The Pollenpoint Flower

We have created an interactive flower device that helps alert users to the pollen levels in the room or area it is placed. This helps warn users who may suffer from hay fever and other illnesses, reminding them to take any necessary medication. The device works by having a built-in dust sensor that connects to a motor at the flower head, which turns to a certain angle when activated. The angle depends on the dust levels: 0 degrees for low and 180 degrees for high dust levels. There are three coloured circles—green, amber, and red—that help indicate the dust levels.

1. Dust Sensor (Waveshare)
2. 2x D1 minis
3. MicroServo 9g (SG90)
4. 10-12 wires
5. 2x breadboards

The Code

First of all, you have to create a code that sends data to an MQTT server. In this case, we use test.mosquitto.org. This allows the dust sensor reading to be sent by one D1 mini and accessed by the subscribing D1 mini. The main parts of the code to include are:

1. Include the necessary libraries
2. The MQTT and Wi-Fi details to ensure it connects to the correct place
3. Code that connects to the Wi-Fi and MQTT
4. Code that sets up the dust sensor
5. Code that reads the dust sensor and calculates its concentration
6. Code that sends and publishes data to the MQTT

The Circuit

When it comes to the circuit, there are a few things to consider. Firstly, ensure the D1 mini is connected to a power supply via a micro USB-C cable. From this, you want to connect the 5V and ground points to the + positive and - negative rails on the breadboard. For wiring up the dust sensor, connect the VCC point to the + positive rail and the GND point to the - negative rail of the breadboard. Make sure to connect the AOUT point to the A0 point of the D1 mini, and if you want to include the sensor's built-in LED, connect the ILED point to the D0 point.

The Code

This code acts as a subscriber that gathers data from the MQTT and does something with it. In this case, it will turn the motor. The angle of the motor will depend on the dust concentration that the D1 mini receives. The main points to include in the code are:

1. Include the necessary libraries
2. Wi-Fi and MQTT details to ensure it connects to the correct place
3. Code that connects to the Wi-Fi and MQTT
4. Code that processes the dust data and moves the servo
5. Code that changes the angle based on the dust levels
6. Code that ensures the servo is attached to both the circuit and MQTT correctly

The Circuit

For the circuit, there are some points to consider. Again, the D1 mini has to be connected to a power supply via a USB to micro USB-C cable. The servo motor has three wires: the red wire goes to the 5V supply, the brown wire goes to the GND, and the yellow wire connects to the D4 pin.

Origami Flower/Stem

For the flower, I started with four 15cm x 15cm square pieces of card, which I then folded in half three times. I drew the petal shape across the folded card and cut around the shape while also cutting off the point at the end. Once unfolded, I had four identical pieces, each making up eight petals. From there, I cut off one petal from the first piece, two from the second, three from the third, and cut the fourth one in half. After this, I overlapped the petals and glued them together. The individual petals and the two leaf petals are slightly more difficult to overlap. Next, glue the small petal into the slightly larger one and repeat this process until all petals are used up.

For the stem, I simply wrapped the green card around a thin wooden pole and glued the leaf/pointer on.

Base

For the wooden pot, the shapes were cut from MDF to the preferred dimensions, as shown. They were then glued together to create the shape. A few layers of white paint were applied to the box. Afterwards, several layers of brown paint were added to give it the appearance of a pot. A final layer of blue/green paint was applied to the top edges of the pot.