cannot create bt0 in raspberry pi3

[lucidlynx]

Hello all,

Environment:

• Rpi with Raspbian Stretch (Release 9.8)
• Kernel 4.14.8-v7+
• Architecture armv7l

I have followed the below links to build BLE 6LoWPAN environment on my Rpi3

• https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.sdk5.v14.2.0%2Fiot_ug_border_router.html
• https://devzone.nordicsemi.com/f/nordic-q-a/26003/rpi3-6lowpan_control-permission-denied

All commands were working fine until echo "connect <mac address of other device> 1" > /sys/kernel/debug/bluetooth/6lowpan_control. As seen from the websites, after this command execution, there should be bt0 interface created. But it is not visible in ifconfig -a.

Also the 6lowpan_control file is empty. But when I try to connect the other device using the command hcitool con after executing above command, I am able to see the desired connections in the terminal, still no bt0 device available. I have even tried with the command ifconfig bt0 add 2001:db8::1/64 but resulted with the error SIOGIFINDEX: No such device.

How to resolve this problem?

Note: I think I am facing this same issue.

[Jørgen Holmefjord]

Hi,

Did you use the Raspbian distro straight from the webpage, or did you compile the kernel with bluetooth_6lowpan module as described in the documentation? The documentation is a bit outdated, and you should not have to do any kernel compilation with later versions, as bluetooth_6lowpan is included by default.

Also, did you use sudo with the ifconfig command? Did you follow the instructions on this page?

Best regards,
Jørgen

[lucidlynx]

Hi,

Thanks for the response.

Yeah, I have not compiled any new kernel as I came to know that bluetooth_6lowpan module available in downloaded Raspbian distro. I just used the command modprobe bluetooth_6lowpan to load the kernel module.

Thanks for asking but I am working as a root so I have not used 'sudo'. And I followed all the steps from the mentioned link still unable to see bt0.

Inserted a error screenshot  that I am facing below:

[Jørgen Holmefjord]

Have you made sure that the address is correct? Can you post the output of 'hcitool lescan' command?

[lucidlynx]

Yes I made sure. Output of commands attached below. The radvd.service status throws error after I added the lines in radvd.conf as suggested in this link.

I just have a doubt. As Rpi3 have a built-in Bluetooth module, I did not use any external Bluetooth LE USB dongles. I assume Rpi3 has in-built functionality of Bluetooth dongles. Am I wrong or is it fine to use built-in Bluetooth module?

[lucidlynx]

Hey,

A small update. The connection I am seeing in hcitool conn command disappear after a few seconds (around 30 sec). Also the Bluetooth indicator LED in the device is not turned ON after echo "connect <mac address of other device> 1" > /sys/kernel/debug/bluetooth/6lowpan_control command.  From this, I clearly know that the above command was not able to connect my other Bluetooth device

But I was able to connect the same device and able to see the Bluetooth indicator LED ON while using bluetoothctl commands.

Please help me to resolve this problem at the earliest.

[Jørgen Holmefjord]

I have used the built-in BLE of RPi3 for this purpose before, you should not need any external Bluetooth module.

Can you provide a sniffer trace of the connection between the device and the RPi? You can use the nRFSniffer v2 for doing the capture.

Which firmware are you running on the device that you are trying to connect?