Monday, March 29, 2010

Fabrication of Solar Powered Sensor Stations

After having a group discussion about the strengths and weaknesses of every team's prototypes, we decided on fabricating two different designs and then testing to see which device would work best. One device uses a vertical axis to turn a cylindrical mounting for the solar panel, while the other design uses a gear/linkage to turn the panel along a horizontal axis. The teams went to work on the fabrication process and the designs are looking really good. Some students worked on the sensor station mounting board that will secure the micro-controller to the inside of the water proof casing. One student is also finalizing the software for the sensor stations which will include four humidity sensors, and the control routine for the solar tracker. We are getting very close to completion!

Powering the Irrigation System and Beyond

The components for powering the irrigation system have all arrived (panels, linear actuators, pillow blocks, charge controller, inverter). The tracking system, designed by one team, will consist of a linear actuator as opposed to a servo. The panels will be mounted on an axel that will swivel between two pillow blocks. The linear actuator will tilt the panels according to the same mechanism used in the sensor stations - two photocells with a small shade divider between them. We anticipate this system of panels will produce more energy than we currently need. That means we can use it to also possibly power a future lighting system and/or webcam for security and monitoring. Future plans also include a small greenhouse, aquaponics and more!

Tuesday, March 9, 2010

Solar Tracker Prototypes Complete

Once the students had learned to sense the soil and sunlight for the garden irrigation system, they then began the work of designing a solar tracking system that would be hooked up to the micro-controller so that the entire system could be "off-grid". The students were broken into teams to design different prototypes for the solar tracker. The students are also in the process of learning how to control servos, so once they have the design, they will build the design and program the micro-controller to move the servo so that the solar panel tracks the sun's position. The students will then judge the designs of all the teams and a decision will be made to see which design makes the most sense. So far the designs are looking really good! Nice work teams.