Green Detect Environmental Sensor Network

Environmental monitoring is easy enough with access to the electrical grid and the Internet, but what about when these modern day conveniences aren’t readily available, e.g. out in a more natural setting? To facilitate tracking of environmental factors in potentially remote locations, Sergio Ghirardelli has come up with a wireless monitoring system called Green Detect.

The setup consists of an array of sensor modules, each controlled by a Wemos D1 mini Pro ESP8266 board. The modules communicate wirelessly via the ESP-NOW protocol, and 1 to 60 units can be used together.

In use, four bits of data are sent from the first unit to the second, which adds on its four data bits. This data addition continues until it reaches the final sensor unit, where the amalgamated data can be offloaded to a supervisory computer. This configuration allows it to operate without any Internet connection, though if the supervisory computer does have a connection, data can be uploaded to the cloud for IoT functions.

Each module is solar powered, with either a 400F supercapacitor or two NiMH batteries used for storage. A number of different sensors can be attached, such as an IR unit for fire detection, temperature sensor, ultrasonic sensor, and more. Multiple sensors can be used with each module, though the four-bit data limit puts a cap on how much info can be transferred.

Maximum suggested distance between units is 100 meters, so with 60 units, six kilometers could be covered in a line. It can also be set up in a grid configuration. More details on the project can be found in Ghirardelli's write-up, while the video below gives a nice overview.