ESP32 Air Quality Monitor FYP with MQ135 and BME280: What Is Accurate and What Is Not
Use MQ135 and BME280 safely in an FYP without overstating ppm accuracy or CO2 measurement quality.
Rectronx
2026-07-12
Quick Summary
This guide helps students build a realistic air quality monitoring final year project with a clear scope, common components, safe assumptions, and demo evidence that examiners can understand. The goal is not to promise an industrial product. The goal is a stable academic prototype with measurable behavior.
Project Scope
A strong FYP scope should include input, processing, output, data record, and a clear user workflow. For this project, the expected outcome is relative air-quality trends, temperature, humidity, pressure, and alert threshold demos.
Keep the first version small. A project with fewer features but repeatable test results usually scores better than a large system that only works once during demonstration.
Suggested Components
A practical component stack is: ESP32, MQ135 gas sensor, BME280 temperature-pressure-humidity sensor, OLED, enclosure with airflow, and IoT dashboard. You can replace parts depending on budget and availability, but keep the same system roles: sensor or input, controller, output, storage, and user interface.
Build Steps
- Test every sensor or input module alone before combining the system.
- Confirm the controller power supply is stable under real load.
- Add the decision logic, thresholds, or prediction workflow.
- Add the dashboard, display, or report page.
- Record repeated tests for normal cases and failure cases.
Accuracy and Safety Notes
MQ135 is not a precise CO2 meter; describe it as relative gas/air-quality indication unless calibrated with proper reference equipment. Include this limitation in your report because honest technical boundaries make the project look more professional, not weaker.
Common Mistakes
- Combining all modules before testing each one separately.
- Powering motors, relays, GSM modules, or cameras from weak controller pins.
- Building only a nice interface without real workflow validation.
- No fallback method when a sensor, network, or login fails.
- Claiming high accuracy without a reference instrument or proper dataset split.
What to Show During Demo
Show the input changing, the system decision, the stored record, and the final output. For your report, include wiring photos, screenshots, test tables, and a short limitation section.