Welcome to EnviroDIY, a community for do-it-yourself environmental science and monitoring. EnviroDIY is part of WikiWatershed, an initiative of Stroud Water Research Center designed to help people advance knowledge and stewardship of fresh water.
New to EnviroDIY? Start here


  • Luis Andres Guillen posted an update in the group Data Logger Developers 7 years, 1 months ago

    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 good eyesight, or have a magnifying glass handy, can you tell me what letters are printed on the tiny black 5-pin chip (labeled U1) that’s mounted on the Mayfly between the SOLAR and LIPO BATT. sockets

      • 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 panel or the USB cable. You’ll see this even if the Mayfly board power switched is turned off because the battery is charged anytime there’s solar or USB power applied to the board. If you have more than one Mayfly board, verify that the panel and battery work with other boards. If you’ve got more than one battery and/or panel, switch those around too. You should be able to narrow down whether it’s the board, panel, or battery that is consistently causing the error.

    • 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!