Forum Sensor.Community

WiFi connection problems

I replaced the wifi router from Asus RT-AC87U to Asus RT-AX86U. Kept old wifi ssid and password. And got problems with the sensor - it does connect to the new router, it does request the ip from dhcp, but no data is transmitted, no ping, no connection to the web interface of the sensor is possible.

The sensor does not bring his AP online, so from his side it looks like it’s connected to the router. Switching down the router forced the sensor to switch its AP and let me to reconfigure it to use the old router.

Switching on the old router brings the sensor online.

All other smart home devices (both different Sonoff’s and self made esp8266 with same boards as in the sensor) successfully connect to the new router.

The sensor is in 3 meters from the router, so the signal is perfect.

What can be the problem? Should I play with router settings or may be I should change from 802.11n to b or g mode (I found some discussions regarding possible problems with n mode in ESP8266)?

Can you read the log from the USB cable (Arduino IDE or screen in Terminal) ? I would like to see waht the sensors tells.

Did you also use the “discovery” function of the firmware flasher?

Connecting to usb requires to dismount the sensor, it is powered not via usb cable. But if no other solution is possible - will do.

Auto discovery does detect the new router wifi network, but changes nothing in the situation.

My mistake, you were asking about auto discovery in flasher, my reply was about the config in sensors web interface, I did not try the flasher…

Does the sensor appear (you have to be on the same router) ?

Capture d’écran 2021-02-25 à 11.56.33

Not at home at the moment, will check later.

Interesting… I had similar issues with the NAM sensor and connecting it to my Ai-Mesh consisting of RT-AC86U after upgrading those to the latest Merlin build (which involved a switch to the current Asus codebase). I don’t remember exactly what the symptoms were but after placing the sensor next to the repeater in the garden (Asus N66U running a much older FW) everything worked as expected. As NAM is a fork of airrohr and not exactly the same, I would suspect that our Asus routers do something silly here.

Maybe it’s about time to start a thread at SNB Forums…

Also have Merlin, on both routers. And on AC87U it is working ok. What version of firmware you had problems with? AC86U is on 384? The AC87U did not move to 384 from 382 due to some technical problems (and they were discontinued a long time ago). And the new RT-AX86U is on 384…

My setup is running on 386.1.

Opps. Looks like I was wrong with “RT-AX86U is on 384”. It’s also on 386.1.

Please check your logs for

Deauth_ind <airrohr’s MAC address> status: 0, reason: Class 2 frame received from nonauthenticated station

I saw those when I had similar issues.

I have the same:

Feb 25 21:30:10 wlceventd: wlceventd_proc_event(469): eth6: Deauth_ind 40:F5:20:0A:D4:1F, status: 0, reason: Disassociated due to inactivity (4)
Feb 25 21:30:12 wlceventd: wlceventd_proc_event(469): eth6: Deauth_ind 40:F5:20:0A:D4:1F, status: 0, reason: Class 3 frame received from nonassociated station (7)
Feb 25 21:30:13 wlceventd: wlceventd_proc_event(505): eth6: Auth 40:F5:20:0A:D4:1F, status: Successful (0)
Feb 25 21:30:13 wlceventd: wlceventd_proc_event(534): eth6: Assoc 40:F5:20:0A:D4:1F, status: Successful (0)

The flasher does not detect the sensor.

Solution found. Strange, but working - switched Channel bandwidth from 40 Mhz to 20 Mhz. Swithing to 20/40 Mhz did not work which is very strange, as this is the option set on the old router…

Cool - thanks for posting the solution! Glad it’s working now.

The problem is that I do not see in esp8266 specs anything about the limit of 20Mhz. So I have a solution, but not an explanation…

The joy was premature. The sensor remains online for several minutes or even seconds, which allows sometimes even to enter the web interface, but then the connection is dropped.

As I see from the router logs after that the sensor constantly requests the ip via dhcp, the router grants it, but in a second it requests the ip again and again.

I shall dismount it on weekend and look what is in the sensor console output.

Give us all the specs of your power supply. How many mA ? What kind is it ? I am quite sure it comes from there now.

It’s a MEAN WELL RS-25-5 (

5A. It was used to power 3 different ESP8266 devices at the same time with no problems, now only the sensor is connected to it.

And I do not think the problem is with the power supply, as the sensor is perfectly working with the old router, which is now located much far from the sensor then the new one, so it does not look like lack of power

You’re right it is a kind of PSU for arcade cabinet. It should be good…

I read this:
Feb 25 21:30:12 wlceventd: wlceventd_proc_event(469): eth6: Deauth_ind 40:F5:20:0A:D4:1F, status: 0, reason: Class 3 frame received from nonassociated station (7)
Is there a kind of WPS option in you’re router? Do you have a 2X2 networks (normal 2.4 & 5 + guest 2.4 & 5)?