Real-Time Air Quality Monitoring with Wio Terminal + PM Sens

🔍 Why Monitor Air Quality?

Whether you're living in a traffic-heavy city, working on an indoor automation setup, or designing a smart agriculture project, air quality monitoring is becoming a must-have. Fine particulate matter (PM1.0, PM2.5, PM10) is linked to respiratory issues and visibility problems — but often, we can't "see" the problem until it's serious.

This compact project transforms Seeed's Wio Terminal into a standalone dashboard that continuously displays PM data from a DFRobot laser particle sensor, using its built-in LCD and default fonts — no SD cards, no Wi-Fi required.

🧰 Hardware Used

> You can use a Grove-to-pin header adapter or wire the sensor directly to Grove I2C port.

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📷 What It Looks Like

Imagine this: your Wio Terminal sits on a desk or a window, with a modern, real-time dashboard showing:

[ Air Quality ]

Standard PM
 PM1.0 : 012 ug/m3
 PM2.5 : 034 ug/m3
 PM10  : 056 ug/m3

Atmospheric PM
 PM1.0 : 011 ug/m3
 PM2.5 : 030 ug/m3
 PM10  : 051 ug/m3

All data is wrapped inside colored rounded boxes for clarity and style — all using the default built-in font. 🎯

🧠 Example Use Case

Let’s say you're working on a smart greenhouse project with ESP32 and Wio Terminal. You want to:

• Keep track of indoor air quality to optimize plant growth
• Send PM2.5 alerts to Telegram when levels spike
• Mount this Wio Terminal on a wall for real-time feedback to workers

This project becomes your edge dashboard. Bonus: it's USB-powered and portable — no PC needed!

🔬 About the DFRobot PM Sensor (SEN0460)

The DFRobot Gravity PM2.5 Air Quality Sensor is a compact, laser-based particle sensor designed for real-time air quality monitoring. It’s ideal for both indoor and outdoor applications where accurate particulate measurement is critical.

🌟 Key Features:

• Laser Scattering Technology: Detects particles as small as 0.3μm using Mie scattering theory
• Measures PM1.0, PM2.5, and PM10: In both standard and atmospheric calibration modes
• I2C Interface: Easy integration with microcontrollers like Arduino, ESP32, and Wio Terminal
• Fast Response: <1s single response time, with continuous acquisition support
• Compact Design: Just 12mm thick — perfect for portable or embedded systems

This sensor is widely used in smart homes,air purifiers,greenhouses, and environmental monitoring stations.

🧠 About the Wio Terminal

The Wio Terminal by Seeed Studio is a feature-packed development board that combines a powerful microcontroller with a built-in display, sensors, and wireless connectivity — all in a compact enclosure.

🧰 Core Features:

• Microcontroller: ATSAMD51 (ARM Cortex-M4F @ 120MHz)
• Display: 2.4" TFT LCD (320×240 resolution)
• Connectivity: Dual-band Wi-Fi + BLE 5.0 (via RTL8720DN)

Built-in Peripherals:

• Microphone, buzzer, light sensor, IR emitter
• 3 user buttons + 5-way joystick
• microSD card slot

I/O Options:

• 2 Grove ports for plug-and-play sensors
• 40-pin Raspberry Pi-compatible GPIO header

Power: USB-C with OTG support

🧩 Why It’s Perfect for This Project:

• No extra display needed — the built-in screen is crisp and responsive
• Plug-and-play I2C — just connect the PM sensor to the Grove I2C port
• Portable and USB-powered — ideal for desktop or wall-mounted dashboards
• Expandable — you can add Wi-Fi alerts, SD logging, or even gesture control later

Whether you're building a smart home node or a standalone air quality kiosk, the Wio Terminal gives you a polished, professional edge right out of the box.

👨‍💻 How It Works

The DFRobot sensor uses laser scattering to count particles and report concentrations in micrograms per cubic meter (μg/m³) across two calibration standards:

• Standard Particulate Concentration – clean chamber readings
• Atmospheric Particulate Concentration – real-world calibration

We read both, then visually present them on the screen in a way that’s easy to monitor from a few feet away.

