The MAX30105 High Accuracy I2C Optical Particle Sensor Module is an integrated multi-wavelength optical sensor module designed for precision particle detection, smoke and aerosol sensing, proximity detection, and biometric photometry. Manufactured around the Maxim Integrated (Analog Devices) MAX30105 IC, it packages internal optical elements including three internal LEDs (Red at ~660 nm, Infrared at ~880 nm, and Green at ~537 nm), a high-sensitivity photodetector, low-noise analog front-end (AFE) electronics, and a 32-sample FIFO data buffer. Communicating over a standard I2C interface, it enables non-destructive optical monitoring of ambient airborne particulates, rapid fire/smoke detection, fire alarm prototyping, and high-SNR pulse oximetry and heart-rate monitoring applications.

Specifications

• Integrated Sensor IC: Maxim Integrated / Analog Devices MAX30105
• Optical Emitter Architecture: 3 Integrated LEDs
  • Red LED: Peak wavelength ~660 nm
  • Infrared (IR) LED: Peak wavelength ~880 nm
  • Green LED: Peak wavelength ~537 nm
• Photodetector Architecture: Integrated High-Sensitivity Silicon Photodiode with integrated ambient light cancellation
• Operating Supply Voltages:
  • Core / Logic Supply (VDD): 1.7 V to 2.0 V (Breakout modules typically integrate a 3.3V/5V LDO regulator)
  • LED Anode Supply (VLED+): 3.1 V to 5.25 V (Directly drives internal high-current LED pulses)
• Supply Current Profile:
  • Active Sensing Mode: ~600 μA to 1.2 mA (Dependent on programmed sample rate and LED pulse width)
  • Shutdown / Standby Current: 0.7 μA typical
• Programmable LED Drive Current: 0 mA to 51 mA per channel (8-bit resolution, 256 discrete current steps: ~0.2 mA/step)
• Programmable LED Pulse Width: 69 μs, 118 μs, 215 μs, and 411 μs
• Analog-to-Digital Converter (ADC): High-Resolution Sigma-Delta ADC with 15-Bit to 18-Bit selectable resolution (Tied to pulse width)
• Sampling Rate Options: Selectable from 50 Hz up to 3200 Hz (Samples per second)
• On-Chip Data Storage: 32-Sample First-In, First-Out (FIFO) hardware buffer to offload microcontroller polling
• Digital Interface: Standard I2C Serial Interface (Supports Standard 100 kHz, Fast Mode 400 kHz, and Fast Mode Plus up to 3.4 MHz)
• I2C 7-Bit Slave Address: 0x57 (Fixed hardware address)
• Integrated Temperature Sensor: On-chip die temperature sensor (±1°C accuracy, 0.0625°C resolution) for thermal drift compensation
• Operating Temperature Envelope: -40°C to +85°C
• Form Factor: Compact Breakout PCB (Approx. 12.7 mm × 12.7 mm to 15.0 mm × 25.0 mm depending on module vendor)
• Module Net Weight: Approx. 1.2 g to 2.0 g

Features

• Multi-Spectral Particle Discrimination: Emitting three distinct wavelengths (Red, IR, Green) allows differential light-scattering calculations, distinguishing between coarse dust particles, fine smoke/combustion aerosols, and transient proximity obstructions.
• Robust Ambient Light Rejection: Proprietary analog front-end circuitry automatically cancels out continuous ambient background illumination and 50Hz/60Hz artificial room lighting hum, preventing photodetector saturation.
• Integrated 32-Sample Hardware FIFO: Buffers reading frames internally, allowing the host microcontroller to enter low-power sleep and process readings in bulk via hardware interrupt (INT) lines rather than continuous polling.
• Programmable Dynamic Range: Full-scale current and pulse widths can be tuned programmatically to balance battery consumption against penetration depth and optical sensitivity.
• On-Chip Thermal Calibration: Integrated temperature sensor continuously tracks thermal drift across the internal LEDs and silicon die, allowing firmware to calibrate baseline offsets dynamically.

Common Applications

• Optical Smoke & Fire Detection: Building early-stage fire alarm systems, duct smoke monitoring, and smart home hazard safety detectors.
• Airborne Dust & Aerosol Monitoring: Air purifier inlet sensing, HVAC clean-room filtration monitoring, and particulate matter concentration trend analysis.
• Proximity & Gesture Sensing: Short-range non-contact presence detection, paper path tracking in printers, and object counting on conveyor lines.
• Photoplethysmography (PPG) & Pulse Oximetry: Experimental biomedical research, heart rate (HR) tracking, and oxygen saturation (SpO2) estimation.
• Industrial Fluid Turbidity: In-line testing of liquid clarity, particulate suspension, and sedimentation tracking in chemical or water-filtration piping.

Usage Tips & Pinout Configuration

• Standard Breakout Pinout:
  • VIN: Power Input (3.3V to 5.0V DC if on-board regulator is present; 1.8V if wiring directly to bare sensor lines).
  • GND: Ground (Tie to microcontroller common ground).
  • SDA / SCL: I2C Data and Clock lines. Ensure 4.7 kΩ pull-up resistors are present to the 3.3V bus rail.
  • INT: Active-Low Open-Drain Interrupt Output. Pulls LOW when FIFO hits threshold, new data is ready, or ambient light saturation occurs. (Requires a 10 kΩ pull-up resistor to logic voltage).
• Smoke vs. Dust Distinction:
  • Measure the ratio of Red back-scatter to Infrared back-scatter. Fine combustion particles (smoke) scatter shorter wavelengths (Red/Green) significantly more than longer wavelengths (IR).
  • Large dust and lint particles reflect Red and IR wavelengths almost equally, providing a reliable signature to suppress false smoke alarms.
• Optical Enclosure & Baffling:
  • When designing custom 3D printed enclosures, print the interior sensor chamber in Matte Black filament to absorb internal reflections.
  • Maintain an internal optical baffle or separator between the emitter and photodetector window to avoid direct light leak through the cover glass.
• Firmware Configuration:
  • For particle and smoke detection, run the sensor in Multi-LED Mode at 400 Hz to 1000 Hz sample rate with a 411 μs pulse width to maximize ADC resolution (18-bit) and detection sensitivity.
  • Set the average sample filter to 4× or 8× in firmware to smooth out high-frequency electrical noise and vibration artifacts.