Wifi frozen

Hi all,

First of all, nice improvements in the new EmonCMS! 

I installed the emonsd-20feb2016 image, everything works as expected till I tried to connect to another wifi. During the first start I could see all other networks, but after connecting only the known network is visible/connected.

It seems like it is frozen or something. Scan won't work, neither the other buttons on the wifi page.



johlhausen's picture

Re: Wifi frozen

I'm having the same issue. Looking for a solution...

johlhausen's picture

Re: Wifi frozen

Hope you're comfortable with the command line. I fixed it by ssh-ing into my Pi, switching it to read/write mode by typing "rpi-rw," and editing wifi settings through "sudo nano /etc/wpa_supplicant/wpa_supplicant.conf" (link)

It will list a bunch of networks. Try deleting a network and reloading the emoncms page, that network should disappear. Then, copying the format that's there already, add the name of the wifi network you want to use. That network should then appear when you refresh the emoncms wifi page... enter the password, connect, and refresh. That should do it.

Don't forget to switch the Pi back to read only mode like I did. Type "rpi-ro"

glyn.hudson's picture

Re: Wifi frozen

Oh dear. Sorry to hear that. I have been unable to re-create the issue here. Please, could I ask a few questions to try and debug this: 

  1. Are you both running emonsd-20feb2016? 
  2. Are you using the standard Wifi Edimax Wifi adapter?
  3. How many networks to you have in the list? (I only have a couple). 
  4. Have you performed an emonPi update to pull in the latest updates to the emonPi module?

Have you remembered to tick the checkbox to the left of the WiFi network before connecting? 

Just to get things clear, the steps to re-create the issue are:

  1.  First network scan works fine? 
  2. Connect to a network, network connects fine? 
  3. Upon re-visiting the WiFi config page, the status and WiFi network list is blank?
  4. Manually entering WiFi details in WPA file is required to connect to any additional networks 
Bart's picture

Re: Wifi frozen

@johlhausen and @Glyn,

My Pi is working but without internet, so I can't test it.

1. Yes 20 feb sd
2. Yes, the standard from OEM
3. I had a bunch while configuring, but now only the first chosen/working
4. Yes, I did the update via the browser when I had internet.

About the checkbox, I checked only the box of the now visible and working wifi connection. Where is it needed for? 

1. Yes it worked fine, worked as good in emoncms8.5
2. Connecting by Ethernet works direct and only to the first connected wifi works
3. No connection information available. Scan, start, stop etc. don't give any reaction
4. Not tried yet, what Johlhausen mentioned.


johlhausen's picture

Re: Wifi frozen

  1. Embarrassingly, I'm not sure how to know what release I'm running. I put the stable 17Jun15 release on months ago and I clicked update emonPi yesterday before attempting to connect to my new WiFi.  Figured out how to check: yes, it is 17Jun15
  2. I have had the same issue with the standard Edimax adapter as well as a non-standard one.
  3. 12 networks in my list
  4. Yes, immediately before trying to connect to a new WiFi network.

I did remember to tick the checkbox.

Steps to re-create:

  1. First network scan worked fine when I did it months ago. I'm in the process of downloading 20Feb16 so I will update if the first network scan does not work.
  2. Same as 1.
  3. Re-visiting the WiFi config page, status and connection info is blank. However, the list of WiFi networks "available" is the same as it was when I scanned the first time. Similar to Bart, the buttons are all unresponsive.
  4. Manually entering WiFi details in WPA file worked for a Pi that I had NOT performed an emonPi update on. On the Pi I had performed an emonPi update on, even manually entering WiFi details does not allow me to connect to additional networks.
glyn.hudson's picture

Re: Wifi frozen

Thanks a lot for your help. This is great. I'll do my best to debug this.

I have just tested with the Edimax dongle and RasPi3 with Broadcom adapter and have been unable to re-create. I am running the 20Feb16 image. 

