The Root Kit, greenSTEM’s physical product, measures soil moisture and temperature in Philadelphia schoolyard rain gardens. Students can solder circuit boards and build soil moisture sensor units to be placed in schoolyard rain gardens. These sensors wirelessly send the data to greenstemnetwork.org in real time, for all to access. The Root Kit provides a platform for students to explore technology, science, and sustainability through real world data.
All software for this project is open source and freely available on our GitHub page. These are the basic components of the software:
- Download the Arduino software for free. It is based on C/C++.
- Arduino-based code that reads soil moisture sensor data on the JeeNode in the garden, and sends it to the receiving unit in the classroom via a radio signal.
- Arduino-based code that receives the data from the garden on a JeeLink connected to the USB port of a Raspberry Pi.
- A Python script loaded onto the Raspberry Pi that sends the JSON-formatted data to a server.
- A Rails application that serves as a database and interface for the data.
- An HTML5-based visualization that is displayed at greenstemnetwork.org
The Arduino codes for the JeeNode and JeeLink require the JeeLib library. The JeeNode is sold as a kit that needs to be soldered; instructions on how to do that are here. (This is a great activity for students—under supervision, of course.)
The pinout configuration on a JeeNode is different from the Arduino. In English: where you plug in the sensor wires and how you reference them in the code will be slightly different than on the Arduino. Technical details are here.
The Root Kit setup is somewhat similar, and owes much gratitude, to the Dive Into JeeNodes wireless sensor network project.
The Root Kit monitors soil moisture and temperature and transmits the data in real time to a web display. It consists of the sending unit (on the right in the photo), and the receiving unit (on the left in the photo). The sending unit is placed outside in the schoolyard and its three soil sensors are buried in the ground. The receiving unit sits anywhere within the school and uses WiFi to upload the data to the website.
This schematic illustrates how the Root Kit sends data from a rain garden to this website.
A materials list for the Root Kit is below. We do not endorse any particular vendor for these products—all can be ordered online and prices vary.