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  • Shannon – thanks for your thoughtful reply.  I’m sure I’ll be able to find the problem now.  Answering your questions:

    1. I’m not switching D22 on.
    2. Humidity is a possibility. I’ll look for corrosion and add desiccant .
    3. I’ve had ants at another location but not this one…yet.
    4. I’ll make some tests as you suggest to isolate the problem.  It mi…

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  • My stations as described above have been working fine for 3 years in the field.  I’ve had a few components fail (12-5v buck converter, XBee daughter card, resistor divider) but otherwise very stable.

    However, one Mayfly (0.5b) seems to be performing fine with 2 exceptions:

    • the red LED3 is either solid ON or dim
    • the ADC that records the 12v…

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  • After struggling with power problems for years and buying several brands of 12v batteries and also using multiple batteries in parallel, I discovered I was looking in the wrong area.  The solution for me was to find where power was being used and replacing inefficient modules with efficient ones.  And the problems I found were surprising and p…[Read more]

  • Cal replied to the topic Stronger cell antenna? in the forum Mayfly Data Logger 2 years ago

    We just had an experience with antennae that might interest others.  We have a dozen sensor stations in the field measuring water level of lakes in north western Michigan.  Each station has an SDI-12 water level sensor connected to a Mayfly with a Digi XBee3 Cellular LTE-M/NB-IoT modem using a $3.00 antenna from Adafruit  …[Read more]

  • All my devices came back online after 3:30 am ET – outage was around 15 hours by Hologram. I’m going to look at alternate providers if this happens again.

  • I know Hologram is having trouble. None of my devices could connect for past 7 hours.

  • Yep – I had a problem with my library.  All is good now. Sorry for the fire drill.

  • Sara noted above that she re-wrote TinyGsm – so I decided it was a good time to update all my code with new libraries.  Trouble is, I can’t get TinyGSM with templates from EnviroDIY GitHub to compile on the Arduino IDE (I’m not using PlatformIO).  I’m sure I’m making a simple mistake or compiler option but can’t figure it out being a novice C++ p…[Read more]

  • More news:

    1. The cutting and soldering of the Mayfly and XBeee adapter mentioned above works great!  I can now programmatically reset the modem if it gets into a non-responsive state.  I’m thinking of ditching my Sleep Mode code and instead doing a Shutdown(SD) and power off via A5 between communications. It may be less error prone and it does u…

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  • I had something interesting happen to me last week – a brand new XBee  (with brand new firmware 11415) + brand new SIM card would NOT connect to the tower for days.  In desperation, I changed the Carrier Profile from 0 to 2 (AT&T) and it connected immediately.  After that, I changed the CP back to 0 and it connects fine.

    All of my inst…[Read more]

  • From time to time, some of my XBee radios in the field get into a state that won’t communicate.  Even though I can successfully execute AT commands nothing I’ve found but a power recycle will get it out of that state and communicating again.  One thing that can cause the problem is a power brownout but there are other causes that I don’t underst…[Read more]

  • From what I read in the documentation, the following sketch should include these libraries for concurrent SDI-12 and RTC support.

    #include <SDI12_PCINT3.h>
    void setup() {}
    void loop() {}

    But I get compile error:

    librariesEnviroDIY_PCInt_PCINT0Sodaq_PcInt_PCINT0.cpp.o (symbol from plugin): In function…[Read more]

  • Thanks, Shannon, for your response, clarifications and tremendous work with the Mayfly. Addressing your questions:

    I’m powering the CS451 with the same 12v battery that powers the Mayfly from the 12-5v USB converter. The ground (-) of the Mayfly & battery are common. I could not find anywhere in the Campbell Sci specs the voltage level for the…[Read more]

  • Next week I’m deploying several units – Mayfly with XBee using Hologram SIM, logging data from CS451 SDI-12 pressure transducers. They are replacing old 12v systems with Microhard 3G modems and CR300 Dataloggers. The old modems are power hungry and unreliable. The AT&T service is expensive and 3G will go away eventually. The dataloggers have…[Read more]

  • Cal replied to the topic GPRSBee in the forum Mayfly Data Logger 3 years, 7 months ago

    After a few months of successful communication with the DIGI XBee3, I am now starting to get failures with longer and successive Internet messages. Delays between sending messages helps.

    I believe the problem is power related even though I’ve made the solder jumper. Once the XBee fails to transmit, I have to power-cycle it or airplane mode…[Read more]

  • Thanks Sara. I think a cheap 12v to 5v phone charger will work well for me then.
    As for the LiPo battery – I will use a small one. Our transmissions are short and the LiPo will be recharged from the lead-acid battery.

    I have the V0.5b version of the Mayfly – so I could use the 12v input. But I’m a little worried though that the voltage may…[Read more]

  • I’m planning to replace some existing datalogging equipment with the Mayfly and keep some of the existing power equipment.

    Today I have several stations each with Campbell Scientific dataloggers & sensors, standalone modems, solar panels, lead-acid batteries and charging circuits. The equipment is all 12v based. My desire is to pull out the d…[Read more]

  • Cal posted a new activity comment 3 years, 10 months ago

    Neil – there is no solar panel on this setup. We swap the battery with a new charged one after 3 months use.

  • Cal posted a new activity comment 3 years, 10 months ago

    Neil – I saw the spike on my Mayfly for the 2nd time last week. I think I have a different problem than you – and I think my problem is battery related. The spike goes from 4v to 5v then tapers back down over several hours. I can’t imagine any stray electromagnetic field causing that kind of jump for that kind of time span in the middle of…[Read more]

    • Cal – Some thoughts, if you are using the Mayfly’s battery measurement its not actually measuring the LiIon battery voltage. How are you connecting the solar cell and what rating is it?
      If the battery is charging, its taking current and the voltage indication is close to that of the battery – depending on how much solar there is. For the voltage…[Read more]

      • Neil – there is no solar panel on this setup. We swap the battery with a new charged one after 3 months use.

  • Cal replied to the topic GPRSBee in the forum Mayfly Data Logger 3 years, 10 months ago


    When I went to Carrier Profile 2 (at&t) instead of CP 0, my connect time decreased by about 1 minute. Not a huge improvement. I’m hoping my long connect time is due to poor cell signal or bad configuration – and not a modem problem. I’m going to try to travel to a better area this weekend and see if I get connected faster. I’m also…[Read more]

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