bleLLDataChannelPDUDecode

Decode Bluetooth LE LL data channel PDU

Syntax

[status,cfgLLData,LLPayload] = bleLLDataChannelPDUDecode(dataLLPDU,crcInit)

[status,cfgLLData,LLPayload] = bleLLDataChannelPDUDecode(dataLLPDU,crcInit,inputFormat)

Description

[status,cfgLLData,LLPayload] = bleLLDataChannelPDUDecode(dataLLPDU,crcInit) decodes a Bluetooth^® low energy (LE) link layer (LL) data channel protocol data unit (PDU), dataLLPDU, returning the decoding status, status, the Bluetooth LE LL data channel PDU configuration object, cfgLLData, and the upper-layer payload, LLPayload. The CRCinit denotes the initialization value of cyclic redundancy check (CRC).

[status,cfgLLData,LLPayload] = bleLLDataChannelPDUDecode(dataLLPDU,crcInit,inputFormat) additionally sets the format of the Bluetooth LE LL data channel PDU.

Examples

Decode Bluetooth LE LL Data Channel PDU Given in Bits

Create a default Bluetooth LE LL data channel PDU configuration object.

cfgLLData = bleLLDataChannelPDUConfig

cfgLLData = 
  bleLLDataChannelPDUConfig with properties:

                 LLID: 'Data (continuation fragment/empty)'
                 NESN: 0
       SequenceNumber: 0
             MoreData: 0
    CRCInitialization: '012345'

Set the LLID value to 'start fragment/complete'. Initialize the cyclic redundancy check (CRC) value to 'ED321C'.

cfgLLData.LLID = 'Data (start fragment/complete)';
cfgLLData.CRCInitialization = 'ED321C';
crcInit = 'ED321C';

Generate a Bluetooth LE LL data channel PDU with upper-layer payload in hexadecimal octets.

dataLLPDU = bleLLDataChannelPDU(cfgLLData,'030004000A0100');

Decode the generated Bluetooth LE LL data channel PDU. The returned status indicates decoding is successful.

[status,cfgLLData,llPayload] = bleLLDataChannelPDUDecode(dataLLPDU,crcInit)

status = 
  blePacketDecodeStatus enumeration

    Success

cfgLLData = 
  bleLLDataChannelPDUConfig with properties:

                 LLID: 'Data (start fragment/complete)'
                 NESN: 0
       SequenceNumber: 0
             MoreData: 0
    CRCInitialization: 'ED321C'

llPayload = 7×2 char array
    '03'
    '00'
    '04'
    '00'
    '0A'
    '01'
    '00'

Decode Bluetooth LE LL Data Channel PDU Given in Octets

Specify a sample Bluetooth LE LL data channel PDU in octets.

dataLLPDU = '030C00010000060000000A000000FCD2A6';

Initialize the CRC value.

crcInit = 'ED323C';

Decode the specified Bluetooth LE LL data channel PDU by specifying the 'inputFormat' to 'octets'. The specified PDU is a control PDU. The returned status indicates decoding is successful. You can see the decoded configuration of the specified PDU in the 'ControlConfig' property of 'cfgLLData'.

[status,cfgLLData,llPayload] = bleLLDataChannelPDUDecode(dataLLPDU,crcInit, ...
    'InputFormat','octets')

status = 
  blePacketDecodeStatus enumeration

    Success

cfgLLData = 
  bleLLDataChannelPDUConfig with properties:

                 LLID: 'Control'
                 NESN: 0
       SequenceNumber: 0
             MoreData: 0
    CRCInitialization: 'ED323C'
        ControlConfig: [1×1 bleLLControlPDUConfig]

llPayload =

  1×0 empty char array

Decode Corrupted Bluetooth LE LL Data Channel PDU

Specify a Bluetooth LE LL data channel PDU containing corrupted data values. Initialize the CRC value.

dataLLPDU = '040C00010000060000000A00';
crcInit = 'CD3234';

Decode the specified Bluetooth LE LL data channel PDU. The returned status indicates that the decoding failed due to the corrupted Bluetooth LE LL data channel PDU. If the decoding fails, the reason is indicated and the object displays no properties.

