Accessible IoT Plant
Introduction: Accessible IoT Plant
There are quite a few types of self-watering plants but this one adds IoT services and accessibility into the mix. I have also kept the use to 3V rather than 5V to make it easier/cheaper for the classroom.
Supplies
* Microbit V2 or V1
* Microbit Shield (any will do)
* Ultrasonic Sensor HC-SR04
* ESP8266
* 180 degree Servo SG90
* Pipet or straw
* 2 x Wooden skewers
* 1 x Tooth pick (optional)
* 3 small elastic bands
* 2 x nails or screws
* Electrical Tape
* Scissors or clippers
* Cup
* Plant
* 11 x female to female jumper wires (dupont)
Step 1: Sensing the Moisture
* Connect your Microbit to the shield
* Take 2 jumper wires, strip off the ends of one side each onto the nails with electrical tape.
* Connect the wires to a 3V positive pin and pin 0 of the microbit
* Then program the Microbit to read the moisture of the plant using Makecode
Step 2: Connecting to the Internet
* Wire the ESP8266 to the shield using jumper wires
* Make a copy of the wiring diagram in TinkerCAD circuits here
* Search Makecode extensions for "ESP8266" and add the blocks
* Follow the Makecode instructions above to connect the Microbot to the internet
* Pin 16 for the RX and Pin 12 for the TX
* Connect your sensor readings to ThingSpeak by creating a new Channel making sure you have the API keys
* Follow the extra Makecode instructions
* Make sure your sensors are recording data
Step 3: Accessibility
* We are going to make a movement sensor for audio cues
* Wire the Ultrasonic Sensor to the Microbit shield using the diagram
* Trig to Pin 1 and Echo to Pin 8
* Add the Sonar Extention to Makecode
* Follow the Makecode instructions
Step 4: Self Watering
* Add the self-watering mechanism using a servo
* Use elastic bands (or glue if you prefer) to fix the two long wooden skewers to the servo
* Use an optional toothpick to secure the elastic bands on the short side.
* Cut a hole in the pipet (or use a straw with a bend) to act as a reservoir for water
* Attach the pipet to a servo arm with elastic (or glue)
* Add the Servo extension to Makecode
* Follow the Makecode instructions
* Attach the servo to Pin 2
* Attach the mechanism to the plant or water cup. Whichever is easiest for your cup of water
* Secure the legs of the mechanism with an elastic band around the cup or plant.
* Experiment with the servo arm angles
* YOURS WILL LIKELY BE DIFFERENT ANGLES TO MINE
Step 5: Analyse Your Measurements
* Your measurements may be very different from mine
* I have experienced ranges from 700-1000 for moisture levels using different shields and materials.
* The temperature may also need to be tweaked by adding simple additions to the Makecode to add or take away degrees. 120
As above.
* Use the Thingspeak app Thingview to make a public or private page for your plant
Step 6: Extensions
Rather than use a pipet or straw improve the design using TinkerCAD 3D design.
Ideas for improvements:
* Better watering mechanism
* Using the data to predict the watering needs in a calendar
* Adding notifications from Thingspeak into Amazon Alexa using IFTTT. Link here
* Build an all in one 3D printed plant pot with water reservoir and holders for the Microbit and Sensors
* Send tweets about your plants conditions on its own account. Link here
Step 7: Don't Have Any Kit?
You can use the "potato" battery to simulate the servo responses using the TinkerCAD circuits page if you do not have any kit on you. 389