by FABLAB Dhahran @ instructables.com:
In this project we will design and program a smart garden watering system. This system will use Arduino UNO and a moisture sensor to measure the volumetric water content in soil. It will also have a light (photocell) sensor to detect when the plant should get sunlight. So, when the soil is dry a red LED will light up, when it’s wet a blue LED will light up, and when the plant needs a light a white LED will blink. You will need basic 2D-designing skills and CNC machine to design and build our own planter box. Alternatively, you can just use a normal jar. Also, you can make your planter box using acrylic and cut it by a laser cutting machine.
Smart Garden – [Link]