[Shannon Hicks]

If you’re using an external FTDI or CP2102 interface board to program your Mayfly via the Mayfly’s FTDI socket, then the Mayfly dipswitch labeled USB should be turned off before connecting the external interface to the Mayfly, and it should stay off the entire time.

What version of the Arduino IDE are you using?  From your screenshot, it looks like you might be using one of the newer versions.  On our software instructions page here:  https://www.envirodiy.org/mayfly/software/    we recommend that you use the Legacy v1.8.x version since there are some quirks about the newer v2.0 and web-based Arduino IDE’s that can cause issues with the Mayfly.

When you plug your CP2102 Friend into your computer’s USB port, what does Windows Device Manager say?  Does a “Silicon Labs CP210x USB to UART Bridge (COMx)” show up under the “Ports (COM & LPT)” list, or is it shown under an Unknown Device tab with a yellow triangle?

[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 the event of a broken or otherwise occupied USB jack.

Check out this post I wrote last year describing how to connect a small board called the Adafruit CP2104 Friend to a Mayfly:  https://www.envirodiy.org/topic/pc-and-mac-unable-to-communicate-with-mayfly-ver-0-5b/#post-16736

Be sure to scroll down to the bottom of that thread to see the photo I posted showing how you’ll need to solder some right-angle header pins to the end of the Adafruit board in order to plug it into the Mayfly.  Adafruit has since updated and renamed the board the CP2102 Friend but it can be used the same way.

If you don’t want to have to solder something, then you can purchase the older FTDI Friend model that is shipped with long double-ended male pins to let you connect it to the Mayfly with no soldering required.  I wrote about it here:  https://www.envirodiy.org/topic/com-ports-not-connecting-to-logger/#post-15418

The older FTDI model uses a different chip than what is used on the newer Mayfly boards, so you might have to install some drivers if you use that one, I mention this in that post along with a photo of the correct way to connect the board to a Mayfly.  You could also use an FTDI cable, though I don’t know if it comes with the long pin headers so you might have to buy those separately.

Another thing to note, there is a CP2102 USB interface chip built into every Mayfly v1.0 or v1.1.  That’s what allows you to communicate with a PC via the USB jack.  If you connect a separate computer interface board via the FTDI jack, like any of the boards mentioned above, it’s a good idea to disable the Mayfly’s onboard CP2102 chip to avoid hardware conflicts and errors when uploading a sketch.  The small brown block next to the Mayfly’s power switch contains 2 small dip switches.  Here’s a description of them from the Hardware Details page:

Power LEDs and DIP switches:  LEDs indicate board power (green) and USB power (orange).  Useful for easily seeing if the board is on and if USB power is connected.  Green LED will be lit anytime the board has power and the power switch is in the ON position.  Orange LED will be lit anytime power is being supplied through the USB or FTDI connectors.  If Mayfly board is deployed in a sleeping logger station, it is recommended to set both DIP switches to the OFF position in order to save battery power.  Use a small pointed object to gently slide the small white squares of the DIP switch either to the ON or OFF positions.

So if you’re powering your Mayfly with the USB jack, you’ll be wasting a lot of power keeping the LEDs on and also powering the onboard USB converter chip.  I would recommend turning both switches to OFF during your deployment, but you’ll need to remember to turn the USB switch back on if you ever want to reprogram the Mayfly via it’s onboard USB jack in the future.  Here’s something I wrote on the technical discussion thread last year:

The dipswitches are mainly there to let people know their board is working during initial testing or desktop deployments.  Anytime a board is deployed in the field as a “sleeping” station, power savings are important during the sleep period.  So I put the dipswitches on the new versions of the Mayfly to allow people to deactivated the LEDs.  The dipswitch for the green LED only cuts power to the green LED and nothing else, but it will save you about 2 mA.  The orange LED is only on if power is being supplied through the USB jack, like when connected to a computer or when powering from the USB jack like what that converter will do.  Whenever the USB jack is powered and the USB dipswitch is on, the LED is on plus the USB converter chip, which draws some not-insignificant power, so turning off the USB dipswitch will save power and prevent the USB converter from being on constantly.  However, you’ll just have to remember to turn that dipswitch on again in the future if you ever decide to reprogram that Mayfly or want to connect to the Serial Monitor to see some output.

