Inquiry Regarding Bluetooth PHY Mode Usage on Device

[Raz_k]

Hello,

I am currently investigating the Bluetooth Low Energy (BLE) PHY modes utilized by our nRF52840 device, which lacks documentation and was programmed by an external developer.

Our objective is to report the specific PHY modes being used for regulatory compliance purposes, especially considering that each PHY mode may incur additional fees.

Upon reviewing the device's code, I noted that no explicit definition of the BLE PHY type was found. Debug print statements revealed that the value 0 (indicating BLE_GAP_PHY_AUTO) was printed, suggesting that the Bluetooth stack dynamically selects the PHY mode during runtime, with all three options (LE 1M, LE 2M, LE Coded) being potential candidates.

I have the following questions:

1. Can you confirm if the Bluetooth stack indeed dynamically selects the PHY mode during runtime as described?
2. How can I determine definitively which PHY mode(s) is actively being used or excluded?
3. Is there a method or tool available that allows us to monitor and observe the actively used PHY mode in real-time during device operation?

Thanks a lot,

Raz

[Amanda Hsieh]

Hi,

Can you confirm if the Bluetooth stack indeed dynamically selects the PHY mode during runtime as described?

Yes, if it uses the automatic PHY selection. Refer sd_ble_gap_phy_update for more information.

How can I determine definitively which PHY mode(s) is actively being used or excluded?

From: ATT_MTU Throughput Example

Is there a method or tool available that allows us to monitor and observe the actively used PHY mode in real-time during device operation?

You can check tx_phy and rx_phy in runtime. 

Regards,
Amanda H.