The sword in the stone now sits among other stones at Greenfield Elementary School. This stone, however, hides a Root Kit, sending soil moisture data to our growing tree. A slight modification was made to the stone when we drilled a pinhole in the top for the Root Kit’s antenna to poke out. Increasingly, we’re finding out that a line of sight between the two antennas is an important factor in keeping the radio signal alive. (For a refresher on how this set-up works, go here.)
Thanks to Mr. Bentz and his 8th grade class, who buried the sensors; and to Drexel co-op Darya Drahun for technical assistance. We noticed during our visit that Greenfield is installing a green roof directly below the science classroom; this would be a fascinating new home for the sensors next year.