Shannon Hicks

You are correct, if you’re using the USB jack to power a v1.0 or v1.1 Mayfly using a 12v source, then there’s no way to interface the Mayfly with a PC for programming or viewing serial output.  However, all Mayfly boards include an FTDI jack that allows you to connect a variety of FTDI cables or adapters in order to communicate with the board in…[Read more]

It’s still in the prototype and testing phase, but the good news is the the chips that were unavailable for the past 18 months are finally available again.  If you or anyone else have specific RS485 sensors that you’re hoping to use, it would be helpful if you email me at mayfly@envirodiy.org with your sensor model information so we can make sure…[Read more]

The only differences between the v1.1 revA and revB are this:

The ICSP jack was a 2×3, 0.5″ pitch male pin header on Mayfly v1.1 revA.
The ICSP jack is now uses Tag-Connect pads for use with Pogo pins for ICSP programming for the Mayfly v1.1 revB.

And with the revA boards, there was a circuit design change after manufacturing that required me to…[Read more]

If you’ve got 4 heated sensors that require constant 12 volts, then I don’t think the Mayfly and the standard “battery/solar panel combo” is going to be sufficient.  It would be a struggle for the Mayfly to supply the necessary continuous 100ma at 12v for the heaters, in addition to powering the various sensors intermittently.  You could have a s…[Read more]

Sensors with heaters are another big challenge, especially if they run continuously.  Are the heaters powered all the time, or only when taking a sample?   Do they require 12v to operate, or was that spec just listing the power draw at 12v?

You can do some basic battery life calculations on this handy website: https://oregonembedded.com/batterycalc.htm

Standard practice is that when the Mayfly board goes to sleep in between measurements, it turns off all power supplied to the sensors and radio module.  So the power consumed when sleeping is just the bare minimum to keep the Mayfly in sleep mode, which is usually a little less than 1 milliamp.  There are ways to make it use even less in sleep m…[Read more]

It appears that the Hologram service interruption has been fixed and almost all of the cellular stations on Monitor My Watershed have returned to normal operation.  If any stations don’t rejoin the network by later today, it might require a field visit to cycle the power or possibly replace the battery.

I’m not sure what the Mayfly Data Logger Pro is.  Do you mean the program (or sketch) used to configure the board?  If you’re using one of the provided sketches we publish on Github, there’s a couple lines in each sketch that looks like this:

// Logger ID, also becomes the prefix for the name of the data file on SD card
const char* LoggerID = "…

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There’s a link to the schematic on the item page along with a link to an example sketch on Github.

The CTD sensor you have is a digital output sensor, meaning all of the measurement happens onboard the sensor and it outputs a string of 3 numbers, all the Mayfly logger board is doing is capturing those numbers and storing them.  If there was a problem with the Mayfly board, then you wouldn’t get the numbers at all, and there’s no calibration or…[Read more]

Reminder quote from the first post of this thread:   If you’ve got a basic question such as what are the board’s features or how it differs from previous versions, this is the place to ask.  If you’ve got a more complicated question or issue, then it is probably best to start your own thread.  The goal of this thread is to be a great informati…[Read more]

The analog reference voltage (AREF) pin of the ATmega1284P is broken out to the left-hand 2×10 header if you wanted to apply a voltage other than (and less than) 3.3v.  If you leave it floating and don’t specify the AREF in your code, then it’ll use the default 10-bit setting for any regular analog reading like you’ll find in most code…[Read more]

LTEbees should be back in stock later this week in the EnviroDIY shop and in a week or two on Amazon.  The big order we placed from our manufacturer back in March had some production delays but is supposed to be delivered this week.  The RS485 adapter is still not ready for release, the original design relied on the 12v boost circuitry of the M…[Read more]

The Bee socket of the Mayfly board isn’t powered continuously by default, so in your code examples above, it appears that you’re not turning them on.  If you study the schematic for whichever hardware version of the Mayfly you have, you’ll see that you either have to activate the power to the bee socket’s regulator by setting Mayfly pin D18 high…[Read more]

The ADC example I linked above from Sparkfun applies only to the onboard 10-bit ADC of the ATmega1284 processor.  For the ADS1115 auxiliary ADC on the Mayfly board, the formula on the Sparkfun page does not apply, because the ADS1115 is a dedicated ADC chip and works differently.  The operational specs of the chip are outlined in the TI d…[Read more]

The calculation for the conversion of analog bits to voltage depends on the operational voltage of the system (3.3v in our case) and the resolution of the ADC.  You can see an example calculation (and more importantly, the formula used) for a 10-bit Arduino here:  https://learn.sparkfun.com/tutorials/analog-to-digital-conversion/all

The ATmega1284P processor of the Mayfly is similar to other basic Arduino boards with the 324P processor in that it has an internal 10-bit Analog-to-Digital converter (ADC).  There are 8 ADC pins on the 1284P, so these pins can be used to read analog voltages, however at a pretty coarse resolution (1024 bits over the 3.3v sample range).  But t…[Read more]

There’s nothing to unsolder.  Solder Jumper SJ25 has 2 small pads.  By default, they are separated and not connected at all, and that makes the on-board boost circuitry output 12 volts.  By putting a solder blob on SJ25 and connecting the 2 pads, you add some extra resistance to the circuitry that controls the voltage and it’ll output 9 volts in…[Read more]

Have you tried disconnecting one sensor at a time and seeing how the other one performs?  We’ve found that sometimes when one sensors fails or “goes bad”, it can cause erratic readings or performance of any other sensor that’s also connected.  By unplugging each sensor independently, it’s usually easy to isolate which sensor was the actual c…[Read more]