[Shannon Hicks]

The two sensor models perform exactly the same.  We’ve used a couple in the field with existing loggers when replacing some old broken Cyclops 7f sensors.  All we did was swap the sensors and redo the calibration and edit the appropriate 2 lines in the code for the voltage measured in the standard and the blank (nanopure water).  The C-FLUOR sensors do come with a calibration voltage on a datasheet in the package, but we prefer to do our own, plus we recalibrate them in the field periodically once deployed.  We use a rhodamine standard we purchased from Turner.   So you can just use the existing ModularSensors Turner Cyclops library.   Keep in mind that the sensors output a 0-5v analog signal, so you’ll need to use a resistor-divider to read them properly with a Mayfly logger.  Our new multipurpose screw terminal board has that option if you add your own resistors and change the solder jumpers on the back of the board.

[Shannon Hicks]

Can you email me the entire .ino sketch that you’re using with the board, and also a clear, in-focus photo of the back of the Mayfly board, and the front of the Mayfly board, with and without the LTEbee attached.

[Shannon Hicks]

Everyone has been out of stock of that particular battery for the past 6 months.  As you said, you can use the Adafruit 6600mAh pack (https://www.digikey.com/en/products/detail/adafruit-industries-llc/353/5054549), or you can use the single-cell 2200mAh cell (https://www.digikey.com/en/products/detail/adafruit-industries-llc/1781/5054543).  As long as the pack is 3.7v nominal and has the correct polarization of the red and black wires on the JST-PH connector, it’ll work.  We recommend using packs from Adafruit or Sparkfun because they always have the right polarity.  Using packs from other sources will usually have the connector pins backwards, which will result in catastrophic damage to the Mayfly board if it gets plugged in.

[Shannon Hicks]

We ordered a couple of these modules and they arrived a few days ago.  I did some testing the past couple days and had only occasional success at sending data to MMW with them.  We’re thinking the code libraries probably need to be tweaked to work with these new modules, but there’s no usable electrical or software documentation for these particular modules from Digi at this time, so we’ve got limited info to work with.  We also used one of our standard Hologram SIM cards and the module would only connect to either T-Mobile or AT&T, so you might need to have a different carrier’s SIM card if you want to get these to work with Verizon.

[Shannon Hicks]

You can also try disconnecting the solar panel for a few days since you’ve got a fully-charged battery on it.  Then that’ll tell you if there’s any correlation between the sensor noise and charging activity.  On a few rare occasions, a failing solar panel ended up generating noise on CTD sensor data.

[Shannon Hicks]

You can also try disconnecting the solar panel for a few days since you’ve got a fully-charged battery on it.  Then that’ll tell you if there’s any correlation between the sensor noise and charging activity.  On a few rare occasions, a failing solar panel ended up generating noise on CTD sensor data.

[Shannon Hicks]

That’s a good find.  We haven’t tried one of those with the Mayfly boards yet, but we’ll have to buy one and see what all might be needed to get it to work properly.  Previous Digi boards required our now-discontinued bee adapter board to change the pin assignments and power supply options in order to work with the Mayfly v0.5 boards.   But the latest Mayfly boards give you the ability to change bee header pins and power settings by adjusting various solder jumpers on the back of the Mayfly.  Similar adjustments to the sketch would be needed as well to make sure everything matched up properly.  But we’ll order a few of those Digi modules and do some testing and if it all looks good, we’ll add an example sketch to the library.

[Shannon Hicks]

Have you been to the station to clean the sensor lately?  Also, I’d recommend replacing the logger’s battery with a fully-charged one.  Sometimes when those battery packs are starting to fail (from corrosion on the terminals under the plastic wrapper) they will generate noise which can sometimes affect the sensor readings.

[Shannon Hicks]

No, the Mayfly datalogger doesn’t know if any data is missing from the website, it just tries to send it every 5, 10, or 15 minutes (or whatever interval it is programmed for).  If the data doesn’t get to the website database, the logger won’t know, and doesn’t send any old data to fill in the gaps. You’ll need to visit the station and manually retrieve the onboard memory card to see what was recorded when the station wasn’t transmitting.  That visit also will give you a chance to clean the sensor and assess whatever physical problem might be causing the data outages.  My first guess would be a malfunctioning battery pack, so if you’ve got a spare fully-charged pack, swap that out when you swap out the memory card.  Then check the datafile to see what the battery voltage and cell signal strength are during the samples that weren’t transmitted.  You can also manually upload the datafile to MonitorMyWatershed and it will auto-fill in missing gaps.

[Shannon Hicks]

It’s probably easiest if you email me your code so I can check it.  We used 8 of those sensors for 2 years in a continuous deployment and didn’t have any drift or loss of calibration, so I don’t think there’s anything else you need to do with it.  If you’ve got another type of calibrated turbidity sensor or a turbidity standard, you could do a comparison to see if you’re getting similar results.

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