Issue connecting to WiFi AP using the web GUI off the Pi Image V14 (Pro 0.91.0)

armega

Seems like it's happening to me as well for some reason...  I have a very stable Access Point and when I try to use the Repetier-Server web GUI to connect to said AP it does the following (note:to set all this up I have my LAN connected)...

• Shows all the APs I have set up
  I created a few for testing other things, 2.4Ghz, 5Ghz, ap name "TESTING_123", ap name "TESTING", security WPA2/PSK TKIP+AES
• I click on the AP I want to use (SSID: TESTING, WPA2/PSK TKIP+AES).
• I select Auth method: PSK2
• Type in my password.
• Hit "Save"
• "New connection data stored" message apears.
• Hit "Connect"
• After about 20-30 seconds some type of popup flashes for about half a second (can't see what it says) but looks like some type of red circle with a slash through it possibly?
• After about 5-10 more seconds a message in blue at the top appears "Unconnected".  Then about 5 seconds later it disappears.
• Goes back into AP mode as SSID "RepetierServer".

Ideas?

armega

Just figured it out.  I'm not sure why this works but it does...  My AP is a very stable AP and I would not see why it would "randomly disconnect" or become a "broken" connection.  But nevertheless, the secret sauce is clearly laid out on the Pi Image page (https://www.repetier-server.com/download-images/) under the section called "WLAN connection problems".

• Open up Putty or any other SSH/Telnet client.
• Connect to your Repetier-Server Pi.  Ex: I needed to connect to 192.168.1.123:3344
• Login with username "pi".
• Password: "raspberry".
• Type the command "sudo nano /usr/local/Repetier-Setup/bin/manageWifiAccess".
  
• Once editing the file, search for "connect)".  You can do this by pressing Ctrl+W in Putty.
• Find the line after that which starts with "nmcli connection delete"...
  
• Comment the line out by adding a # to the start of the line.
• Exit (Ctrl+X), Save.
• Type command "sudo reboot".

Then try the whole adding of a WiFi AP process again.  Works like a charm.

Side note, I also found it helpful (until I had my touchscreen installed and working great) to enable the mouse on the Pi GUI.

• Type command "sudo nano .bashrc".
• Once editing the file, search for "xinit -- -nocursor".
• Comment out that line.
• Exit (Ctrl+X), Save.
• Type command "sudo reboot".

This will bring back the mouse to help debug.  Want it back off, then un-comment that line again.

armega

Just in case anyone needed it, I finally found out what was popping up on me and disappearing in under 1 second.



Not that it matters any more but just thought I would share.  "Connection lost"!

Repetier

The frontend establishes a websocket connection to server. Everytime the socket gets closed the connection lost message appears. As it states it will retry automatically until it is connected again. Typical reasons to appear is server died or internet connection to server got interrupted somehow. Server will also disconnect if there is no response after some seconds (ping alive).

armega

Thanks for the followup.

Pounii

Hi, I tried what suggested here from armega and the documentation but when I put #, after the reboot repetier said that can't see any network, both wlan and ethernet! .-. I removed the # and now it can see the network again, but still the problem, wifi very unstable.

Repetier

Have you already updated to 0.91.2? It has new wifi manager and also improved wlan handling.

If you run iwconfig in console you see connection speed. How much do you have? There is still the chance of having bad connection so drops are for quality. As far as I can say quality is not so good as with my mobile at same spot.

Pounii

yes, running 0.91.2. Also if i try to do an hotspot nearby my raspberry the connection drop down, but AP mode working fine so the module is ok.

Repetier

And what does iwconfig say if you are connected with wifi. For comparison here what I see with a printer close to router:

Mode:Managed  Frequency:2.417 GHz  

          Bit Rate=108 Mb/s   Tx-Power=31 dBm   

          Retry short limit:7   RTS thr:off   Fragment thr:off

          Power Management:off

          Link Quality=67/70  Signal level=-43 dBm  

          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0

          Tx excessive retries:16590  Invalid misc:0   Missed beacon:0

Interesting is  Link Quality=67/70 which shows how good connection is and resulting bit rate (108 here)

Pounii

even if I make an hotspot nearby  the raspberry, connection drop down immidiatly and is unstable, I will post a screenshot; the AP mode from repetier server works fine, so I continue to think that is not an hardare issue. Could be a problem caused from the fact that I installed repetier server in raspberry pi 2 and then I moved the card on the raspberry pi 3 b+?

Pounii

Repetier

Changing the pi should be no problem. Our image works from pi 0 - 3+. But how was connection on the Pi 2? Was it stable there?
Your screenshot shows a good connection. As long as linux keeps it it should continue to work. All the server does is switching to ap if it does not see that you are still connected. I guess you see the connection reappear after a while when you get your disconnects? Server will switch if linux command "iwconfig" does return a mode unequal "Managed" for a longer period.

What you can try is once wlan is setup working run on ssh
sudo mv /usr/local/Repetier-Setup/bin/manageWifiAccess /usr/local/Repetier-Setup/bin/manageWifiAccess_off
and reboot. Then server has no way to modify your network. Then all disconnects are related to linux/router.
sudo mv /usr/local/Repetier-Setup/bin/manageWifiAccess_off /usr/local/Repetier-Setup/bin/manageWifiAccess

will give it back to you in case you need to modify something or need to configure.
ethernet connection is your fallback if wlan should for some reason not connect again.

You can also check /var/log/syslog on times when you have disconnects. It will log any wlan modification like connection lost, reconnect etc.

Pounii

on pi 2 I didn't use wifi, swapped on pi3 just for it. I'm trying right now your command and seems working fine, thank you!  

Pounii

Another question: there is a way to force wifi on a particular channel? I remember that when I was connected with channel 7, the connection was better.

Repetier

Channel is defined by your router and not by the clients. And yes if a channel is frequently used in neighbourhood a more distant not so much used channel can work better. Some router even switch dynamically the channel to least used one.