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XBee and Hologram LTE: issues connecting to internet

Home Forums Mayfly Data Logger XBee and Hologram LTE: issues connecting to internet

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    • #14352
      Letsid
      Participant

      I am unable to connect to the internet (and therefore monitor my watershed).  After reading some other posts, it seems that I am not alone.  However, I am still having problems even after reading some of the tips.  Here are links to the forums that I have read:

      1. https://www.envirodiy.org/topic/xbee-r410m-cant-connect/
      2. https://www.envirodiy.org/topic/connecting-xbee3-lte-to-the-internet/
      3. https://www.envirodiy.org/topic/difficulty-connecting-to-mmw-with-lte-adapter/

      My unit hardware is (photos attached):

      My code is from the mmw example: https://github.com/EnviroDIY/ModularSensors/tree/master/examples/logging_to_MMW

       

      Upon building the code to the Mayfly, it begins to set up the sensors and the RSSI light stays on for what seems like the full two minutes.  It then turns off and the device alerts me that it “could not connect to internet for clock sync” and is “putting modem to sleep”.

       

      I realize this is the same problem as posted in the second forum, linked to above.  In that post, it is recommended to change the allowable connection time — “by changing the time in line 302 ‘if (modem.connectInternet(120000L))’.” I scanned the code in the mmw sketch and cannot find this command.  Has the sketch been updated since that forum post?

       

      Another tip, mentioned in the 3rd post linked above, was using “DigiXBeeLTEBypass”.  I tried this and the result was the same.

       

      Advice?

    • #14356
      Sara Damiano
      Moderator

      Woops, yes, the example has changed since then.  Sorry about that.

      And, yes, you’re definitely not alone.  I think issues with LTE connections are the top forum topic here.  The LTE XBee3’s are so much trouble.  I wish I could find something better.

      From your pictures, your hardware connections look right.  🙂

      As you’ve read, the first connection can take near forever.  In the last update I simplified the clock sync, but that removed the control over how long to wait.

      I put up a new program for you to try to see if you can get a connection:  https://github.com/EnviroDIY/ModularSensors/blob/master/tools/LTExBee_FirstConnection/LTExBee_FirstConnection.ino  It will set up the XBee, the carrier profile, the APN and then just sit and wait forever for a connection.

       

    • #14359
      Letsid
      Participant

      Thank you for taking the time to put that together!  It worked… sort of.  My SIM successfully connected to the internet!  It took maybe 30 minutes.  My signal quality is listed as -45.

      After successfully connecting, I restart the Mayfly and build in the MMW example.  This code fails to connect and I get the same result as before ( “could not connect to internet for clock sync” and is “putting modem to sleep”).  I then re-try the code you provided above and it takes another 30 minutes or so to connect. And repeat.

      Is there a way to do the ‘wait forever to connect’ strategy within the MMW example?  Is this not an ideal solution?

      P.S. I originally bought three of the Digi XBees.  I have tried two of them, repeating all the steps above.  They are acting the same.

       

    • #14360
      Sara Damiano
      Moderator

      -45?  The nominal RSSI range for the XBee3 is -113 dBm (really bad) to -51 dBm (excellent) so -45 either means your signal is *amazing* or not valid.  I made a small change to that program to continuously print the quality so you can watch it to see if it changes while trying to register.  When running that first connection sketch, are you seeing lots of 22 or 23responses (searching for the network) or are you getting 25‘s (denied)?  Can you copy the output from running for a minute or two and post it?

      Your pictures of your set-up look good.  The battery’s not dead, right?  Try (gently) wiggling the antenna to make sure its secure.

      Are you sure there is AT&T signal available?

    • #14361
      Letsid
      Participant

      The battery I am using is basically straight from the box so I was under the assumption that it was about 50% charged.  I have not had the opportunity to complete the solder on the Voltaic solar panel.  The antenna has been gently wiggled!  I should also note that I did not remove the antenna when testing the second Digi XBee (to avoid unnecessary damage).  So, I have gotten the same result with two different antenna, both with a seemingly secure connection.  I am not certain that there AT&T is available but when it did connect, and came up on my Hologram account, I assumed there was.  Also, I tried connecting to Verizon and had no luck connecting.

      Attached are snapshots of the serial monitor as it moves through trying to connect.  I cut it up because it was pretty long.  I see no 22s, 23s or 25s.  But I do see many zeros.  These changed into -93 for a while and then to -45 and then back to zeros (as you can see in the pictures).  Is this what you were looking for?

       

    • #14366
      Sara Damiano
      Moderator

      Woops, sorry, the XBee uses carriage returns instead of new lines so the 22/23/25 isn’t appearing.

      Add this to your platformio.ini:

      Your log will suddenly get a lot longer.

    • #14367
      Sara Damiano
      Moderator

      But it seems like you might have kind-of low signal, if that -93 is valid.  Does anyone around have an AT&T cellphone?  Do they have ok signal?

      Hologram doesn’t work on Verizon.  Sometimes they say the do, and for a while we actually got it to work, but usually it’s only AT&T.

    • #14368
      Sara Damiano
      Moderator

      You can try adding a network scan before the “waiting for network registration” section.  It won’t help you connect, but it should show what networks have signal.

       

    • #14370
      Letsid
      Participant

      Got it!  So this time I left it long enough to connect (or I think it is connecting).  Attached are snips of the monitor.  It repeats for quite a while and then right at the end it changes.  So, pictures 3 & 4 are almost consecutive.

       

      I commented back after fixing my ini file and did not reload the page and didn’t see your other comments!  I will try the network scan tomorrow!

    • #14375
      Sara Damiano
      Moderator

      Wahoo, that’s connected!  *Usually* after you’ve made a few connections it connects more quickly the next time, but signal quality of -81 isn’t stellar, so it might still be somewhat slow.  Are you testing at where you’re going to deploy?  If so, you might want to take some time fiddling with just the right arrangement of the antenna and other wires to maximize your signal – you don’t want other wires to cross the antenna and I think you want a slight curve in the antenna’s cable.  Small movements can make a surprising difference.  If you’re planning to deploy somewhere else, and it’s easy to do so, you might want to run that “first connection” program again at your deployment location to see how long the connection takes.  Hopefully it will be faster.  Concrete office walls do a pretty good job of blocking cellular signals.

    • #14386
      Letsid
      Participant

      Wanted to send an update: the XBee is now connecting to the internet in a timely manner!  I saved the testing code for my future units.  Thanks again!

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