[Shannon Hicks]

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 we produce an adapter that works with a many different sensors as possible.

[Shannon Hicks]

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 hand-solder a small jumper wire to bypass solder jumper SJ26.  It is noted on the schematic.  That change was incorporated into the production run of the revB boards, so electrically, revA and revB boards are the same, except there’s a physical wire on revA and a board trace on revB.  There’s also a dab of conformal coating covering SJ26 on all revA boards to prevent it from being used.  This is noted on the Jumper Settings page if you scroll about halfway down.

As for the schematics, they are available for all version numbers via the links on the Hardware page you linked.  Click on the name of the desired schematic version, it’ll take you to a preview page.  The schematic shown on that page can appear fuzzy or low-res depending on your web browser and monitor size/resolution.  But simply click on that image of the schematic and you’ll be taken to the actual pdf file which is a high-res 11×17 pdf that can be printed or zoomed in on, allowing you to see all the details.

[Shannon Hicks]

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 separate 12v battery with it’s own 12v solar panel and charge controller to power the sensor heaters, and then use a 12v-to-5v converter to power the Mayfly via the USB jack.  Then you wouldn’t have to worry about the smaller Mayfly battery and solar panel, and the bigger battery/panel combination should be sufficient for powering your whole setup.

[Shannon Hicks]

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

[Shannon Hicks]

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 mode, but it’s usually not necessary since the overwhelming majority of the power used is during the sensor sampling and radio transmitting time.  Power-hungry sensors with motorized wipers or large current draw, and radios that need long connection times are the most challenging peripherals to use, but 3 soil moisture sensors and an unltrasonic sensor will use very little power when sampling, so they won’t stress a 4400mAh battery at all when matched with a decent solar panel like the 3.5w or 5w panels we usually recommend.  I don’t know what Xbee module you’re using since they make wifi, cellular, and RF modules, but your transmit time and duty cycle will determine the overall power usage.

[Shannon Hicks]

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.

[Shannon Hicks]

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 = "XXXXX";

1 2	// Logger ID, also becomes the prefix for the name of the data file on SD card const char* LoggerID = "XXXXX";

The Logger ID is just an alphanumeric designator that you can use to name your station to help with record-keeping and organization, because the logger ID becomes the prefix for the data file that is written to the Mayfly’s microSD card.   All Mayfly data card files are named using the Logger ID and the date the file was started.  So a Mayfly with the logger ID of “BLUE” would have a file named “BLUE_2023-07-20” if the logger was started today.

If you look through the EnviroDIY Monitoring Station Manual, you’ll see examples and further descriptions of the file operations of the Mayfly.  The manual was originally written for our partners in the DRWI monitoring program, and those stations were all built and programmed by me, and we used an internally-generated logger ID system starting with the letters SL.  Other users are free to choose any name or number they want.

In general, it’s good to put the stream name or some other helpful info in your logger ID (while still keeping it short, and using underscores instead of spaces) because it will make the names of your resulting microSD card datafiles more descriptive.  For example, i might call one “Upstream_JonesCreek”, that way all my data files will begin with that string, because there might be a “Downstream_JonesCreek” station too.  A new data file is created anytime the Mayfly station is rebooted, so if both stations are out collecting data and both get visited today and have their data cards swapped with new blank cards, they will both start recording to data files with today’s date in the filename.  It’s the Logger ID that will make the filenames unique so that when you later copy both of those data files to your PC, they’ll be uniquely named and there won’t be any confusion about where they came from.

Another note, the Logger ID as written in the Arduino sketch of the Mayfly board is not the same as the Site ID of a station on Monitor My Watershed.  That’s a different type of naming convention that is independent of the Mayfly programming.  The string entered for Mayfly Logger ID in your sketch is only used for generating the microSD card filename on the logger.

[Shannon Hicks]

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

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