[status,cfgLLData,llPayload] = bleLLDataChannelPDUDecode(dataLLPDU,crcInit, ...
    'InputFormat','octets')

status = 
  blePacketDecodeStatus enumeration

    CRCFailed

cfgLLData = 
  bleLLDataChannelPDUConfig with properties:

llPayload =

  1×0 empty char array

Input Arguments

dataLLPDU — Bluetooth LE LL data channel PDU

character vector | string scalar | numeric vector | character array | binary vector

Bluetooth LE LL data channel PDU, specified as one of these values:

• Character vector — This vector represents octets in hexadecimal format.

• String scalar — This scalar represents octets in hexadecimal format.

• Numeric vector of elements in the range [0,255] — This vector represents octets in decimal format.

• n-by-2 character array — Each row represents an octet in hexadecimal format. n represents total number of rows.

• Binary vector — This vector represents Bluetooth LE LL data channel PDU bits.

Data Types: char | string | double

crcInit — CRC initialization value

character vector | string scalar

CRC initialization value, specified as a 6-element character vector or a string scalar representing 3-octet hexadecimal value.

Data Types: char | string

inputFormat — Bluetooth LE LL data channel PDU format

'bits' (default) | 'octets'

Bluetooth LE LL data channel PDU format, specified as 'bits' or 'octets'. When specified as 'bits', this input is a binary vector. When specified as 'octets', this input is a numeric vector representing octets in decimal format or a character array or a string scalar representing octets in hexadecimal format.

Data Types: char | string | double

Output Arguments

status — Bluetooth LE LL data channel PDU decoding status

nonpositive integer

Bluetooth LE LL data channel PDU decoding status, returned as a nonpositive number of type blePacketDecodeStatus. This value represents the result of a Bluetooth LE LL data channel PDU decoding. Each value of this output corresponds to a member of the blePacketDecodeStatus enumeration class, which indicates the packet decoding status as shown in this table.

Value of status	Member of Enumeration Class	Decoding Status
0	Success	Packet decoding succeeded
-1	CRCFailed	Link Layer PDU is corrupted
–2	LLPDULengthMismatch	Length field does not match with actual PDU length
–3	InvalidLLPeripheralLatency	Invalid Peripheral latency
–4	InvalidLLConnectionTimeout	Invalid connection timeout
–5	InvalidLLWindowSize	Invalid window size
–6	InvalidLLWindowOffset	Invalid window offset
–7	InvalidLLConnectionInterval	Invalid connection interval
–8	InvalidLLChannelMap	Invalid channel map
-101	IncompleteLLDataChannelPDU	Insufficient octets in data channel PDU
-102	InvalidLLID	Invalid LLID
-103	UnsupportedLLOpCode	Unsupported opcode
-104	InvalidLLErrorCode	Invalid error code
-105	InvalidBluetoothVersion	Invalid version
-106	ExpectedNonZeroPayload	Nonzero payload expected
-107	MICNotSupported	Payload contains MIC

An enumeration value other than 0 implies failed Bluetooth LE LL data channel PDU decoding. If decoding fails, the cfgLLData argument displays no output.

cfgLLData — Bluetooth LE LL data channel configuration object

bleLLDataChannelPDUConfig object

Bluetooth LE LL data channel configuration object, returned as a bleLLDataChannelPDUConfig object.

LLPayload — Upper-layer payload

array

Upper-layer payload, returned as a character array where each row is the hexadecimal representation of an octet.

References

[1] Bluetooth Technology Website. “Bluetooth Technology Website | The Official Website of Bluetooth Technology.” Accessed November 22, 2021. https://www.bluetooth.com/.

[2] Bluetooth Special Interest Group (SIG). "Bluetooth Core Specification." Version 5.3. https://www.bluetooth.com/.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

• When the CRCInitialization property of the bleLLDataChannelPDUConfig object is set to constant, code generation is possible.

Version History

Introduced in R2019b