[Shannon Hicks]

The Sodaq_DS3231 library should work with the current Mayfly boards.  Here’s an example from a few years ago that does basic microSD card logging of the onboard sensors and doesn’t rely on ModularSensors:  https://github.com/EnviroDIY/EnviroDIY_Mayfly_Logger/blob/master/examples/mayfly1_TempHumidLight_simpleLogger/mayfly1_TempHumidLight_simpleLogger.ino

[Shannon Hicks]

It sounds like you don’t have all the correct library files installed in your Arduino/libraries folder.  How many sub-folders do you have in that directory on your computer?  When did you last download the ModularSensors library dependency files?

[Shannon Hicks]

That sounds like there’s probably an error in your code that is causing one or more missing functions calls to give an error when compiling.  Have you tried compiling the example sketch exactly as it’s written on that github page I linked above, with no edits at all?  If you’re successful in compiling that example, then compare your edited sketch to the example line-by-line and see what’s causing the error.

[Shannon Hicks]

Section 6 of the EnviroDIY Monitoring Station Manual has instructions and photos related to building the station you have.  Section 6.3 in particular discusses the Hydros 21 CTD sensor that you’re having trouble with.  I’m attaching a screenshot of that section of the manual.  You can see in the photos how the sensor cable has a 3.5mm stereo headphone plug on the end of it.  EnviroDIY makes and sells the 3.5mm-to-Grove adapter board that lets you connect the sensor to the Mayfly Data Logger’s Grove jacks.  Sometimes those stereo jacks get a little corroded inside if a station has been deployed for many years, especially if there’s excess humidity in the enclosure.  So when there’s intermittent data or no data from a sensor, we recommend unplugging the sensor from the headphone jack, then reconnecting it, making sure it’s fully seated in the jack as shown in the photos.  It’s also good to disconnect and reconnect the Grove cable from the Mayfly board to make sure that connection is good too.  If that doesn’t fix your issue, then the next step is to replace the headphone jack, which is available in our Shop.

If there’s still no data from the sensor after making sure the physical connection is good, then it’s likely the sensor died or has a break in one or more wires somewhere along the cable length.  This usually means the sensor needs to be replaced since it’s difficult to repair the cable, especially if the internal air pressure vent tube has been damaged as well.  To test whether the sensor is really bad, we recommend getting one of the ZSC bluetooth modules from Meter Group (follow the link on the manual webpage), which allows you to see live data directly from the CTD sensor.  If that confirms that the sensor has failed, then you’ll need to order a replacement sensor from Meter Group.  Once you get a new CTD sensor, you will need to use the ZSC module to configure the sensor with the right SDI-12 channel address.  The sensors are shipped from the factory at channel zero, but you need to change it to channel 1 in order for the sensor to work with your Mayfly board.  Since your group maintains multiple monitoring stations, all with CTD sensors, having a ZSC module is a really good tool for troubleshooting and maintaining your stations.

Your station also has been having intermittent transmission issues for the past couple months, indicating that there’s a dead battery issue.  Looking at the time series graph (screenshot attached), you can see that your battery voltage started dropping at the same time the CTD sensor data disappeared.  This is either because the station is staying on longer each measurement cycle in order to retry the connection to the sensor in hopes of getting valid data, or the sensor has failed electrically and is drawing unusually high current during sample periods.  Either way, your battery should be replaced with a new, fully-charged one.  I think your group has spare batteries and chargers, but if not, there’s a full discussion of options and links for purchasing from different vendors on the Battery options for EnviroDIY Mayfly Data Logger page.

Attachments:

1. 

   msac2s_tsv.png
   

2. 

   manual_6p3.png
   

[Shannon Hicks]

What sketch are you running?  The debug statements above are mentioning Digi Xbee module, but your photo shows a Simcom SIM7080 module.  The code for a Digi Xbee modem is not compatible with the Simcom module shown in the photo.

If you’re trying to use the configuration shown in the photo, along with a Hyrdos 21 CTD sensor (as indicated in your code above) then you should be using the example sketch we wrote for this exact configuration:  https://github.com/EnviroDIY/ModularSensors/tree/master/examples/DRWI_Mayfly1

[Shannon Hicks]

What is the control board that you’re using between the Mayfly and the pumps?  Something with some relays?  How is it connected to the Mayfly?  Via Grove cables or the 2×10 header pins?  Can you post some photos of the setup, or maybe a wiring diagram?

[Shannon Hicks]

Did you make the changes to the Mayfly’s solder jumpers and sketch?  There’s a discussion about the necessary changes here:  https://www.envirodiy.org/topic/digi-ltebee-on-mayfly-v1-x/

[Shannon Hicks]

Digi brand boards won’t work with the Mayfly v0.5 boards unless you also use one of the special adapter boards we used to make and sell, but we haven’t used those since 2020 when the Mayfly v1.0 boards came out.  The 1.0 and 1.1 Mayfly boards eliminate the need for an adapter between the Digi board and the Mayfly, but you still have to make changes to certain solder jumpers on the bottom of the Mayfly board, and also make changes to the sample Arduino sketch since they’re mostly all written for the EnviroDIY sim7080 LTE board.  Which Mayfly version are you trying to use with your Digi board?

[Shannon Hicks]

I know several people who have told me they’ve deployed Mayfly loggers in sensor stations on buoys or some other sort of floating platform, but I don’t think any of them have shared their methods or photos of their equipment.  We’ve done several ourselves over the past few years, and I’m attaching a photo of one of our most recent versions.  The logger box has a 2W solar panel mounted flat on the lid of the enclosure, a cell modem for data transmission, it all rests on a little plastic platform mounted to a rigid foam life-ring, and the 4 sensors are suspended in the water below the station.  We anchor it to the shore from above with a line on a pulley system so we can easily bring it over to the shore for cleaning or maintenance.  If you’re going to be anchoring it with a line to the lake bottom, then my only concern would be that the sensors might get tangled in the anchor line depending on how deep you’ve suspended your sensors, how much slack you have on the anchor line, and what sort of wind conditions or movement the station might make over time.  What sensors are you thinking of putting on the station?

Attachments:

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   floating_station_bernasconi.jpg
   

[Shannon Hicks]

There are descriptions of the battery and solar panel options in section 6 of the Monitoring Station Manual knowledge base, and also on this page about Mayfly Logger Battery Options.

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