[Shannon Hicks]

Yes, the server was restarted this morning and service returned to normal, however all stations will be missing about 11 hours of data from earlier today.

[Shannon Hicks]

Yes, we’re aware of if and the data team has been notified.  No estimate on when it will be back up yet.

[Shannon Hicks]

There was a very small adjustment made several months ago to the delay time between commands to make communication with the Meter Group Gen 2 CTD sensor a little more reliable.  I don’t remember the exact date, but the latest release of ModularSensors definitely works with them.

[Shannon Hicks]

I’m not familiar with that module, but the specs say that its default baud rate is 115200, so you should set your “modemBaud” rate in the sketch to match that, so something like:

const int32_t modemBaud = 115200;

1	const int32_t modemBaud   = 115200;

Was that the value you changed in your sketch?  Because it’s set at 9600 in the example you attached.  Have you successfully communicated with the LoRa module by itself, outside of the Mayfly, by using just a basic bee carrier board?

[Shannon Hicks]

The current estimate is that we’ll receive a big shipment in about a month, so early August we’ll be able to restock the shop and Amazon.  The worsening electronics supply shortage caused me to have to make some changes to the Mayfly design based on component availability, and that delayed the fabrication of new boards until we could fully test everything.  I’ll post more information about the upcoming changes and improvements to the board and our new accessories in a few weeks.

[Shannon Hicks]

The entire electronics industry is facing growing supply issues that started last year.  I’ve been aware of the issue since early this year and started planning accordingly, so we shouldn’t have any supply issues with our custom EnviroDIY products.  But industry experts and suppliers are saying that components and products from companies like Digi will be difficult or impossible to find until next year sometime.  This is going to cause major supply shortages and price increases in every electronic device that needs to be built.  If you think you’ll need anything in the next year, I’d recommend you buy them now while you still can.  In the meantime, we’re awaiting a new production order of Mayfly boards and accessories, including some new items.  I’ll make a full blog post in a few weeks when we’re ready to release everything since these forum threads can sometimes get buried, and I think EnviroDIY members will be interested in all the new updates.

[Shannon Hicks]

I successfully used that sensor with a Mayfly v0.5 board with no problem.  If you’re powering the sensor with a separate 12v battery, do the Mayfly and the 12v battery share a common ground?  The white wire from the sensor is the SDI-12 data line, which should go to pin 7 , as you stated in Line 93.  It’s fine to use a separate battery to provide the 12v power to the sensor (red wire), but you need to make sure the Ground pin of the Mayfly is connected to that external battery, and the ground line of the sensor (black) is connected to the external battery as well.  I assume you used the sensor’s two RS485 wires (green & blue) to connect to some sort of modbus-to-PC adapter so you could use their software to change the SDI-12 channel number?  For future reference, you can use the Mayfly to change that channel number using the example “b_address_change” sketch included in our SDI-12 library.  Once you’ve deployed your sensor and don’t need to access the RS485 wires anymore, make sure you cover the bare ends of the green and blue wire and don’t let them touch anything on the Mayfly board or other pins in your logger enclosure.

I would also suggest removing line 172, because it’s going to reprogram the RTC time every time the board is turned on or restarted to whatever time you’re written in line 34.  If you’ve got a CR1220 coin cell battery in the Mayfly’s battery holder, there’s no reason to set the clock more than once.  It’s best to set the clock in a sketch all by itself, then verify that it’s synchronized, then upload any other sketch you want and the clock will keep the correct time for several years, until either the CR1220 dies or is removed.

[Shannon Hicks]

I’d have to see the rest of your sketch to know what you’re trying to accomplish with the 5v output.  If you put the CTD sensor on the D4-5 jack, and move the jumper to constant 3.3v, then the SDI12 power pin part of the code doesn’t really matter, but that kind of stuff gets declared early in sketch, usually in the setup function.  The bigger problem will be if you’re trying to keep a 5v output line powered after you take a reading and the logger goes to sleep, because normally the logger shuts down all the pins before going to sleep between readings.

[Shannon Hicks]

The Hydros-21 sensor already does internal temperature compensation of the depth data, so you shouldn’t have to provide your own compensation.  The sensor outputs the depth readings in millimeters of water above the sensor, so you don’t even have access to the raw pressure readings like you might with a basic pressure transducer, so you’d have to do any corrections on the sensor’s already-corrected depth output.  You could record temperature with a separate external temperature sensor, but we’ve found that the temperature reported by the CTD sensor is accurate, except in cases of extreme rapid temperature changes, in which case it takes anywhere from 5 to 15 minutes for the CTD temperature to match a DS18b20 sensor in the same water (like when we poured refrigerated water on a room-temperature sensor).  The new Generation 2 Hydros-12 sensor had a quicker response to the temperature change than the old generation.

We do see a variability of about 5mm to 10mm in the depth reading if the sensor is in a constant depth of water but the water temperature changes from about 10C to 30C over the course of a day.  However, that variability depends on the individual sensor, since we tested 10 different sensors all from the same production lot and found that some were more constant across temperature changes than others.  So if micro-scale variations in depth or conductivity matter to your experiment, I’d recommend doing some controlled testing with your sensor in a lab environment where you can change the temperature of the water while recording sensor output to get a profile of how your individual sensor responds to changing temperatures.  And since the conductivity readings of the Hydros-21 sensors are specific conductivity, then temperature sensitivity affects those readings as well, so check your conductivity readings over a range of temperatures as well.  Some of the sensors are more accurate than others, but all of them have been within the design specs of the manufacturer’s stated accuracy levels, but it’s important to find out how precise your sensor is since it varies for each one.

[Shannon Hicks]

What’s the duration of the 5v signal you want to generate?  And how much current does the 5v actuator draw?  Pin D22 controls the switched 3.3v and 5v outputs together, so there’s no way to separate the two.  However, a Hydros-21 CTD sensor uses very little current when it’s constantly powered, so you could plug the CTD into the D4-5 Grove jack, then move the jumper switch for the D4-5 jack over to the “3.3v” setting instead of the “3.3v Switched” setting, so the sensor would be constantly powered.  Be sure to change the CTD channel number in your sketch to “5” instead of “7”.  Your CTD sensor will now be constantly powered, but will only use measureable amounts of power when you send the SDI-12 command to take a reading, which most sketched do once every 5 minutes.  Then you could put the jumper on the D10-11 jack set to “5v switched” and when you turn on D22, the Grove jack’s Vcc pin will get 5 volts.  This would only work if you have no other sensors on the D22 line that you want to control.

The other option would be to use a Grove relay board, like one of the ones from here: https://wiki.seeedstudio.com/Seeed_Relay_Page/ (only the ones with 3v excitation though) which would allow you to control a relay that’s capable of switching high current or high voltage signals.  But you’d still have to figure out where you’re getting the 5v signal, which again depends on how much current you’re trying to control and for how long.

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