Shannon Hicks

For the past year we’ve had 8 stations using SDI12 CTD sensors and Yosemitech wipered turbidity sensors together on one prototype Mayfly using the EnviroDIY RS-485 half-shield.  It also works with other generic modbus adapters too. We’ve had no issues with not being able to read the sensors or with dropped readings. I’m attaching the code below…[Read more]

When you changed the SDI12 address of the turbidity sensor to “2”, did you use the same Mayfly board and the  “SDI12/b_address_change” example sketch that comes with our libraries, or did you change the address with a different board or instrument?

The only difference between the Gen 1 and 2 Hydros21 sensors is that the Gen 2 sensors need a little more time to respond to the SDI12 measurement command, which is hardcoded into one line in the MeterHydros21.h file within the ModularSensors library.  If you’re using the most recent version of ModularSensors, then your code will support both…[Read more]

From the sketch, it looks like you’re trying to operate both sensors on the same logger by using a separate data pins for each sensors?  That’s not the correct way to do it because of how the underlying EnviroDIY SDI12 library functions. You should instead put both sensors on the same data line (usually D7).  Each sensor will need its own unique a…[Read more]

The old Campbell OBS3 turbidity sensor was an analog-output sensor that had 2 separate voltage outputs, one 5v power supply wire, and 3 ground wires, which is why I designed the old version of the 6-pin screw terminal board that way, because we primarily used it with the OBS3 sensors and connected it to one of the Aux Analog Grove jacks on the…[Read more]

As Neil mentioned above, the yellow LED that is labeled SOLAR only indicates when a charge current is being applied to a battery, so if a battery if fully charged (~4.2v), the LED will not be on.  The charging circuity of the Mayfly v1.1 boards is configured so that the solar panel provides voltage directly to the Mayfly’s main power regulators…[Read more]

The components on the Mayfly circuit board are rated to withstand the industrial temperature range of -40C to +85C.  Here in Pennsylvania, our loggers don’t normally see that full range during normal deployments, but this summer we frequently reached almost 60C with one of our loggers that is mounted in an open field inside a clear plastic…[Read more]

Mayfly v1.x power usage (with no external sensors attached) and both LED dipswitches off (the brown/white slide switches between the main power switch and the vertical SD card socket) is as follows:

Mayfly current when board is powered and idle: 6.5 mA
Mayfly current when MCU put to sleep and no microSD card in socket: 0.27 mA (or 270 uA)
Mayfly…[Read more]

End device certification for an open source DIY project like this is nearly impossible, since there’s an infinite number of combinations that users can configure their station with various equipment, accessories, antennas, not to mention all the ways they can change the actual code running on the main processor board.  That’s why we try to use…[Read more]

We’ve release several different Mayfly Data Logger hardware versions in the past few years, so I’d need to know which version you’re using.   I’m assuming a v1.0 or 1.1 since you mentioned deactivating the LEDs using the dip switches.   But it also depends on the sampling interval you’re planning to use (time between measurements when the May…[Read more]

The data file on your Mayfly’s memory card contains the UUID information for the original station, so even though you’ve moved the station to a new physical location and created a brand new site on MMW for the new location, the data file still contains the UUID codes that correspond to the original MMW site, and the database is smart enough to…[Read more]

No, the old LTEbee Adapter should not be used with a Mayfly v1.x board.  You simply plug the Digi board directly into the Mayfly v1.x board with no adapter at all.  Make the changes to the jumpers I mentioned above and you’ll enable the white and blue status LEDs that are built into the new Mayfly boards.  The only thing missing is the orange RS…[Read more]

The purpose of the now-discontinued “EnviroDIY LTEbee Adapter” was to allow people to use the Digi brand LTE cellular module with the Mayfly v0.5 boards by doing 3 main thing:  providing sufficient power (current) to the cell module, connecting pin 13 of the Digi board to pin 12 of the Mayfly bee socket, and giving the user some LEDs to show…[Read more]

Onewire sensors like the DS18b20 don’t like to have their bus power cycled on and off.   Back when I last experimented with them (with a different sketch not related to ModularSensors), if you’ve got the sensor connected to the switched power supply, you had to do “DSsensors.begin();” each time the logger woke and powered up the switched power b…[Read more]

The polarity of your battery pack is backwards, which is why your board was damaged.  We mention the caution about battery polarity in multiple places on this website, and also in the EnviroDIY Monitoring Station Manual, and specifically in Section 6.1 (https://www.envirodiy.org/knowledge-base/building-an-envirodiy-monitoring-station/).  I’m a…[Read more]

We’ve installed several stations in tidal areas by attaching the sensor to a custom apparatus mounted to docks or piers.  What kind of sensors are you planning to install?

Yes, the update made to the ModularSensors code in in order to fix Hydros 21 is backwards compatible.  I mentioned it last week in this post: https://www.envirodiy.org/topic/hydros-21-decagon-ctd-reading-error/#post-17066

It seems that in the past year Meter Group made some changes to the amount of time the CTD sensors need to take a…[Read more]

When you’re connected to the Mayfly with your computer, open the Arduino IDE’s Serial Monitor and check the settings of the dropdown box in the lower right hand part of the windows next to the baud rate.  It should be set to “No line ending”.  If you have it set to anything else, you’ll usually get an error when setting the address using that s…[Read more]

Yes, it’s just one line (currently line 107) of the MeterHydros21.h file that contains the most important change, which is this line:  #<span class=”pl-k”>define</span> <span class=”pl-en”>HYDROS21_MEASUREMENT_TIME_MS</span> <span class=”pl-c1″>1000</span>

The previous setting was 500 milliseconds but it turns out the new Gen 2 CTD sensors need…[Read more]

We’ve seen this behavior with some of the new CTD sensors as well.  It seems that when you give it a new address using the b_address_change sketch, the sensor needs to be told the new address more than once in order for it to actually make the change.  Meaning, run the sketch and observe the text on the Serial Monitor.  For a new sensor it will sa…[Read more]