First, let us tell you more about ourselves:
We are two : Baptiste and Andreas, both french students in mechanical engineering. This was our first electronic project and it was done as part of our engineering degree.
What we can offer you is an autonomous garden that can grow up to 6 aromatic plants and was designed to operate without any human interaction for at least 3 weeks.
The garden can be assembled and dissembled without any tools and it measures 420x310mm.
Now, let's start working!
Step 1: Introduction
List of material:
- wood (MDF 6mm)
- Arduino nano
- Electric wires
- LED (for plant growth and warning light signal)
- Light sensor
- Moisture sensor
- Pipes (4mm internal diameter)
- Angles for pipes
- 6 square pots of 90 * 90mm
- Tank (6,5 liters)
- Laser cutting machine
- Soldering iron
- Glue gun
Step 2: Wood Cutting
We have design each and every part of our garden that will assembled later. The garden can be assembled and dissembled simply using our pin system. In order to make the cuts as accurate as possible, we used the laser cuter available at our school.
Here are all the plans, available both in .stl and .dxf format.
Our hole design can only fit 90x90mm pots.
Of course, all the files are editable as needed.
In total, 16 pieces are cut including the 8 pins.
Step 3: Assembly
Once the cuts have been made, you must assemble the garden using the pin system as shown.
Step 4: Electronic Part
The brain of the electronic system is an Arduino Nano. It collects the various data from the sensors (humidity, brightness and water level) to adapt/adjust the controls (lighting , watering, lighting the LED).
A horizontal humidity sensor is used to check the water level. If the tank is empty, a red LED will turn on to let the user know that the tank must be filled.
Step 5: Process Part
Drill the water tank and the bottom of the top support of the garden. Insert the dispenser into the holes thus formed and glue it so that it is watertight. Connect the various hoses and connections to the solenoid valves. Then fix the solenoid valves to the frame. Connect the outlet pipes of the solenoid valves and route them to different tanks.
Drill 2 holes on the front to insert the red LED and the photoresistor.
The top plate must also be drilled with a 50mm diameter hole and then sticks a piece of pipe that will fill the tank.
A handle is also attached to facilitate opening.
Step 6: Arduino Code
Here you can download our Arduino code.
The solenoid valves open when the hygrometry sensor detects a lack of water. The lighting is controlled by the brightness sensor (a photoresistor). Our settings have not been tested over a long period, some thresholds we have defined are certainly not optimal. You can modify them in the code as needed.
The red LED under the brightness sensor is lit when the low level of the tank is reached.
Step 7: Planting
All kinds of aromatic herbs can be grown in the garden. For this, fill the earthen pots and plant the seed, the kitchen garden takes care of the rest!