@Bart, the checkbox is to select which networks you want the emonPi to try and connect to, i.e if the first one fails it will try and connect to the next. Checkbox is also needed to select an open-access un-encrypted network.

glyn.hudson's picture

Re: Wifi frozen

I can't recreate the issue on my home test emonPi, see screencast: https://drive.google.com/file/d/0B9yLIKTN3csqTVZpQThVOEZHTjA/view

Please could you watch my screencast and let me know if you notice anything different about my setup to your setup.

If you have SSH access could you post output of:

$ ifconfig wlan0 


$ iwconfig wlan0

On my system I get :

pi@emonpi:~/emonpi $ ifconfig wlan0 
wlan0 Link encap:Ethernet HWaddr 74:da:38:2e:1c:ac 
inet addr: Bcast: Mask:
inet6 addr: fe80::76da:38ff:fe2e:1cac/64 Scope:Link 
inet6 addr: fdfa:fd37:1aa5:0:a6dd:34c6:9d25:d75c/64 Scope:Global 
RX packets:2475062 errors:0 dropped:2369 overruns:0 frame:0 
TX packets:2404222 errors:0 dropped:0 overruns:0 carrier:0 
collisions:0 txqueuelen:1000 
RX bytes:607583698 (579.4 MiB) TX bytes:982754601 (937.2 MiB)

pi@emonpi:~/emonpi $ iwconfig wlan0 
wlan0 IEEE 802.11bgn ESSID:"Crumble" Nickname:"<WIFI@REALTEK>" 
Mode:Managed Frequency:2.447 GHz Access Point: 7C:4C:A5:2E:7C:ED 
Bit Rate:72.2 Mb/s Sensitivity:0/0 
Retry:off RTS thr:off Fragment thr:off 
Power Management:off 
Link Quality=100/100 Signal level=79/100 Noise level=0/100 
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 
Tx excessive retries:0 Invalid misc:0 Missed beacon:0

TrystanLea's picture

Re: Wifi frozen

Also having trouble replicating this. Can anyone see any errors in the browser console window when viewing this page? The browser network tab is another good place to look. Do any of the request responses return errors? I'll see if I can add some more error checking to the module.

Bart's picture

Re: Wifi frozen

I have watched the screencast and the first difference is, that I had only one network listed. The second is, that all the fields are empty, ip, mac, etc. My Pi is now running a measuring job, so I can't access it now unfortunately. (connected with a router without internet connection) But If I remember it well, the wifi page remains blank instead of changing in the green fields as your screencast.

So it looks that EmonCMS isn't able to read/communicate.

Probably I'm next Friday in the position to check the WiFi configuration and the errors in the browser console.

glyn.hudson's picture

Re: Wifi frozen

We have pushed a couple of bug fixed to the Wifi module. Please pull in these fixes using emonpi update and let me know if the issue persists. 

Bugs fixed include:

  • Support SSID's with white spaces 
  • Wifi config now prints output to browser developer console to help with debugging 

Please let us know the output of developer console when trying to connect to Wifi network. Be sure to un-check networks you don't wan to connect to. 

Bart's picture

Re: Wifi frozen

Today I was able to visit my setup and check some things. I have attached a screenshot of the wlan configurations, what looks fine to me.

I had also another issue for the second time (see screenshot). After a reboot the problem was solved, but probably not for the last time...Automatic reboot after dead main thread would be nice. 

So I wasn't able to update and copy the printouts of the wifi debugging information. Tomorrow, I'll try to visit again to update and copy the output of the Wifi debugging.




Bart's picture

Re: Wifi frozen

I have checked again my pi and unfortunately even more errors occurred, the main thread was dead and after a reboot it didn't save the feeds. Even after restarting the feedwriter.

Updating the Pi also didn't result in a working wifi. So I thought a clean install will be the best and fast solution. I did that and all the problems were solved. 

Due to a lack of time I can't afford another week of missing data so I returned to 17juni2015 image...


glyn.hudson's picture

Re: Wifi frozen

Hi Bart, 

Good to hear Wifi has been fixed. I recommend starting a new thread to discuss the latest bug. All I can recommend without seeing specifics is make sure you run emonPi update to pull in any bug fixes. I would be interested to hear if you manage to obtain any further insight into the 'dead thread' issue. It's a new one for me.

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