At the beginning of the school year Peter Shaw from the Horticulture Department asked to meet with the CS/CIS faculty about using technology in their growing operations. The Horticulture Department has magnificent greenhouses and very high tech hydroponics. So how can digital technology enable agricultural technology? The challenge seems almost too perfect a fit for exploration of the Internet of Things.
So what do you build?
We decided to take an existing function and make it more user friendly. The greenhouse has a system that uses the daily light integral to determine how much to water. It's a simple system. Light is accumulated until the measurement reaches a threshold then the water is turned on for a time. So how could a system that has two parameters (threshold and duration) be unfriendly? When both parameters are set by DIP switch. Ouch!
What networked gadget measures light?
This device is designed to use solar power alone. Since it's measuring the sun it's safe to assume it will be put in the sun and the ATtiny85 processor packs a lot of Arduino compatible punch with very little power. The bulk of power consumption comes from turning the XBee on once and a while. The robotics club prototyped this circuit over the fall semester using a breadboard. Now it's time for our first PCB!