This was a must; panStamps had to be able to measure soil moisture as well! A new low-power application has been released This application reads moisture levels from up to two soil sensors, probably installed at different depths. panStamps running this application can be mounted on one of our battery-boards or simply be powered from a couple of AA/AAA batteries.
Our transmitter can be connected to any soil moisture sensor providing a voltage signal between 0 and Vcc (3~3.3VDC). We have been using some cheap resistive sensors for our tests but you can use any other professional transducer.
In order to build your own transmitter you have to grab a panStamp with the "soilmoisture" application, downloadable with the rest of sample sketches from our download section. Then the Tx interval has to be set from SWAPdmt accordingly since we may want to do just a few measurements per day. In fact, powering the sensors from digital pins lets us remove the power when the panStamp is sleeping.