Introduction: Michael the Field Hand
Need a convenient and stylish way to make sure your plants are watered and happy? Look no further than Michael! Running off an Arduino Mini and rechargeable 3.7 volt battery, Michael can accurately and consistently tell how wet the soil around your plant is, and let you know if it needs more water. Using a Phantom moisture sensor, Michael digs prongs into the soil to measure its overall moisture and turn on an LED when the moisture is below a certain level. That way when the plant is watered, the device does not disturb you, but when it needs to be watered, the light is a subtle way of notifying the user.
Step 1: Materials
Arduino Pro Mini
3.7V Rechargeable Battery
Phantom YoYo Arduino compatible High Sensitivity Moisture Sensor
Soldering Iron and Wire
Step 2: Mind Over Matter
As any good sensor needs to be programmed, I narrowed my computer choice to an Arduino Mini Pro. I clipped off some unnecessary prongs and soldered the device together. Only to realize, I had installed the Arduino upside down, doing so caused it to fry when I fired up the sensor; meaning I had to program and install an entirely new Arduino. This time around, I was inspired to make my Arduino removable so that any problems with it would not require the device to be fully taken apart and rewired again.
Step 3: Getting a Sense
Once I had my Arduino coded properly, the next step was wiring the computer to the sensor and battery. I initially wanted to power the device with a 9-volt duracell, but a 3.7v rechargeable battery was suggested, and I am rather happy with the upgrade. Initially, I used a breadboard to link the pieces together, but soldering the wires proved to both make a stronger connection and to shrink the device substantially.
Step 4: We Have the Technology...
Now that you have a brain, you need a body to keep it in. Initially, I 3D printed a case with the shape of a flamingo, or swan; the first print experienced structural problems, and I wasn't satisfied with the second attempt, so I decided to design a more modular case that could hold all the components more easily.
The first step was to determine a proper size, I went through a few drafts here using foamcore until I determined that an equal 2x2x2 inch case would be ideal. From there I added slits for the sensor's prongs to fit in and a gap where the switch could be fitted. It was here that I decided to add some stylistic features to make the advice more aesthetically pleasing.
Once I had the shape and design down, I knew I needed to use a better material, I initially sought out plywood, but was unable to get the cut I would like, I was inspired to try Acrylic, as I could get a better cut and the clarity of the material would help us more easily see the light..