/TRS):

Transparent Profile and Service (TRP/TRS) is the proprietary BLE service by microchip to establish data and control channel between BLE Central (Phone) and Peripheral (device).

• Transparent Profile (TRP) enables higher layer application to control and allow data exchange between TRP Client and Server devices

• Transparent Service (TRS) includes both Ctrl and Data Pipes which are custom 128-bit GATT characteristics.

  • The Transparent Server shall be a GATT Server

  • The Transparent Client shall be a GATT Client

    Definition of Transparent Service and Characteristics UUID's

    Characteristic Name	UUID	Properties
    TRS Service	49535343-FE7D-4AE5-8FA9-9FAFD205E455
    TRS TxD- Tx Data to Client role (Data pipe)	49535343-1E4D-4BD9-BA61-23C647249616	Notify, Write
    TRS TxD - Client Characteristic Configuration Descriptor		Read, Write
    TRS RxD- Rx Data from Client role (Data pipe)	49535343-8841-43F4-A8D4-ECBE34729BB3	Write, Write without response
    TRS Ctrl Pt - Command and Response (Ctrl pipe)	49535343-4C8A-39B3-2F49-511CFF073B7E	Notify, Write, Write without response
    TRS Ctrl Pt - Client Characteristic Configuration descriptor		Read, Write

3. BLE Sensor Application over Transparent Service Control Point (TRS Ctrl Pt):

BLE Sensor application uses TRS Control Point Characteristic of TRPS profile to exchange data between mobile phone and device.

The BLE Sensor application follows the following protocol format on TRS control point characteristic.

The description of each element is as below:

- The Opcode: (0x8A) is fixed 1 byte in size and related to BLE Sensor/Control commands.
- Length: 1 byte in size (size of Sensor/Control ID + size of Payload)
- The Sensor/Control ID: 1 byte in size. It could be divided into Control request, Control response, Sensor notify data described in detail in following sections.
- The Sensor/control data and payload size depends on the Sensor/Control ID as listed in the below table.

BLE Sensor Application Control and Sensor Command/Response

Control Command Request and Response

The Control command request is used by mobile app to send the command to device. The control request channel is opened only after Client Characteristic Configuration Descriptor of TRS Ctrl Pt Characteristic notification is enabled; it is closed when such notification is disabled.

The format of Control command is an 8bit Opcode, an 8bit request ID followed by optional control payload.

Format of Control Command

The control response is used by the device to send feedback to mobile app. The format of Response is an 8bit Opcode, an 8bit response ID and response status followed by optional Response payload.

Format of Control Response Data

Status code 0x00 means successful execution of control command. Any status code other than 0x00 means error code, as shown in below Table. An error status does not have optional control Response payload.

Definition of Status Code

Sensor Notify Data

The Sensor data is sent to mobile app periodically by WBZ351 device. The sensor data channel is opened only after Client Characteristic Configuration Descriptor of TRS Ctrl Pt notification is enabled; it is closed when such notification is disabled.

The format of sensor data is an 8bit Opcode, an 8bit Sensor ID followed by sensor data payload.

Format of Sensor Data