Description

This frame type is emitted whenever the Bluetooth scanner detects a legacy advertisement from nearby devices during a GAP scan. This response frame provides valuable information about the detected advertisement including their addresses, advertisement types, signal strengths, and additional data contained within the advertisement payload.

Format

The following table provides the contents of the frame. For details on frame structure, see API frames.

Offset Size Field Name Description

0

8-bit

Start Delimiter

Indicates the start of an API frame.

1

16-bit

Length

Number of bytes between the length and checksum.

3

8-bit

Frame Type

Bluetooth Scan Response - 0xB4

4

48-bit

Address

The BLE MAC address of the received advertisement.

10

8-bit

Address type

Indicates whether the Bluetooth address is a public address or a randomly generated address.

11

8-bit

Advertisement flags

Bit field that indicates advertisement flags:

  • Bit 0: Device is connectable

  • Bit 1-7: Reserved

12

8-bit

RSSI

The received signal strength of the advertisement, in -dBm.

13

8-bit

Reserved

Unused.

14

8-bit

Payload length

Specifies the length of the advertisement payload.

16-n

variable

Payload

The actual data payload of the advertisement which can contain various information elements, manufacturer-specific data, or other relevant details about the advertising device.

EOF

8-bit

Checksum

0xFF minus the 8-bit sum of bytes from offset 3 to this byte (between length and checksum).