RE: Scanning Bluetooth infotainment communication

Edvin — Wed, 31 Jul 2019 09:14:02 GMT

Hello,

No. The nRF5x family doesn't support Classic Bluetooth.

RE: Scanning Bluetooth infotainment communication

Tue, 30 Jul 2019 19:06:17 GMT

Thank you @Edvin for the prompt reply. Infotainment systems do use Classic Bluetooth. Isn't nRF5x family dual mode, doesn't it support Classic Bluetooth?

RE: Scanning Bluetooth infotainment communication

Edvin — Tue, 30 Jul 2019 13:08:26 GMT

Hello,

infotainment systems are often using Classic Bluetooth, and not Bluetooth Low Energy (BLE), if I am not mistaken, but I am not sure. At least they use Classic bluetooth to transfer audio, as this is not supported in BLE.

It may be that they use BLE in the connection process, and to send simple commands (play/pause, next song, and so on).

However, if it uses BLE, it is possible to scan for BLE advertising packets using the nRF52840 DK, and the events that trigger whenever it receives a packet will contain the received signal strength. It will also. Using the BLE stack for the DKs, you can scan for advertisement packets, but not the connection requests, so you will only be able to find one side (I guess that would be the car).

It is possible to use the nRF Sniffer to capture the entire communication (as long as it is BLE), but as soon as they enter a connection which I assume is encrypted, you will not be able to decrypt the messages unless you have access to the keys.

Another thing that is worth mentioning is that mobile phones use a private resolvable address, so it periodically changes it's BLE address, making it impossible for devices that are not bonded (stored encryption keys for future use) to the phone to see that it is the same device as it was the last time. The infotainment system may use this kind of private resolvable address as well to avoid unwanted tracking of the car.