DreamLab
Published © Apache-2.0

Air Quality Monitoring System

Air Quality Monitoring System Using Wio Terminal and PM2.5 Sensor

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Air Quality Monitoring System

Things used in this project

Hardware components

Wio Terminal
Seeed Studio Wio Terminal
×1
Seeed Studio Grove - Laser PM2.5 Dust Sensor - Arduino Compatible - HM3301
×1

Software apps and online services

Arduino IDE
Arduino IDE

Story

Read more

Schematics

Project Diagram

Diagram

Code

Code

C/C++
#include <Arduino.h>
#include <Wire.h>
#include "Seeed_HM330X.h"

// Create sensor object (I2C mode)
HM330X sensor;

uint8_t buffer[30];

void printError(HM330XErrorCode error)
{
  switch (error)
  {
    case NO_ERROR:
      Serial.println("No error");
      break;
    case ERROR_NOT_READY:
      Serial.println("Sensor not ready");
      break;
    case ERROR_DATA_OVERFLOW:
      Serial.println("Data overflow");
      break;
    case ERROR_SERIAL_NO_ACK:
      Serial.println("No ACK from sensor");
      break;
    default:
      Serial.println("Unknown error");
      break;
  }
}

void setup()
{
  Serial.begin(115200);
  delay(1000);

  Serial.println("=== Wio Terminal Air Quality Monitor (I2C) ===");

  // Initialize I2C
  Wire.begin();

  // Initialize sensor in I2C mode
  if (sensor.init())
  {
    Serial.println("HM3301 sensor initialized successfully");
  }
  else
  {
    Serial.println("Sensor initialization failed!");
  }
}

void loop()
{
  HM330XErrorCode error;

  error = sensor.read_sensor_value(buffer, 29);

  if (error == NO_ERROR)
  {
    // Data format: PM1.0, PM2.5, PM10 (standard positions)
    int pm1_0  = buffer[4]  << 8 | buffer[5];
    int pm2_5  = buffer[6]  << 8 | buffer[7];
    int pm10   = buffer[8]  << 8 | buffer[9];

    Serial.println("\n---------------------------");
    Serial.println("AIR QUALITY DATA (I2C)");
    Serial.println("---------------------------");

    Serial.print("PM1.0  : ");
    Serial.print(pm1_0);
    Serial.println(" µg/m³");

    Serial.print("PM2.5  : ");
    Serial.print(pm2_5);
    Serial.println(" µg/m³");

    Serial.print("PM10   : ");
    Serial.print(pm10);
    Serial.println(" µg/m³");

    // Air quality classification
    String status;

    if (pm2_5 <= 12)
      status = "Good";
    else if (pm2_5 <= 35)
      status = "Moderate";
    else if (pm2_5 <= 55)
      status = "Unhealthy";
    else
      status = "Hazardous";

    Serial.print("Status : ");
    Serial.println(status);
  }
  else
  {
    Serial.print("Sensor error: ");
    printError(error);
  }

  delay(2000);
}

MQTT code

C/C++
#include <PubSubClient.h>

WiFiClient wifiClient;
PubSubClient client(wifiClient);

void reconnect() {
  while (!client.connected()) {
    client.connect("WioTerminalClient");
  }
}

void sendData(int pm25) {
  String payload = "{\"pm25\": " + String(pm25) + "}";
  client.publish("air/quality", payload.c_str());
}

Credits

DreamLab
8 projects • 9 followers

Comments

Related channels and tags
  • Internet of Things
  • Internet of Things
  • Seeed Studio