CC2652R: GATT Profile Characteristic Variable Size

Mohsan Naeem

Part Number: CC2652R

Hi ..

Hope you enjoying best of your health ! I am using "SimpleGATTProfile " characteristic 1 with Fixed Length of 27 byte .I have msg of different length vary from 4 byte to 24 byte written on same charateristic 1 of simple Gatt profile .In Every Case Bluetooth Transmit same 27 byte

Could I configure BLE to send only size of 4 byte in case of 4 byte msg and 24 byte in case of 24 byte msg??

If yes .What will be the basic Procedure to do it ?

over 5 years ago

0 Ammar N over 5 years ago

TI__Mastermind 25810 points

Hey Mohsan,

I've assigned an expert to comment.

0 Jenny T over 5 years ago

TI__Expert 4435 points

Hi Mohsan,

Are you using SimpleCentral to write to the characteristic? If so, you can set the write length when using a GATT write API for instance GATT_WriteCharValue(). SimpleCentral_doGattWrite() in simple_central.c of the Simple Central example shows how to do this.

A write request is passed to GATT_WriteCharValue() where the specific request length of the value can be specified. Please reference the TI BLE5-Stack API Documentation for information on this write request.

Best Regards,

Jenny

0 Mohsan Naeem over 5 years ago in reply to Jenny T

Prodigy 130 points

Hy Jenny .. Thanks for you remarkable comment .

It partially resolved my issue about variable length

.Here i am facing issue When i increase the PDU to 255 and characteristic length from 100 to 251.I just recieved First 27 Byte correctly.

After 27 byte i just recieve some garbage value but i recieve exact length..

What could be the possible solution

0 Mohsan Naeem over 5 years ago in reply to Jenny T

Prodigy 130 points

Hy Jenny .. Thanks for your remarkable comment .

It partially resolved my issue about variable length

.Here i am facing issue When i increase the PDU to 255 and characteristic length from 100 to 251.I just received First 27 Byte correctly.

After 27 byte I just receive some garbage value, but I receive exact length..

What could be the possible solution?

0 Evan W over 5 years ago in reply to Mohsan Naeem

TI__Mastermind 41650 points

Mohsan,

Do you have a snifferlog of the behavior you are describing?

Bluetooth®︎

Bluetooth forum

CC2652R: GATT Profile Characteristic Variable Size