moderated Raspberry Pi wlan0 problem


Raul M0ZZM
 

Hello everyone,

I wonder is someone can help me. I have a Raspberry Pi 4 connected to an IC-7300 directly via USB cable, everything works fine except the WiFi connection via wlan0. Basically the interface connects normally to the WiFi network, however the Pi struggles to connect the internet. This doesn't only affect the web protocol but also terminal connection to the standard repositories (e.g. apt-get).

If I ping 8.8.8.8 from terminal I obtain good response, as I do if I ping a "good" domain name such as the BBC or raspberrypi.org. In light of this I am excluding a DNS configuration problem. Moreover, when I check /etc/resolv.conf, the gateway address is correct. Running ifconfig returns sensible information, including valid inet, netmask, etc. The Pi4 is the only device experiencing this problem and any mobile phone, tablet, Android, Apple, you name it, sitting next to the Pi can get good up/downstream, both on 2.4GHz and 5GHz.

I considered the possibility of some RF in the shack, however this doesn't seem to be the root cause as the problem persists even when the rig completely disconnected (USB cable unplugged, radio off, 12V DC PSU off).

Rebooting, reassociating wlan0, forgetting and setting up the Wifi network afresh, did not help. The system is up to date and everything else runs normally.

The only thing that helped was the installation od an old-ish USB WiFi dongle that I had in a drawer (identified by the system as wlan1). Once configured, everything works well so long as wlan0 remains disconnected.

Can someone please give me advice on:

1. what test I can run to reliably diagnose why wlan0 doesn't work

2. failing the above or i in case it turns out that the wlan0's RF hardware failed, how can I disable wlan0 for good so that it doesn't try to take over the WiFi connection?

Thanks for your help.

Raul M0ZZM


Cliff, AE5ZA
 

Raul,

I can’t speak for the Pi4, but my Pi3B is sensitive to the orientation of the circuit board for wifi reception. You might experiment with that aspect and see if it makes any difference.

73,
Cliff, AE5ZA

On Nov 22, 2019, at 13:04, Raul M0ZZM <m0zzm@...> wrote:

Hello everyone,

I wonder is someone can help me. I have a Raspberry Pi 4 connected to an IC-7300 directly via USB cable, everything works fine except the WiFi connection via wlan0. Basically the interface connects normally to the WiFi network, however the Pi struggles to connect the internet. This doesn't only affect the web protocol but also terminal connection to the standard repositories (e.g. apt-get).

If I ping 8.8.8.8 from terminal I obtain good response, as I do if I ping a "good" domain name such as the BBC or raspberrypi.org. In light of this I am excluding a DNS configuration problem. Moreover, when I check /etc/resolv.conf, the gateway address is correct. Running ifconfig returns sensible information, including valid inet, netmask, etc. The Pi4 is the only device experiencing this problem and any mobile phone, tablet, Android, Apple, you name it, sitting next to the Pi can get good up/downstream, both on 2.4GHz and 5GHz.

I considered the possibility of some RF in the shack, however this doesn't seem to be the root cause as the problem persists even when the rig completely disconnected (USB cable unplugged, radio off, 12V DC PSU off).

Rebooting, reassociating wlan0, forgetting and setting up the Wifi network afresh, did not help. The system is up to date and everything else runs normally.

The only thing that helped was the installation od an old-ish USB WiFi dongle that I had in a drawer (identified by the system as wlan1). Once configured, everything works well so long as wlan0 remains disconnected.

Can someone please give me advice on:

1. what test I can run to reliably diagnose why wlan0 doesn't work

2. failing the above or i in case it turns out that the wlan0's RF hardware failed, how can I disable wlan0 for good so that it doesn't try to take over the WiFi connection?

Thanks for your help.

Raul M0ZZM


Raul M0ZZM
 

On Fri, Nov 22, 2019 at 07:47 PM, Cliff, AE5ZA wrote:
my Pi3B is sensitive to the orientation of the circuit board for wifi reception.
Thanks Cliff.

I don't know the specifications (power and antenna, if any) used by the on-board WiFi on the Pi, however I suspect the issue is that the WiFi adapter's TX power is rather limited. If my conclusions are correct, essentially the Pi remains connected to the access point and is able to "check-in" but cannot be heard at the other end sufficiently well for a good two-way communication.

I relocated one of the mesh network access points in the vicinity and so far it seems to be working.


Cliff, AE5ZA
 

Great. Sounds like you’ve got the solution.

73,
Cliff, AE5ZA

On Nov 26, 2019, at 12:43, Raul M0ZZM <m0zzm@...> wrote:

On Fri, Nov 22, 2019 at 07:47 PM, Cliff, AE5ZA wrote:
my Pi3B is sensitive to the orientation of the circuit board for wifi reception.
Thanks Cliff.

I don't know the specifications (power and antenna, if any) used by the on-board WiFi on the Pi, however I suspect the issue is that the WiFi adapter's TX power is rather limited. If my conclusions are correct, essentially the Pi remains connected to the access point and is able to "check-in" but cannot be heard at the other end sufficiently well for a good two-way communication.

I relocated one of the mesh network access points in the vicinity and so far it seems to be working.