SmartElex BS612 PIR Motion Sensor Module

🔹 Product Overview
The SmartElex BS612 PIR Motion Sensor Module is a digital passive infrared (PIR) motion detection module that integrates:
Pyroelectric sensing element
Digital signal processing circuit
Electromagnetic shielding
It detects human motion by sensing infrared radiation changes and provides a processed digital output signal.
🔹 Working Principle
Detects infrared radiation variation caused by moving human bodies
Internal circuit converts analog PIR signal → ADC digital signal
When signal exceeds threshold → REL output triggered (motion detected)
🔹 Electrical Characteristics
Operating Voltage: 2.2V – 3.7V
Power Consumption: < 12 µA (ultra-low power)
Designed for low-power and battery-based systems
🔹 Detection Characteristics
Detection Range: Up to 12 meters (with Fresnel lens)
Detection Angle: ~120° (horizontal)
Sensing Window: ~3 × 4 mm
🔹 Output Characteristics
Output Type: Digital (HIGH / LOW)
Signal Name: REL output
Behavior:
HIGH → Motion detected
LOW → No motion
Built-in timing control (pulse output duration)
🔹 Internal Features
Integrated digital signal processing (DSP)
Built-in filtering (noise & RF interference suppression)
High power supply rejection ratio
Stable detection with reduced false triggering
🔹 Functional Pins / Control Features
REL Pin: Digital output signal
OEN (Enable) Pin:
Enables/disables output
Can be used with light sensor for automatic control
External components allow:
Sensitivity adjustment
Delay time adjustment
🔹 Physical Characteristics
Dimensions: ~34 × 11 × 7 mm
Weight: ~3 g
Compact PCB with Fresnel lens
🔹 Key Technical Features
Fully integrated PIR + digital processing
Ultra-low standby current
Wide-angle and long-range detection
Adjustable sensitivity and timing
Electromagnetic shielding for stability
Direct digital interface (no external ADC needed)
🔹 Functional Behavior
Detects motion only (dynamic IR change)
Best detection when motion is across the sensor field
Output includes timed pulse after detection
Internal processing eliminates need for external filtering
🔹 Limitations
Cannot detect stationary objects
Performance affected by:
Ambient temperature
Lens quality
Movement direction and speed
Sensitive to strong IR sources (sunlight, heat emitters)