Reply To: Analog-to- Digital Converter Port on Mayfly Data Logger

Mayfly D22 is not a physical pin on the board, it’s processor pin 22, which means you set it high or low using digitalWrite commands in your sketch, just like you would with pin 8 or 9 to turn the red or green LEDs on or off. If you’re new to Arduino or the Mayfly, you might try working through example sketches or workshop sketches in our Github repo to familiarize yourself with the operation before you connect an expensive sensor like an OBS3 to a Mayfly.