unstable connection from IoT example: ipv6_icmp to RPI border router

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 I use nRF52832 DK as the node and RPI as the border router.

I fowllowed the guide setup the border router and flash the example ipv6_icmp to the nRF52832 DK.

The connection can be established. The local-link address is right.But I can not find the global address.

And most important thing is that the connection can only last about a few seconds, then disconnected unexpectly.

Is there something wrong ?

mount -t debugfs none /sys/kernel/debug
echo 1 > /sys/kernel/debug/bluetooth/6lowpan_enable

echo "connect 00:E9:92:E1:xx:xx 1" > /sys/kernel/debug/bluetooth/6lowpan_control

/home/pi# ifconfig bt0
bt0: flags=4161<UP,RUNNING,MULTICAST> mtu 1280
inet6 fe80::dca6:32ff:fexx:xxxx prefixlen 64 scopeid 0x20<link>
unspec DC-A6-32-xx-xx-xx-00-00-00-00-00-00-00-00-00-00 txqueuelen 1000 (UNSPEC)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 6 bytes 361 (361.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

/home/pi# ping6 -I bt0 fe80::e9:92ff:fee1:xxxx
ping6: Warning: source address might be selected on device other than bt0.
PING fe80::e9:92ff:fee1:9871(fe80::e9:92ff:fee1:9871) from :: bt0: 56 data bytes
64 bytes from fe80::e9:92ff:fee1:9871%bt0: icmp_seq=1 ttl=64 time=62.2 ms
64 bytes from fe80::e9:92ff:fee1:9871%bt0: icmp_seq=2 ttl=64 time=84.9 ms
64 bytes from fe80::e9:92ff:fee1:9871%bt0: icmp_seq=3 ttl=64 time=107 ms
......
ping: sendmsg: \u6ca1\u6709\u90a3\u4e2a\u8bbe\u5907
ping: sendmsg: \u6ca1\u6709\u90a3\u4e2a\u8bbe\u5907
^C
--- fe80::e9:92ff:fee1:9871 ping statistics ---
15 packets transmitted, 10 received, 33.3333% packet loss, time 168ms
rtt min/avg/max/mdev = 54.804/78.305/106.797/16.196 ms

/home/pi# ifconfig bt0
bt0: error fetching interface information: Device not found

[Håkon Alseth]

Hi,

 

bluetooth 6lowpan examples have been deprecated (removed) from newer nRF5 SDK versions.

Which SDK are you using?

 

The connection can be established. The local-link address is right.But I can not find the global address.

 The global address is something you assign on the host side. See here: https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.sdk5.v15.3.0/iot_ug_border_router.html?cp=8_5_1_5_5_0

And most important thing is that the connection can only last about a few seconds, then disconnected unexpectly.

Is there something wrong ?

You have to debug why the connection is lost. Does the nRF assert or similar? What does the logs state on the RPi side?

 

Kind regards,

Håkon

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I'm using the nrf52 SDK 16.0, and I follow the instructions the index you provided. 

I'd like to know why the bluetooth 6lowpan removed.

[data]

/var/log/syslog

message below repeats everytime trying to connect:

May 29 16:04:22 raspberrypi bluetoothd[5362]: No cache for 00:E9:92:E1:98:71
May 29 16:04:24 raspberrypi avahi-daemon[393]: Joining mDNS multicast group on interface bt0.IPv6 with address fe80::dca6:32ff:fed1:1e2c.
May 29 16:04:24 raspberrypi avahi-daemon[393]: New relevant interface bt0.IPv6 for mDNS.
May 29 16:04:24 raspberrypi avahi-daemon[393]: Registering new address record for fe80::dca6:32ff:fed1:1e2c on bt0.*.
May 29 16:04:24 raspberrypi kernel: [ 8085.977647] Bluetooth: hci0: link tx timeout
May 29 16:04:24 raspberrypi kernel: [ 8086.415729] Bluetooth: hci0: link tx timeout
May 29 16:04:25 raspberrypi kernel: [ 8086.819299] Bluetooth: hci0: link tx timeout
May 29 16:04:25 raspberrypi ModemManager[392]: <info> Couldn't check support for device '/sys/devices/platform/soc': not supported by any plugin
May 29 16:04:25 raspberrypi ntpd[551]: Listen normally on 36 bt0 [fe80::dca6:32ff:fed1:1e2c%22]:123
May 29 16:04:25 raspberrypi ntpd[551]: new interface(s) found: waking up resolver
May 29 16:05:02 raspberrypi avahi-daemon[393]: Interface bt0.IPv6 no longer relevant for mDNS.
May 29 16:05:02 raspberrypi avahi-daemon[393]: Leaving mDNS multicast group on interface bt0.IPv6 with address fe80::dca6:32ff:fed1:1e2c.
May 29 16:05:02 raspberrypi avahi-daemon[393]: Withdrawing address record for fe80::dca6:32ff:fed1:1e2c on bt0.
May 29 16:05:04 raspberrypi ntpd[551]: Deleting interface #36 bt0, fe80::dca6:32ff:fed1:1e2c%22#123, interface stats: received=0, sent=0, dropped=0, active_time=39 secs

[Håkon Alseth]

Hi,

 

What does the firmware itself state? Does it show any uart output that might give an indication on what the disconnect reason is?

 

Kind regards,

Håkon

[data]

Hi,

The firmware didn't use uart as output.But I checked the RTT LOG info.

I found no error in the log. I only got this message when the connection breaks:

   <info>  app: Interface removed!

   <info>  app: Physical layer disconnected.

   <info>  app: Physical layer in connectable mode.

I think the firmware runs well.The problem must happends in the RPI.

But I'm not familar with this part of RPI.

I hope I can get help from you guys.

Tanks a lot.

Sincerely regards, 

mark baum

[Håkon Alseth]

Hi,

 

Is that the only log that is shown?

Does other iot samples behave equally?

 

Kind regards,

Håkon

[data]

Hi,

The log only shows that information.I think maybe the bluetoothd involves.

I rechecked my operations with the instructions with IoT SDK: Get Started page https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.iotsdk.v0.9.0%2Fiot_getting_started.html&cp=7_4_2

nothing found.

And I rebuild router on ubuntu for RPI.The same error happends.

I have no clues to solve it.

Sincerely regards, 

mark baum

[Håkon Alseth]

Hi Mark,

 

Did you try any of the other firmware examples to see if they behave similarly?

 

Kind regards,

Håkon

[data]

Hi,

Yes, I did.

I tried ICMP, UPD, TCP and CoAP. All of these examples show the same error.

I will try on different device next.

Sincerely regards, 

mark baum

[Håkon Alseth]

Did you try to stop bluetoothd?

sudo service bluetoothd stop

 

Or maybe you have other bluetooth daemons running? "ps aux | grep blue" - see what shows up.

 

Kind regards,

Håkon

[data]

I only found /usr/lib/bluetooth/bluetoothd.

I tried to do the same operations in ubuntu os on my laptop.It runs perfectly.

I got error runs on RPI 3b and RPI 4b, whether raspberry os or ubuntu.

So, I think maybe the bluez version is too high for RPI. This will explain this info below form syslog:

    raspberrypi bluetoothd[5362]: No cache for 00:E9:92:E1:98:71

 

I will try lower version of bluez tomorrow.

Thanks for your help.