GenFSK for BLE advertisement and use of Coded PHY (KW38)

[no6524]

I know GenFSK can be used to sent Bluetooth advertisement on a KW3x microcontroller.

I have done it on a KW36 on a previous project and am interesting in doing the same on a KW38 (with a Freedom board).

I have tried to run the genfsk beacon example but am not able to see advertisement packets from my smartphone. Could you help me setting up this example to see BLE advertisement ?

Once this is done, I would like to use the same mechanism but to send LE Coded PHY advertisement for Long Range capability (either S=2 or S=8). Looking at the BLE specification for Coded PHY it should be possible to send the 3 primary channel advertisements packets and the second channel advertisement packet required for extended advertisement.

Regards.

[no6524]

Hi,

Sorry for the late reply, I was on another project.

I tried the hs_beacon_bm example with gAppDefaultDataRate set to either gGenfskDR1Mbps_c or gGenfskDR2Mbps_c and in both case after flashing and pressing the SW2 button I was unable to see any advertisement on my smartphone.

The smartphone (Huawei P30) is a BLE 5 capable smartphone that supports both 2MBps and Coded PHY.

The ble_w_uart_gfsk_bm example does work : I see the advertisement on my smartphone, but I really want to have the GenFSK example running.

Also : is it possible to use LE Coded PHY with GenFSK example ? s=2 or s=8 ?

Or is Coded PHY handled in software inside the BLE stack ?

[mario_castaneda]

Hi @no6524,

I reproduced the issue, and I am using the P30 Huawei, and also with some android devices.

The iPhone detects this adv and the sniffer that I have.

I am checking this, I will get back to you as soon as possible.

Regards,

Mario

[mario_castaneda]

Hi @no6524,

In the Bluetooth LE 5.0 specification, Vol 6 part B, we have this table, please see the image attached.

Thus, the 2M PHY is not allowed for simple BLE beaconing (ADV_NONCONN_IND).

If the customer wants to test the 2Mbps BLE beacon, I would recommend him to refer to the BLE Beacon demo example instead of the genFSK example, because the BLE Beacon example demonstrates the Extended Advertising which supports the 2M PHY.

Regards,

Mario

[no6524]

Thanks for the response.

I know that both 2M PHY advertisement packet and Coded PHY advertisement packets require the use of extended advertisement.

I am planning to implement primary and secondary advertisement packets for extended advertisement (for Coded PHY).

Before I go into implementing the timing requirements for the primary and secondary adv packets, I am interested in how to generate the Coded PHY packet.

I see in the KW38 reference manual that the preamble can be configured to a specific Byte pattern. I guess for Coded PHY, I should set this (GEN_PREAMBLE) to 0x3C.

Can you confirm ?

Also, regarding the FEC encoding (and pattern matching) : is it something that can be done in hardware or in software ? I am looking to implement it is software but for that I would need to use a bigger access address (32 Bytes instead of 4). Is this possible ?

[mario_castaneda]

Hi @no6524,

I strongly recommend using the BLE Beacon example demonstrates the Extended Advertising which supports the 2M PHY. and also the coded PHY.

Did you run t his example?

Regards,

Mario

[mario_castaneda]

Hi @no6524,

I hope you are doing great.

What is the app or the device that you are using as a scanner?

I tested by my side, I am using an android device, be sure that your device supports the 2M PHY, otherwise you have to change to the 1M PHY.

Also, I used the sniffer KW41, and I am seeing the packets over the air, only using the 1M PHY.

Could you please text the next example?

\SDK_2_6_12_FRDM-KW38\boards\frdmkw38\wireless_examples\hybrid\ble_w_uart_gfsk

Please let me know your findings.

Regards,

Mario