📦 Arduino Code Overview

• Initialization: Starts I2C for the sensor and configures Wio Terminal’s TFT LCD
• Layout drawing: Titles, boxes, and labels drawn once in drawLayout()
• Loop: Reads PM values and updates only the value section, reducing flicker
• Visual polish: Adds spacing and rounded rectangles for clean separation

You’ve already got this working — nice job tuning that UI, by the way. 👏

#include "DFRobot_AirQualitySensor.h"
#include <TFT_eSPI.h>
#include <SPI.h>

#define I2C_ADDRESS 0x19
DFRobot_AirQualitySensor particle(&Wire, I2C_ADDRESS);
TFT_eSPI tft = TFT_eSPI();

void drawLayout() {
  tft.fillScreen(TFT_BLACK);
  tft.setTextColor(TFT_WHITE);
  tft.setTextSize(2);

  // Title
  tft.setCursor(90, 10);
  tft.println("Air Quality");

  // Boxes
  tft.drawRoundRect(10, 40, 300, 100, 8, TFT_CYAN);     // Standard Box
  tft.drawRoundRect(10, 150, 300, 100, 8, TFT_YELLOW);  // Atmospheric Box

  // Section Labels
  tft.setCursor(20, 45);
  tft.setTextColor(TFT_CYAN);
  tft.println("Standard PM");

  tft.setCursor(20, 155);
  tft.setTextColor(TFT_YELLOW);
  tft.println("Atmospheric PM");
}

void setup() {
  Serial.begin(115200);
  tft.begin();
  tft.setRotation(3);
  drawLayout();

  while (!particle.begin()) {
    tft.fillScreen(TFT_BLACK);
    tft.setCursor(40, 120);
    tft.setTextColor(TFT_RED);
    tft.setTextSize(2);
    tft.println("Sensor not found!");
    delay(1000);
  }

  Serial.println("Sensor initialized.");
  delay(500);
}

void loop() {
  uint16_t pm1_std  = particle.gainParticleConcentration_ugm3(PARTICLE_PM1_0_STANDARD);
  uint16_t pm25_std = particle.gainParticleConcentration_ugm3(PARTICLE_PM2_5_STANDARD);
  uint16_t pm10_std = particle.gainParticleConcentration_ugm3(PARTICLE_PM10_STANDARD);
  uint16_t pm1_air  = particle.gainParticleConcentration_ugm3(PARTICLE_PM1_0_ATMOSPHERE);
  uint16_t pm25_air = particle.gainParticleConcentration_ugm3(PARTICLE_PM2_5_ATMOSPHERE);
  uint16_t pm10_air = particle.gainParticleConcentration_ugm3(PARTICLE_PM10_ATMOSPHERE);

  // Clear previous readings
  tft.fillRect(15, 70, 280, 60, TFT_BLACK);
  tft.fillRect(15, 180, 280, 60, TFT_BLACK);
  tft.setTextColor(TFT_WHITE);
  tft.setTextSize(2);

  // Standard Readings
  tft.setCursor(25, 75);
  tft.printf("PM1.0 : %3d ug/m3", pm1_std);
  tft.setCursor(25, 95);
  tft.printf("PM2.5 : %3d ug/m3", pm25_std);
  tft.setCursor(25, 115);
  tft.printf("PM10  : %3d ug/m3", pm10_std);

  // Atmospheric Readings
  tft.setCursor(25, 185);
  tft.printf("PM1.0 : %3d ug/m3", pm1_air);
  tft.setCursor(25, 205);
  tft.printf("PM2.5 : %3d ug/m3", pm25_air);
  tft.setCursor(25, 225);
  tft.printf("PM10  : %3d ug/m3", pm10_air);

  delay(1000);
}

🔧 Possible Extensions

You can evolve this project in multiple directions:

1. 🟢 Add color-based warnings

if (pm25_std > 100) tft.setTextColor(TFT_RED);
else if (pm25_std > 50) tft.setTextColor(TFT_YELLOW);
else tft.setTextColor(TFT_GREEN);

2. 📤 Push to Telegram

You can use your ESP32-S3 as a comms bridge via UART or MQTT to post air quality status every 10 minutes — something you’re already amazing at.

3. 💾 Save to SD card or send to cloud

Wio Terminal supports file logging and HTTP requests if you want historical data storage.

🎯 Final Thoughts

This project is a fantastic entry into environmental sensing, and the Wio Terminal makes it easy to deploy a full GUI dashboard with no extra components. Its portability and clean visuals make it great for makers, offices, workshops, or classrooms.