Pollen Detection System for Allergy Prevention



About: The BCAMRL is a Mechatronics Research Lab, founded in 2014 on the campus of Bergen County Academies, a magnet high school within the Bergen County Technical School District. Students create innovations base...


In the United States, 25 million people in the world have asthma, a respiratory illness, that causes difficulty breathing. This illness can be triggered by many factors such as air quality, pollen, dust, temperature, etc. Once triggered, asthma causes one’s throat to close, making breathing difficult and causing that person to become light-headed. The main solution to asthma is an inhaler, prescribed by a doctor; however, inhalers only provide a brief respite and most of the time it is inefficient to wait to use an inhaler until one experiences an asthma attack. How can these life threatening asthma attacks and dilemmas be prevented? The goal of this pollution and environment sensor is assess the asthma patient’s location and predict if that location can trigger one’s asthma before that person experiences the asthma attack. The expected outcome is a portable device that can detect the air quality, temperature, and humidity around asthma patients. If any of these factors exceed the individual threshold set by the patient, then the patients will be notified to stay clear of that area or to keep their inhaler close. If this idea is functional, then people will have a better defense against their asthma attacks because the best way to prevent asthma attacks is to avoid areas that will trigger them. A long term goal is to have this concept be modified to be used as air quality detectors set with adjustable settings for cars, buildings, and public places to monitor allergies and illnesses.

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Step 1: Parts List

Components needed for the project:

  • Optical Dust Sensor
  • RGB Cathode LED
  • Piezo Buzzer
  • LM35 Temperature Sensor
  • 3 x 4.7 kΩ Resistors
  • 1 x 100 Ω Resistor
  • Liquid Crystal Display
  • Proto Shield
  • Arduino Uno

Step 2: Arduino Assembly and Pins

Frist, solder the pins onto the proto shield and insert it into the Arduino uno. Then, attach the LCD display onto the proto shield. By doing this, the initial prototype c

Step 3: Pin Information

  • Pin A1 → Temperature Sensor
  • Pin 11 → Red Led of RGB
  • Pin 12 → Green Led of RGB
  • Pin 13 → Red Led of RGB
  • Pin 2 → Buzzer
  • Pin 7 → Dust Sensor (Yellow)
  • Pin A0 → Dust Sensor (Blue)

Step 4: Connect the Dust Sensor

The Grove Sensor has three cables:

  • Red → 5V or power
  • Black → Ground
  • Yellow → Digital Pin 7
  • Blue → Pin A0

Using a jumper cable connect the 5V on from the Arduino to one of the power rails on the breadboard. Using another jumper cable, connect the Ground from the Arduino to the other power rail. These two power rails will provide the source of power and ground for the following component placements.
Connect the red cable from the dust sensor to the 5V power rail, the black cable to the negative power rail, the yellow cable to Pin 7, and the blue cable to Pin A0 on the LCD display as shown above.

Step 5: Connect the RGB Cathode LED

The RGB Led includes four pins:

  • Ground Pin (since it is a cathode LED) → Negative Rail on Breadboard
  • Red Pin → Pin 2
  • Green Pin → Pin 3
  • Blue Pin → Pin 4

Using the 4.7 kΩ resistors, connect the RGB LED onto the breadboard following the schematic above. Each pin should be connected to a 4K7 resistor which should be connected to their corresponding pin numbers using jumper cables. *Note*: An anode RGB LED can be used as well. In this case, the second pin would be attached to the positive rail.

Step 6: Connect the Piezo Buzzer

The Piezo Buzzer used in this project has two leads:

  • Ground Lead → Negative Power Rail on Breadboard
  • Data Lead → Pin 2

Using the 100 Ω resistor, connect the Buzzer onto the breadboard as shown from the schematic above. The data lead should be connected to the 100 Ω resistor, which should be connected to pin 11 via a jumper cable.

*Note*: When developing code, the buzzer will be used in if else statement.

Ex: if (density >= 200); {

tone(buzzer, 25);


This will not be sufficient for the buzzer to work properly. If this is done, the buzzer will buzz disregarding the parameters that are set for it. The solution is to create an array for the ratio values that the buzzer can read and determine if it should buzz or not. See the completed array code lines in Step 11.

Step 7: Connect the Temperature Sensor

The temperature sensor has three leads:

  • 1 → Power, connected to the positive rail on the breadboard
  • 2 → Data, connected to pin 0 on the LCD display
  • 3 → Ground, connected to the negative rail on the breadboard

If temperature sensor starts overheating, mount the temperature sensor on a mini breadboard piece and insert it into the breadboard circuit.

Connect the pins described above to their respective slots in the breadboard and the LCD + Arduino as shown above.

*Note*: The temperature sensor gives values based on the amount of voltage it receives, and therefore depending on the setup of the individual circuit and the amount of voltage through the sensor, the equation to calculate the temperature may have to be adjusted.

Step 8: Download Libraries

Download the Liquid Crystal Display library from https://playground.arduino.cc/Main/LiquidCrystal.
The library is needed in order to write code involving the LCD display.

Step 9: Solder Components Onto Proto Shield

After everything is set up on the breadboard, solder all the components, cables, and connections onto the proto shield.

Step 10: Build a Case

Option 1:

Design a case on Autodesk Inventor which encloses the lcd, arduino, and other sensors. The case should also take into account that for the fact that since the sensors require contact to the atmosphere to function, the case should have an open top, exposing the sensors to the atmosphere.

3D Print the case, and secure all the electronics in the case.

Option 2:

Find a preexisting case, and drill/cut holes to secure the components. This is option taken for this project. Pictures of final case with components inside are posted.

Step 11: Code

This project uses an optical dust sensor. However, this same project can be done with a groove dust sensor instead. Other sensors must be adjusted when writing the code. Codes for the devices using both sensors are attached.

Step 12: Video



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