Erbbie, pronounced Kirby with an "H", is a DIY desktop smart garden designed to give everyone a green thumb. Made from an up-cycled mason jar, plastic water bottle, acrylic and an Arudino, Erbbie is a great project for makers of any age and skill set. Designed to be built in less than 5 hours Erbbie introduces makers to CAD, digital fabrication, Arduino coding and basic circuit design. Once assembled Erbbie starts measuring the environment around your plants and will light up yellow if they need more sunlight, and green if everything is going smoothly.
Step 1: Ideation, Prototyping & CAD Design
Lets start this project by thinking with our hands! I headed down to the kitchen to grab a mason jar and water bottle, but you could build this project with any other water containers you have around. The goal here was to design a simple container that allows water and nutrients to flow through the plant roots and then collects leftover water and nutrients to be reused.
CAD using Fusion 360
First of all, if you have never used CAD before I HIGHLY recommend you start with Autodesk Fusion 360. Its an amazing tool for beginners that also has some seriously advanced capabilities for when you become a CAD Jedi. For our purposes doing a basic CAD model helps us visualize our final product and start thinking about manufacturing and assembly. Our goal here is to make DXF files that can be sent to a laser cutter. If you like the shape of Erbbie I've attached my DXF files, if not design your own!
**Pro Tip** If you choose to design your own, and I recommend you try, the trick to making DXF files from Fusion 360 is to right click on the sketch (as pictured above) and click "Save as DXF".
Laser Cut Prototype
Using the Epilog laser cutter at Autodesk's Pier 9 makes super quick work of the 1/8" cardboard used here for prototyping. Just be cognizant of your laser cutters power, speed and frequency settings, please check your user manual or the companies website for recommended settings. Using improper settings is a fire hazard, please please please be careful!
Step 2: Hook Up Electronics
Now its time to make Erbbie's brain! Go grab an Arduino, and some coffee because this part is going to require some focus!
Erbbie communicates through color changes I recommend and used an Adafruit Neopixel Mini PCB, it's super easy to solder and already has all the resistors and capacitors attached. For the light sensor I used the Adafruit TDL2561. Not only is the TDL2561 easy to solder, but Adafruit has provided an awesome arduino library and examples making coding a snap.
If you don't know how to solder have no fear, there are some other great Instructables, and even a group dedicated to the art (...and science) of learning how to solder.
Now that you're up to speed grab your soldering iron, some wire and solder. In the pictures above I'm using very generic plug in soldering iron, you don't need to get fancy. Solder 3 wires, bonus points for color coding them, onto your NeoPixel and 4 wires onto your Light Sensor as shown above.
Both the NeoPixel and Light sensor are powered by +5V, notice the red alligator clip connecting both red wires. Once we validate our code works you will want to go back and solder both power wires together and plug them into the +5V coming out of the Arduino. Connect both black ground wires to ground (labeled GND on Arduino). Now plug in the middle wire from the LED, this is labeled Data In (DIN), to Pin 6. This can be put in another pin if you choose but you'll have to update the provided code to let the Arduino which pin it should use to talk to your LED. Lastly, plug your final two wires from the Light Sensor into Analog Pin 4&5 which are the fixed I2C ports on the Arduino. Adafruit has an great TSL2561 Wiring diagram and walkthrough if you still have any questions, or want to learn more.
Almost there! I've attached my Arduino Uno code, which you are more than welcome to use. It is essentially a compilation of example files from all the sensors attached. Note: You will need the TSL2561 Library and Adafruit Neopixel libraries! Here is a link for the Neopixel library and setup guide, and similarly here is the link for the light sensor. If you do not know how to upload libraries to your Arduino please check out this great tutorial by Instructable's own audreyobscura "Import a Code Library to Arduino"
Step 3: Final Laser Cutting and Assembly
Ok now that we have everything prototyped and our electronics finished lets go back to the laser cutter make our final pieces out of 1/8" white and clear acrylic. Pay attention to your printer settings! You will most likely be cutting at at higher frequency but check your manual for recommended vector cutting setting for acrylic. Try a couple of practice pieces first to home in on the right settings to make is all the way through your acrylic.
The 1/4" registration holes we added in our drawing make assembly trivial. Four 1/4"-20 bolts and nuts will hold everything together and give Erbbie some ground clearance.
YAY Lets Grow Stuff!!!
Congrats! Plug in your Erbbie and begin growing whatever you want, currently I'm growing oregano. Please post photos of your Erbbie, and share your desktop hydroponic garden with the world! Thanks for viewing :)