CSR8675 Bluetooth Audio - aptX Enabling?

[ssashton]

Hi guys and gals,

I purchased a number of CSR8675 bluetooth audio modules but they will not switch to using the aptX codec. They are stuck using SBC.

I have confirmed it is not a problem with my phone as I can use aptX on other bluetooth receivers. I can see the codec being used in the android developer menu.

Is there some kind of firmware setting that needs to be enabled to activate aptX mode?

Anybody got experience programming these chips?

Thanks!

[ssashton]

Just thought I'd follow up on this. Turns out you need an aptX key loaded in the firmware.

[Buriedcode]

Yes, these are often ROM devices, with external EEPROM for settings.  This means you cannot change the firmware, so if it doesn't have Apt-X enabled in the firmware, you can't use it.

If however, the module has >4MB flash instead of the EEPROM, then it might be possible to change the firmware, but as you found out the Apt-X is licensed, and so requires a key to use it in the IDE.