[Shannon Hicks]

Yes, you can email me at mayfly@envirodiy.org

[Shannon Hicks]

That’s what the data looks like when the CTD sensor gets disconnected from the Mayfly. The turbidity sensor is still being read, and there was no change in turbidity around the time of the data loss. So you can rule out someone stealing the sensors, or that it was damaged during a flood event, since there doesn’t seem to be an event happening. And since it was at 2am, it’s unlikely that someone is there unplugging things. My guess is that a mouse chewed into the cable between the station and the water, or that it’s a random (but really rare) electrical failure of the sensor. Which station is this from? Have you been to the site to check on the condition of the cables?

[Shannon Hicks]

The code we put on your loggers a few months ago needs to be replaced with the newer version because the latest updates account for the addition of Verizon as a carrier, and make a few other tweaks to the basic functions of the station we’ve made since deploying a few dozen LTE stations in the last month and examining their performance. All you need to customize the code is three things: enter your station ID /stream name into the correct part of the code near the beginning (line 47), the UUID information for each station (which Jake will have to get from the MMW site since only the site owner can view those values), and you’ll also need the turbidity sensor calibration information, which is written in the “Notes” field of the two turbidity parameters in each of your stations (these are the values obtained from the calibration sheet that comes from the turbidity sensor manufacturer and is unique to each individual turbidity sensor).

So you have all the info you need to customize the sketch for all of your stations. If you want to email the sketches to me before you write them to the logger so I can check them for accuracy, that might be a good idea. Just zip all the .ino files into one ZIP file. Many email clients won’t let you attach a raw sketch file due to antivirus/security filters, so it’s best to zip them before sending.

[Shannon Hicks]

The Mayfly stations with 4G-LTE modules that we deployed for you earlier this year were all configured to only use AT&T as the provider, but since then we have tweaked the code to allow them to work with either AT&T or Verizon, whichever carrier has the strongest signal at your location. It still uses the same Hologram SIM card, it’s just a configuration that the Mayfly writes to the LTE Bee when you boot up the Mayfly. If you download the latest Modular Sensors libraries (0.23.16) from our Github repo and use an example sketch from that directory, then it will configure the module properly for either cell carrier. If you haven’t programmed a logger with ModularSensors yet, you’ll probably need a bunch of the other libraries as well, so it’s easiest to just grab everything from here: https://github.com/EnviroDIY/Libraries
Follow the instructions in the ReadMe that tells you how to properly download all of the files in the Libraries repo. And if you’re using the Arduino IDE and you already have some of the folders that are contained in the EnviroDIY Libraries repo (which is probably very likely), then you might end up with conflicts due to having multiple copies of similar libraries, so you might have to resolve those. Using something like PlatformIO as your IDE will solve the library conflicts, though it has a pretty steep learning curve if you’re new to programming.

[Shannon Hicks]

Jake, the stations we installed for you a few months ago were programmed with code that set the low voltage threshold at 3.7, which is fine in areas with lots of sun. But since your stations are more shaded, and you’re in a higher latitude, your battery will probably hover around 3.7 most of the time, so lowering your transmission cutoff threshold will keep your station online more reliably. If you look at the code example below, the command on line 370 sets the transmission cutoff voltage at 3.55v, which is probably a good level for you, though you could probably set it to 3.50 and still be fine.

https://github.com/EnviroDIY/ModularSensors/blob/master/examples/DRWI_LTE/DRWI_LTE.ino

You’ll need to update a few other parts in the code to match your individual stations. Like lines 179-191 is where you paste the UUID info from your unique logger station entry on MMW. And change the logger ID on line 47 to your unique logger serial number. And then you need to enter the unique turbidity sensor calibration equation for each station in the appropriate lines 127-129 for low range and 137-139 for high range. You can find that info in the NOTES field of the sensor parameter on the MMW station details.

[Shannon Hicks]

It’s actually a microSD card slot, not a miniSD. And no, we don’t sell the adapter separately due to the complexity and cost of selling one small item on Amazon. I could sell a multi-pack of them on Amazon, but I’m not sure there’s much demand for that, since everyone who has previously wanted an adapter either needed only one or ended up buying the starter kit anyway.

[Shannon Hicks]

There is no built-in antenna on the Xbee LTE module, or any cell module for that matter. I’ve tried a variety of antennas, this is the one we usually use because it’s cheap and fairly rugged and fits easily inside our enclosures: https://www.digikey.com/products/en?keywords=1837-1003

Just use caution with the u.fl connector, it is not designed for frequent connections and disconnections. You should only connect it once and leave it on.

[Shannon Hicks]

The APN for Hologram is now “hologram” (with a lower case h) so you might try changing your code to that. But I have lots of older modules that have been out for years and still use the old konekt APN (this was Hologram’s old name) so I’m not sure if that’s the issue. Do you have an appropriate LTE antenna connected to the CELL jack (and not the 2.4 jack)?

[Shannon Hicks]

Mayfly D22 is not a physical pin on the board, it’s processor pin 22, which means you set it high or low using digitalWrite commands in your sketch, just like you would with pin 8 or 9 to turn the red or green LEDs on or off. If you’re new to Arduino or the Mayfly, you might try working through example sketches or workshop sketches in our Github repo to familiarize yourself with the operation before you connect an expensive sensor like an OBS3 to a Mayfly.

[Shannon Hicks]

Are you referring to the two Grove ports in the lower left corner of the Mayfly? All of the Grove ports (and the Sw3 and Sw5 pins in the headers) are designed to only be powered when you set pin D22 high. This is so that you can turn any external sensors on or off independently from other things on the Mayfly. Setting D22 high turns on the external 3v and 5v regulators, and anytime they are on you’ll see a red LED in the corner of the board light up (LED3).

Also be aware that the maximum incoming voltage that the ADS1115 can read is 3.3v, as determined by the Vcc of the Mayfly. You can buy the OBS3+ in different voltage output options, so if you bought the one with 5v output at full scale, you’ll need to use a voltage divider to protect the Mayfly from seeing anything greater than 3.3v. We always buy the OBS3+ with the 2.5v output option so that the max voltage will never exceed Vcc. And if you do use a voltage divider, make sure to account for that in the formula you use for the ADS1115 to convert bits to volts which and translate into sensor output to match up with the sensor calibration equations provided with each sensor.

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