Connection to UDOO board periodically down

Discussion in 'Troubleshooting' started by Murat, Jul 28, 2015.

  1. Murat

    Murat New Member

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    My UDOO board and my laptop are using the same wifi.
    I connect to my UDOO board via ssh on the terminal on my laptop.

    ssh ubuntu@192.168.2.33
    response: host is down OR operation timed out.
    This happens often and I tried using a different UDOO board and the same thing happens. Sometimes I am able to connect, but it will go down again after a while.

    I need a stable connection, has anyone else had this problem and do you know how to fix it
     
  2. fetcher

    fetcher Member

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    How far is the Udoo from your wireless router or access point? I'd suspect a poor signal as the most likely culprit. Due to less than ideal antenna design and placement, the Udoo's built-in Wifi module can get worse reception than some other devices would at equal range. Of course, mouting the Udoo in a metal case will severely degrade the Wifi signal.
    While ssh'ed into the Udoo, try this command to check your signal quality and strength:
    Code:
    /sbin/iwconfig wlan0 |grep -ie level -e rate
    It should report something like

    Code:
      Bit Rate=54 Mb/s  Tx-Power=15 dBm
      Link Quality=52/70  Signal level=-58 dBm 
    Also try pinging the udoo from your laptop, and leaving that running for a while, 5-10 minutes or so, to measure packet loss.

    Running 'dmesg' on the Udoo to check for any kernel driver errors relating to the Wifi / 802.11 subsystem would be a good idea too.

    If the signal is poor, using an external USB adapter, or else mounting the supplied module (which is USB also, just using a nonstandard connector) further away using an extender cable may help.

    If running a cable isn't out of the question, wired Ethernet should be more reliable, as well as faster.
     
  3. sirrab

    sirrab UDOOer

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    After adding an external antennae to my metal chassis that houses my quad UDOO, I get:
    Bit Rate=72.2 Mb/s Tx-Power=20 dBm
    Link Quality=63/70 Signal level=-47dBm

    There is a thread here that shows the picture of my mod. Search my screen name, to find it.
    And it does make a difference!
     
  4. Murat

    Murat New Member

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    When I type /sbin/iwconfig wlan0 |grep -ie level -e rate
    it returns
    Bit Rate=57.8 Mb/s Tx-Power=20 dBm
    Link Quality=47/70 Signal level=-63 dBm

    I will use ethernet for now as I continue my project but I will eventually need to go wireless because I am building a robot.
     
  5. fetcher

    fetcher Member

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    Murat, those signal numbers actually look pretty good, so barring intermittent interference there's probably something else going on. Do you see any odd messages relating to wireless in 'dmesg', or any packet loss in a ping test?

    sirrab, good idea with the antenna. I noticed the module had solder pads for some sort of small coax connector (u.FL?) that wasn't populated. Noticing your high channel bit rate, does the onboard module actually support 802.11n, or are you running it in a "turbo" 802.11g mode w/ 40MHz channel width?

    On my main Udoo, which doesn't need client-side Wifi (though it handles routing for some external Ubiquiti access points) I just removed the module, using its header for a 4th USB port. If anyone wants to try this, note that the pin positions are offset by one compared to the 3rd-USB header, with some extra, unconnected ones also. Check schematics...
     
  6. orfeus

    orfeus New Member

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    Hello Murat, I had a similar problem.
    You can try to uninstall the default Network Manager and replace it with WICD. This solved my problem with not responding UDOO board.
     
  7. sirrab

    sirrab UDOOer

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    The antenna connector was added, yes. I'm not sure how to answer what mode the Wi-Fi module is in. I have done nothing special to configure it. I suspect my router may be higher speed than others.
     
  8. Andrea Rovai

    Andrea Rovai Well-Known Member

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    Did you Murat manage to solve the problem by following the suggestions?
     
  9. Murat

    Murat New Member

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    I installed wicd and removed network manager.. It seems to be the same problem, I think it may be because of my router being not very good. Thanks for the help everyone.
     
  10. Andrea Rovai

    Andrea Rovai Well-Known Member

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    Hi there Murat,
    may you verify if the router is working?
    If the router is not working, please open a ticket.​
    CHeers
     

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