This was my final project for my Arduino Prototyping capstone class. Our groups partnered with a local elementary school to address a problem/interest the students wanted to explore. My group worked with students who were interested in doing experiments with hydroponic plant growth, so we made them a hydroponics lab. 

 

Our main goal in the design process was to give the students something that aided in learning, not just giving them the answers. We wanted to provide tools for them to go further with their experiments instead of just telling them that their environment was right or wrong. This project should make it easier to visualize and adjust variables important to plant growth so the students can discover for themselves what combination of factors is the most conducive for plant growth. 

 

We ideated a control center on top of a hydroponics kit (plastic box with holes for the plants and basin for the water) that contained sensors and controls for temperature, light, and pH. Our model had a "set, check, adjust" framework (marching band reference for any band kids out there!) -- we used potentiometers for students to set the ideal light/temperature/pH level for the plants and neopixel rings to visualize how far the dial had turned. We then used appropriate sensors to check the current environmental levels compared to the set level. Finally, external sources (supplementary light, heating pads, pH solution) would be activated accordingly to try to make the environmental level match the set level. 

 

We achieved this framework for light, utilizing a neopixel ring that turned on progressively if more light was needed in the environment and slowly turned off if it was too bright, with an additional indicator LED to notify if, even with the neopixel fully on or fully off, the environment was still too dim or bright, respectively. This notifies the students that they may need to move the plant to a whole different environment. 

 

For temperature and pH, we were only able to implement the set and check portions. The heating pads and motor to pump pH solution proved to be too high voltage for our Arduinos to handle, so we pivoted our design to just include helpful indicators of whether the ideal temperature or pH matched the environment. 

 

The design and experimentation process, though not 100% successful in the end, was extremely fun and fulfilling, especially knowing we were making something to address the needs/interests of elementary students. 

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Because I was responsible for the light portion of the project, the process photos, demo video, and detailed report mostly focus on that aspect of the project with a few additional assembly photos when we tried to put everything together.