Introduction: Plant Whisper
This project was designed to alleviate growing water problems experienced by farmers in California. As water supplies dwindle, farmers are forced to ration it out severely, often giving water to some plants at the expense of others. The purpose of this project is to provide them with information to make better decisions on water rationing, or to provide for the plant itself with precision. This is done through a network of sensors which monitor 4 aspects of the environment: light levels, humidity, temperature, and soil moisture. They feed data to a microcontroller, which formats it and displays it on a computer. The microcontroller is also hooked up to a pump (with attached water tank), and a sunroof. This allows it to add water, or give the plant shade or light when necessary. The idea is to demonstrate that such a system is possible and successful. In the future, it could be expanded to greenhouses, such as the ones being tested in Japan, or fields. It could also be improved to monitor more conditions of the environment, and be able to act accordingly. The end goal of this project is to create large water savings, by monitoring and growing each plant more efficiently.
Step 1: Materials:
7 metal rods
2 water tanks
Soil Moisture Sensor
Sabertooth 2x12 H-Bridge
9v battery pack
Step 2: Making the Base
Trace a circle around the tank on the wood. Mark holes in a “T”, two on each side of the tank, and one at the back. Additionally, place two holes some distance away, depending on how far the roof needs to extend. Drill holes, and insert the rods. (Rods may be secured using glue, duct tape, or another method of your choice).
Step 3: Making the Water Reservoir
Cut the top off one of the tanks, and the bottom off the other one. Place one around the other, and secure it. Cut a hole in one of the caps, and attach tubing. Put silicone around the hole. Attach the tank to the rods, making sure the tube points downwards, about 3-4 inches down. Secure however you want.
Step 4: Attaching the Pump
Attach tube to pump. Secure pump to a rod. Attach more tubing to the other side of the pump.
Step 5: Attaching the Motor
Drill holes at the top of the two back axles, and the two side axles attached to the tank. Attach the tank-side axle to the motor.
Step 6: Setting Up the Roof
Glue an edge of the canvas to the tank-side axle. Glue a weight to a string, then attach the string to the other end of the canvas. Loop the string over the other axle.
Step 7: Wiring the Arduino
Wire the motor and pump to the outputs of the Sabertooth
Wire up Arduino:
A0 to light sensor
A1 to soil moisture
Pin 10 to the data pin of the SHT11
Pin 11 to the clock pin of the SHT11
Pins 5 and 6 to S1 and S2 of the Sabertooth
Download sketch and SHT11 library. Upload, connect, and test.
Step 8: Mounting the Arduino
Cut a rectangle out of the garden lamp, and cover it with clear plastic. Attach Arduino, Sabertooth, and breadboard to a metal insert (via glue, tape, screws, etc). Insert into lamp, making sure to lead the wires out of the bottom. Mount wherever and however needed.
Step 9: Troubleshooting
Test that it works by moving the location, and covering up/warming it up/breathing on it. If it does, make sure it is mounted in a good location. If it doesn’t, check connections to power, ground, and data.
Check data connection to Arduino, then power connection. Swap out the sensor for an identical one to check. If it works, the original is defective.
Disconnect from H-Bridge, test using battery. If it works, check H-Bridge connections. If it doesn’t, replace motor.
Roof not moving, but motor making noise:
Reduce weight on roof
Motor coming loose:
Secure motor using better methods (duct tape and/or zip ties usually work wonders)
Check pump connections to make sure they are waterproof. If not, apply silicone
See section “Motor/pump unresponsive”. If pump doesn’t work, find higher-power pump