Welcome to EnviroDIY, a community for do-it-yourself environmental science and monitoring. EnviroDIY is part of WikiWatershed, a web toolkit designed to help citizens, conservation practitioners, municipal decision-makers, researchers, educators, and students advance knowledge and stewardship of fresh water. New to EnviroDIY? Start here

EnviroDIY Mayfly Data Logger (Pack of 5)


This is a pack of 5 Mayfly Data Loggers, version 1.1 revB. Single unit sales are available on Amazon.

Important note:  This is the Mayfly v1.1 which is visually the same as the recent v1.0 board but with improved 12v output, but it has many important changes from the older v0.5b boards.  If you are replacing an older Mayfly v0.5b board with a v1.0 or v1.1 board, be sure to thoroughly read the Details and Specs page and verify that it will work in your installation.  Previous hardware may not be compatible, and existing sketches (programs) will likely have to be updated in order to use the Mayfly v1.0 or v1.1.

The Mayfly Data Logger is a powerful, user-programmable microprocessor board that can be easily programmed with several popular IDE software programs like the Arduino IDE. It features the ATmega1284p processor, which is much more powerful than the 328p chip found on most other boards. It has 4 times more flash memory for sketches, 8 times more RAM, and almost twice as many input pins as standard boards.

The Mayfly board can be powered by a 3.7v lithium polymer (lipo) battery (not supplied) or through the USB port. Programming can be done through the USB-C port or via the FTDI header.

You will need a CR1220 button cell lithium battery (not supplied) in order for the RTC to retain the time after the power has been removed. More information and tutorials about the board and kit can be found on the EnviroDIY website.

International orders: The EnviroDIY shop does not ship internationally.

Shipping: The EnviroDIY shop ships your order by US Postal Service Priority Mail. Shipping cost is included in the product price listed.  Please allow 2-3 business days for processing after placing an order.  You will receive an email with the tracking number as soon as your order is shipped.

Payment: The EnviroDIY shop accepts all major credit cards via Paypal; customers do not need a Paypal account and don’t pay any fees.

Backorders: If an item is listed as unavailable, the EnviroDIY shop does not accept backorders. Please check back soon for availability.

Warranty: Stroud Water Research Center warranties products sold to be free of manufacturing defects for 30 days from the postmark shipping date. If your product doesn’t work as expected and you need help troubleshooting, please consider posting questions to EnviroDIY.org/forums. If you are confident in the programming and assembly you’ve done but believe the hardware is defective, please contact mayfly@stroudcenter.org to request a Return Authorization Number. Products should be returned in their original box with the RAN written on the box. Customer is responsible for shipping cost. Following receipt and evaluation, Stroud Water Research Center will either send a replacement product if the original was deemed defective or return the original if it was not defective.

Returns: The EnviroDIY shop will accept return of unused or defective products (see Warranty section for details) for 30 days after the postmark date of shipment. Returns must be authorized and shipped with a Return Authorization Number on the outside of the box; contact mayfly@stroudcenter.org to request an RAN. Returns must be sent in their original shipping box. A $30 restocking fee will be applied to the credit on customer’s payment. Customer is responsible for return shipping to Stroud Water Research Center, ATTN: EnviroDIY, 970 Spencer Road, Avondale, PA 19311.

CA Prop 65 Warning: This product contains chemicals known to the state of California to cause cancer and birth defects or other reproductive harm.

4 in stock

SKU: Mayfly-260000 EnviroDIY Shop