SmartElex BX604 PIR Motion Sensor Module

🚶 SmartElex BX604 PIR Motion Sensor Module — Technical Information
🔍 Overview
The SmartElex BX604 PIR Motion Sensor Module is a compact, ultra-low power passive infrared (PIR) motion detector designed to detect human movement based on infrared radiation changes.
Detects:
Motion of warm bodies (humans/animals)
Output:
Digital HIGH/LOW signal
Designed for:
Battery-powered and low-power motion sensing systems
👉 It is optimized for energy-efficient and compact embedded applications.
⚙️ Working Principle
🔥 Passive Infrared (PIR) Detection
1. 🌡️ IR Radiation Monitoring
Human body emits infrared radiation
Sensor detects changes in IR levels, not constant temperature
2. 🧠 Pyroelectric Sensing Element
Uses a pyroelectric infrared sensor
Generates electrical signal when IR radiation changes
3. 🔄 Differential Detection
Detects movement across sensing zones
Motion → changing IR pattern → trigger signal
4. 📡 Digital Processing
Internal circuit:
Amplifies signal
Converts to digital output
👉 Outputs HIGH when motion is detected.
📊 Detection Characteristics
Detection range: up to 12 meters
Detection angle: ~120° (horizontal)
Detection Behavior
Sensitive to:
Human movement
Warm object motion
Requires motion (no detection of static objects)
⚡ Electrical Characteristics
Operating voltage: 2.2V to 3.7V
Power consumption:
< 11 µA (ultra-low standby current)
👉 Ideal for battery-powered devices.
🔗 Output Interface
Digital Output
HIGH → Motion detected
LOW → No motion
Output Behavior
Motion triggers a timed HIGH signal
Returns to LOW after delay
🧠 Internal Features
✔ Integrated Digital Processing
Converts PIR signal → stable digital output
Reduces external circuitry requirement
✔ Ultra-Low Power Design
Designed for:
Long battery life
Always-on sensing
✔ Fresnel Lens Support
Uses external Fresnel lens (SB-F-02):
Improves detection range
Expands sensing coverage
✔ Compact Sensor Window
Small 4 × 4 mm sensing area
🔄 Operating Behavior
✔ Motion Detection
Detects changes in infrared radiation
Output goes HIGH when motion occurs
✔ Stabilization Time
Requires short time after power-up to stabilize
✔ Repeat Detection
Can retrigger if motion continues
🌡️ Environmental Characteristics
Works best at:
Indoor temperature conditions
Affected by:
Ambient temperature
Airflow
IR interference
⚠️ Limitations
Cannot detect:
Stationary objects
Performance reduced when:
Ambient temperature ≈ human body temperature
Sensitive to:
Rapid temperature changes
Requires lens for full performance
🔌 Typical Pin Configuration
VCC → 2.2–3.7V supply
GND → Ground
OUT → Digital output
🧩 Functional Role
The module acts as a:
Motion detection sensor
Presence trigger device
Low-power automation sensor
🏁 Summary
The SmartElex BX604 PIR Sensor is a compact, ultra-low power motion detection module that:
Uses passive infrared (PIR) sensing
Detects motion up to 12 meters with 120° coverage
Provides digital HIGH/LOW output
Consumes extremely low power (<11 µA)
Is ideal for battery-powered IoT and automation systems