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

Digital Humidity/Temperature sensor

This example Arduino sketch will allow the Mayfly to receive data from a Grove DHT sensor (digital humidity/temperature).   You will need the DHT library available at the link above.  Connect the sensor to the D10-11 pin of the Mayfly.  In order to apply power to the D10-11 (and the D6-7) Grove sockets, you must activate the switched 3.3v power line.  This is controlled by declaring pin D22 as an output and the setting D22 high.  See the “setup” part of the example below to see exactly how to turn on the switched 3.3v line: