STELLA-AQ Technical Details
The STELLA-AQ (Air Quality) instrument delivers comprehensive atmospheric monitoring capabilities through an integrated sensor array and robust data collection system. Built around a Feather STM32F405 or Thing Plus RP2040 microcontroller, this scientific instrument combines precision sensing with user-friendly operation.
Core Components
- Microcontroller: Feather STM32F405 or Thing Plus RP2040
- Real-Time Clock: PCF8523 with battery backup for accurate timestamping
- Display: 128×128 OLED for data visualization
- Data Storage: Micro-SD card for CSV data logging
- Power: 3.7V rechargeable lithium-ion battery with integrated charging circuit
Sensor Suite
- Particulate Matter: PMSA003I sensor monitoring 2.5ppm to 10ppm concentrations
- Carbon Dioxide: SCD-40 photoacoustic CO₂ sensor
- Methane: Dedicated methane detection capability
- Environmental Parameters: BME280 sensor measuring:
- Barometric pressure
- Relative humidity
- Air temperature
- Altitude
System Features
- Calculated Metrics: Automatic calculation of dew point and particulate ratios
- Connection System: Qwiic/STEMMA-QT connectors for solderless assembly
- Software Platform: CircuitPython programming environment
- Interface: Power switch and intuitive control system
- Housing Options: Can be secured to a ruler or mounted in a jewelry box enclosure
- Construction Cost: Approximately $200 using commercial off-the-shelf components
- Assembly Complexity: No soldering required, connector-based construction
The STELLA-AQ represents an accessible yet powerful platform for air quality assessment, combining professional-grade sensing capabilities with educational accessibility for scientific monitoring and analysis.