Optimus Thyme

Inspiration

When I saw the sustainability challenge I was inspired by something I would personally like to have. I would love to have a garden to supplement my diet with fresh food without the environmentally depleting effects of mass agriculture. However, college is a busy period of life and I often lack the time to sustain a garden. I am also lacking in green thumbs, every plant I touch tends to die. As such, inspiration struck me to automate the garden so I could get my fresh veggies without having to manually maintain a garden.

What it does

The Optimus Thyme monitors the humidity and temperature of the garden, sampling every 2 seconds. If the water level of the soil drops below optimum level, it automatically waters it using the built-in reservoir. The temperature is programmed for a range ideal for plant growth (18-24 degrees Celsius). If the temperature drops too low, it alerts the user with a blue LED and beeper to move it into the sun. If the temperature goes too high, it alerts the user with a red LED and beeper to move it out of the sun.

How I built it

The Optimus Thyme is constructed using an Arduino Uno as the "brain", which is connected to a DHT-11 temperature and humidity sensor which provides the status of the garden. The water valve is constructed using a plastic cup reservoir held by Popsicle sticks with a drinking straw through the bottom which controls the flow of water with a servomotor linked to the Arduino.

Challenges I ran into

Debugging the sensor was an ordeal, to say the least. Several minutiae of the code are required for it to take in a valid reading, so I spent several hours getting the sensor to work properly. Additionally the water reservoir required several iterations to get working properly.

Accomplishments that I'm proud of

I am proud that I was able to create a system that at least mostly works for a genuinely practical purpose. Win or lose, I can still use this prototype or its successor as a garden for my personal use.

What I learned

I learned how to use sensors with Arduino and how to do more with one than just run LEDs (my only prior experience). I also learned about gardening and how best to maintain vegetables and herbs.

What's next for Optimus Thyme

I would like to expand Optimus Thyme to feature wireless connectivity leveraging something like google cloud to send the user garden health reports and send notifications to their phone. I would also like to expand the maintenance features to include a sun lamp and shade so the unit can be completely self-sufficient.

Built With

• arduino
• dht.h
• servo.h