Can't find "bt0" on Raspberry Pi 4

RE: Can't find "bt0" on Raspberry Pi 4

Krishster — Wed, 06 Sep 2023 18:24:17 GMT

Hi Lin. I am facing the same issue that the bt0 interface does not show up. Can you please let me know what was the issue you faced and how you got the interface when you did ifconfig bt0

RE: Can't find "bt0" on Raspberry Pi 4

Lin Bencheng — Fri, 12 Mar 2021 18:44:55 GMT

Thanks! Jorgen
I can find the "bt0" on my RPi 4
I uploaded the MQTT publisher hex file to my nRF52840
So I could find the "bt0" and ping
Thanks again.

RE: Can't find "bt0" on Raspberry Pi 4

Jørgen Holmefjord — Fri, 12 Mar 2021 16:04:42 GMT

No, I did not do andy radvd configs, only the commands I listed on a clean install.

What are you running on the nRF52840? If you are running the normal Nordic HRM example, this does not run 6LowPAN/IPv6, and will not work together with the IoT commands. If you want to connect a non 6LowPAN device, you can search google for bluez and gatttool.

RE: Can't find "bt0" on Raspberry Pi 4

Lin Bencheng — Fri, 12 Mar 2021 13:40:24 GMT

Hi, Jorgen. Thanks for your effort
Really great! , You got the "bt0" on Rpi 4 and Raspberrian OS.
You gave me the conviction of my project!
However, Very strange. I still can't get the "bt0" interface.
I really don't know where is the issue

now I am thinking perhaps there is some issue with this RAVID installation.

interface bt0

{

AdvSendAdvert on;

prefix 2001:db8::/64

{

AdvOnLink off;

AdvAutonomous on;

AdvRouterAddr on;

};
}

I am not sure this conf file installed correctly.
Anyway, I followed the guidance of this installation.
Did you also install this RAVID conf file on your RPi 4?

RE: Can't find "bt0" on Raspberry Pi 4

Jørgen Holmefjord — Fri, 12 Mar 2021 09:04:10 GMT

Hi,

I tested this out on a RPi4 with the same OS version, and a nRF52840 DK running the IoT CoAP server example.

These commands works on my end:

pi@raspberrypi:~ $ sudo -i

root@raspberrypi:~# modprobe  bluetooth_6lowpan

root@raspberrypi:~# echo 1 > /sys/kernel/debug/bluetooth/6lowpan_enable

root@raspberrypi:~# echo 1 > /proc/sys/net/ipv6/conf/all/forwarding

root@raspberrypi:~# hcitool lescan
LE Scan ...
00:F5:E7:B0:90:9A CoAP_SRV
00:F5:E7:B0:90:9A (unknown)

root@raspberrypi:~# echo "connect 00:F5:E7:B0:90:9A 1" > /sys/kernel/debug/bluetooth/6lowpan_control

root@raspberrypi:~# ifconfig bt0
bt0: flags=4161<UP,RUNNING,MULTICAST>  mtu 1280
        inet6 fe80::dca6:32ff:fe36:5978  prefixlen 64  scopeid 0x20<link>
        unspec DC-A6-32-36-59-78-00-00-00-00-00-00-00-00-00-00  txqueuelen 1000  (UNSPEC)
        RX packets 1  bytes 28 (28.0 B)
        RX errors 0  dropped 2  overruns 0  frame 0
        TX packets 19  bytes 1783 (1.7 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

root@raspberrypi:~# ping -6 fe80::dca6:32ff:fe36:5978
PING fe80::dca6:32ff:fe36:5978(fe80::dca6:32ff:fe36:5978) 56 data bytes
64 bytes from fe80::dca6:32ff:fe36:5978%bt0: icmp_seq=1 ttl=64 time=0.132 ms
64 bytes from fe80::dca6:32ff:fe36:5978%bt0: icmp_seq=2 ttl=64 time=0.085 ms
64 bytes from fe80::dca6:32ff:fe36:5978%bt0: icmp_seq=3 ttl=64 time=0.073 ms
64 bytes from fe80::dca6:32ff:fe36:5978%bt0: icmp_seq=4 ttl=64 time=0.070 ms

Best regards,
Jørgen

RE: Can't find "bt0" on Raspberry Pi 4

Lin Bencheng — Sat, 06 Mar 2021 10:21:28 GMT

Sorry, The Raspberry Pi OS version : 2021.1.11 released

RE: Can't find "bt0" on Raspberry Pi 4

Lin Bencheng — Sat, 06 Mar 2021 10:18:31 GMT

Thanks for your reply

I am using Raspberry pi OS full (2021.1.21 released).
I tried the old version of Raspberrian OS, But if I install the old version, My RPi 4 doesn't start OS.
Yes, This new OS support 6LowPAN as default.
I can find my nRF52 DK board with this command on RPi 4
hcitool lescan
Then also this command works
echo "connect 00:AA:BB:XX:YY:ZZ 1" > /sys/kernel/debug/bluetooth/6lowpan_control
After this
when I tri this command
ifconfig
I couldn't find the bt0.
Of course, I created the RAVID configuration file on the etc folder

interface bt0

{

AdvSendAdvert on;

prefix 2001:db8::/64

{

AdvOnLink off;

AdvAutonomous on;

AdvRouterAddr on;

};

As you can see, I couldn't connect to nRF DK
but can't find bt0 interface
I hope your news
Thanks

RE: Can't find "bt0" on Raspberry Pi 4

Jørgen Holmefjord — Fri, 05 Mar 2021 12:44:45 GMT

Hi,

Which OS are you running on the RPi 4? As far as I know, 6LowPAN support should be enabled by default in Raspbian releases the last few years, no need to build the kernel as described in the docs.

Did you check if a connection was actually established with the device on the address that you passed to 'echo "connect' command? Could you capture a sniffer trace to see what happens on-aur between the RPi and the nRF52840?

Best regards,
Jørgen