The system is based in two sensors. Each sensor is built using galvanized nails connected to an analog port and making a resistor division with another resistor. The sensors also keeps the nail separated in a distance equivalent of 1.5 inches using pieces of foam that I found in the trash. Yes! the system is simple, cheap and you can monitor your soil only using nails. I choose galvanized for obvious reasons.. I do not want to see the nails rusted in a short period of time.
This is more than enough to check if soil has water in good amount to the plants or not. Considering was a fair, I build a LED matrix in order to show a happy or sad face. This face has a push button as well.
Galileo is a microcontroller board based on the Intel® Quark SoC X1000 Application Processor, a 32-bit Intel Pentium-class system on a chip (datasheet). It’s the first board based on Intel® architecture designed to be hardware and software pin-compatible with Arduino shields designed for the Uno R3. Digital pins 0 to 13 (and the adjacent AREF and GND pins), Analog inputs 0 to 5, the power header, ICSP header, and the UART port pins (0 and 1), are all in the same locations as on the Arduino Uno R3. This is also known as the Arduino 1.0 pinout.