Smart 3D Printer Air Filtration System

An Arduino-based smart air filtration and safety system for 3D printers, featuring automatic operation, VOC monitoring, and fire detection.

Features

• Automatic fan control based on Ultimaker printer state via API
• VOC (Volatile Organic Compounds) monitoring with SGP30 sensor
• Temperature and humidity sensing with Si7021 sensor
• Fire detection with automatic printer power cutoff and alarm
• PWM fan speed control (25 kHz frequency)
• Cool-off period after print completion
• HEPA and carbon filtration
• Built-in safety features including emergency power shutoff

Hardware Requirements

Main Components

• Arduino Nano 33 IoT
• 140mm PWM Fan
• 12V 3A power supply
• Relay module
• HEPA filter
• Carbon filter
• Lexan sheets for enclosure

Sensors

• Adafruit SGP30 VOC sensor
• Adafruit Si7021 temperature/humidity sensor
• Flame sensor
• TCA9548A I2C multiplexer
• Piezo alarm

Software Dependencies

• Arduino IDE
• Required Libraries:
  • RTCZero
  • WiFiNINA
  • Scheduler
  • Wire
  • Adafruit_SGP30
  • Adafruit_Si7021
  • Adafruit_HMC5883_U

Pin Configuration

• Fan PWM: Pin 2
• Fan Relay Enable: Pin 4
• Alarm: Pin 6
• Flame Sensor: Pin 9
• Emergency Power Shutoff: Pin 10
• Built-in LED: Pin 13

Setup

1. Print the required enclosure parts (designs based on this Thingiverse model)
2. Cut Lexan sheets to size and assemble the enclosure
3. Wire the electronics according to the pin configuration
4. Create a secrets.h file with your WiFi credentials:

   #define SSIDNAME "your_wifi_name"
   #define SSIDPASSWORD "your_wifi_password"

5. Configure your Ultimaker printer's IP address in the code
6. Flash the Arduino code

Configuration

The system includes configurable parameters:

• Cool-off time (default: 10 minutes)
• Printer check interval (default: 2 minutes)
• Environment check interval (default: 15 seconds)
• Default fan speed (default: 75%)
• Cool-off fan speed (default: 100%)
• Flame detection sensitivity

Safety Features

• Flame detection with automatic power cutoff
• Audible alarm system
• Real-time VOC monitoring
• Emergency power shutoff relay
• Fan cool-off period after printing

Future Improvements

• Implement dynamic fan speed based on VOC levels
• Add external temperature sensor support
• Enhanced data logging capabilities

License

See LICENSE file for details.

Contact

For questions or feedback, contact [email protected]

Acknowledgments

• Hans Peter for the original enclosure design