CC2564: VS_Set_Bluetooth_Address v. GAP_Query_Local_BD_ADDR functions

Chris Yorkey

Part Number: CC2564

BT Family & Friends,

Our customer is asking the following: We are trying to use the vendor specific function VS_Set_Bluetooth_Address to set the board MAC address. However, even though the return value from the function indicates that the function succeeded, when we check the board mac address using the GAP_Query_Local_BD_ADDR function, the MAC address is not changed. What could be the problem? Thanks.

We've asked to verify with a Sniffer app on mobile device and indeed the MAC address is not changed. There are also other function parameters to pay attention to such as frequency, etc but these should not impact whether or not the MAC address is indeed written or read to. Thoughts?

TY,

over 7 years ago

0 Hari Nagalla over 7 years ago

TI__Mastermind 27090 points

Humm.. Are you using the, "HCI_VS_Write_BD_Addr'? It should work.. Since, it is not persistent, you need to issue this command each time the controller is booted..

processors.wiki.ti.com/.../CC256x_VS_HCI_Commands

0 Chris Yorkey over 7 years ago in reply to Hari Nagalla

TI__Genius 16330 points

Thank you for the info Hari.
Per our customer, HCI_VS_Write_BD_Addr seems to be a protocol command being used. They have checked the implementation of the VS_Set_Bluetooth_Address command. It apparently uses the HCI_Send_Raw_Command command to send a command packet to the controller. The command type in that packet is set to 0xFC06, which is the code for the HCI_VS_Write_BD_Addr command.

Please let me know if this is right and/or if you have further recommendations or comments.

TY,
CY

0 Hari Nagalla over 7 years ago in reply to Chris Yorkey

TI__Mastermind 27090 points

When are they issuing this command to change BD address? What are the sequence of operations?
Which host and BT stack are they using?

Thanks

0 Chris Yorkey over 7 years ago in reply to Hari Nagalla

TI__Genius 16330 points

Hari,

The hardware they are using are the TM4C129X Devboard + CC2564MODAEM (REV1.0).

The software they are using is the TivaWare_C_Series_2.1.4.178+CC256X M4 Blutopia SDK (V1.2 R2).

The sample project their work is based on is the SPPLEDemo project.

They are trying to change the MAC address after the hardware and the Bluetooth stack initialization.

The device is essentially not doing anything yet in terms of other functionality. No advertising and no scanning yet at that point.

Your comments indeed welcomed.

TY,
CY

0 Hari Nagalla over 7 years ago in reply to Chris Yorkey

TI__Mastermind 27090 points

I suspect, the encoding of the command to change BD address is getting messed up from the application. Can, you take FW logs to check, how the command is received at the controller?

processors.wiki.ti.com/.../CC256x_Logger_User_Guide

Thanks

0 Chris Yorkey over 7 years ago in reply to Hari Nagalla

TI__Genius 16330 points

Hello Hari,

Thank you so much. The customer checked out the original SPPLEDemo project and tried those two commands. After the VS_Set_Bluetooth_Address command, they even added a long enough delay to make sure the command has enough time to write the address.

The findings are consistent:

-The VS_Set_Bluetooth_Address command does set a temporary MAC address that is used to connect to other BLE devices.

-The GAP_Query_Local_BD_ADDR command returns a fixed MAC address that could be different from the temporary MAC address.

Maybe it is designed that way so the permanent MAC address won’t get lost. We are assuming that is the case.

Thanks again!

-Chris

Bluetooth®︎

Bluetooth forum

CC2564: VS_Set_Bluetooth_Address v. GAP_Query_Local_BD_ADDR functions