Data Logger Developers

  • Hello,
    In order to charge the battery of the Mayfly with a solar panel, do I need to put instructions in the code?
    If so were do I find that line of code?
    In case the mayfly doesn’t need any code to read the solar panel, Why isn’t my mayfly getting charged from the solar panel?
    Thanks in advance,
    Luis Andres Guillen

    • No, no additional code is needed for a solar panel to charge the Mayfly battery. What kind of panel are you using, and what type of battery? If you connect a 6v solar panel with a standard JST-style connector to the “SOLAR” port of the Mayfly, it will charge any single 3.7v LiPo battery connected to the “LIPO BATT” port.

      If you have really…[Read more]

      • Thanks for the prompt answer.
        The panel should be from the starters kit from last year, around the Cuashi meeting. I got it from Nicolas.
        I have the connected it that way. Panel to SOLAR and Battery to LIPO BATT JP2
        The letters are KE3J.

    • If you have a battery connected to the LiPo jack, you should see a yellow LED light up next to the battery jack whenever the solar panel is connect and placed in the sun. You should also see the yellow LED if you have a battery connected and you plug a USB cable into the Mayfly, because the charging circuitry can be powered by either a solar…[Read more]

    • Thank you! I had not noticed the yellow led, that is really helpful to know if it is charging. I went through the connections again and it seems to be charging now! Thanks again!

  • Hello,
    Does anyone have experience in connecting a Campbell Scientific CS616 Water Content Reflectometer to the Mayfly?
    In that case how do I go about it? How much power would I need to sample every 30 minutes?
    I am new to this field, so all comments and direction are really welcome.
    Thanks,
    Luis Andres Guillen

    • I haven’t used one of those before, but it outputs a square wave that’s frequency is proportional to the soil moisture, so your logger would have to do some frequency measurements and then convert that to VWC using a formula. But that particular sensor has a low (0.7v) output, so you’d probably want to use the CS625 sensor, which is the same as…[Read more]

      • Thank you very much for the information Shannon. I have already several of those sensors, so I wanted to put them into use. I I’ll check which type of water content they have found in the site to see if that is an appropriate sensor. Thanks!

  • JimMoore posted an update in the group Group logo of Data Logger DevelopersData Logger Developers 4 months, 3 weeks ago

    Thanks, I think I will go with the blob on the battery.

  • JimMoore posted an update in the group Group logo of Data Logger DevelopersData Logger Developers 4 months, 3 weeks ago

    I tried out the “Sleeping Mayfly logger example” and after I had installed the needed libraries and the sketch compiled I got an “SD card missing” error. The problem was that SD_SS_PIN in the example was 11. Worked fine when I changed it to 12. Is this the case for all Mayfly boards or was there a revision somewhere?
    While playing with this co…[Read more]

    • The SD select pin on all versions of the Mayfly is pin 12. There was an error in that example, so I just fixed it. As for your RTC losing time, I think you have a board that was sold before I started modifying all of the boards with a small blob of solder on the board under the battery holder. If you have a fine tip solder iron, you can do…[Read more]

  • Hi all, I’m pretty new to data logger development but have certainly gotten my feet wet. A project I am currently involved in requires measuring tiny changes in tree stem growth. So tiny, in fact, I believe I have to deal with signal noise from my power source/14 bit ADC. I know I can apply some statistical methods (ie. averaging with…[Read more]

    • Hey thanks for posting. Interesting issue.
      Noise in circuits is well studied and a deeeeeep issue. In circuits there are two types of noise to manage, faster than 1hz and then probably your main concern and more challenging less that 1Hz . Filtering out noise is useful at higher frequencies where low frequency noise is not an issue.
      Managing…[Read more]

      • Wow some great info. Thank you very much and I will check out the your blog as it seems this career path will be heavily involved in these kinds of problems. The design is straight forward, a Li-Polymer battery, arduino pro mini with the ADS1115, xbee series 2 and a Midori Precisions linear sensor…essential a variable resistor up to 1K. Trees…[Read more]

    • Hey Jeremy,
      Interesting project there – I’ve wondered about the effect on the trees when they are really transpiring in a heat wave,
      and also what the delay was between heat peak for transpiration, and pulling the water from the ground, and stream.
      So looking to measure 6microns, or 0.006mm across the LP-10F travel of 10.0 mm
      I’m guess maybe you…[Read more]

      • Those are some great questions. Tree water/soil/atmospheric relations is where a lot of this work is pointed. Some species, like the Picea abies, can swell up to 0.006 mm in a 24 hour period, others less so, so I’m looking to detect changes within the 0.000-0.006mm range.

        Generally speaking, would one start with identifying noise at the power…[Read more]

        • I think you have to look at all the noise sources with the level of measreument that you are looking at. So broadly for a 0.006mm range, you want some resolution in it, which defines what exactly is your 0. That in turn will translate to the noise floor that you need to exceed. So so you could use a scale of 16 – then you need to be able to…[Read more]

          • Neil this has been such a great conversation. Thank you.

            I don’t understand the scale of 16. Could you elaborate or point me to a reference. I’m having a hard time googling that one. This sensor is a “cheaper” version of one that is in the field being used exactly for this purpose. That sensor has a temp. coefficient of +-400 ppm/K. This seems to…[Read more]

    • Hi Jeremy
      My reference to 16 was that for a total change of 0.006mm its going to be broken down to a scale, and if you choose 1/16 (as its digital) then for 0.006mm/16 you would have a target of 0.000375 mm – which is very small.
      Now looking at the LP-10F spec – which with a total travel of 10mm is better than 20mm for measuring something very s…[Read more]

      • Just came across a devices that maybe could make small distance measurements
        Piezoelectric film – the problem might be calibrating it.
        That is it might be able to show a change in trunk diameter based on stress applied to the film, but how easy would it be to translate to metric mm?
        Also it doesn’t contain a temperature dependency…[Read more]

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