5 Pieces HC-SR501 PIR Motion Detector Sensor Module — Adjustable Sensitivity & Delay, 3.3V Output, Arduino Compatible

Name: 5 Pieces HC-SR501 PIR Motion Detector Sensor Module — Adjustable Sensitivity & Delay, 3.3V Output, Arduino Compatible
Brand: Envistia
Price: 8.89 USD
Availability: InStock

$8.89

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Detect motion instantly with the HC-SR501 PIR Motion Detector Sensor Module — the most popular passive infrared sensor for Arduino, ESP32, and Raspberry Pi projects. It detects the infrared heat signature of people, animals, and other warm objects up to 7 meters (21 feet) away across a 120° detection cone, and outputs a clean 3.3V digital signal that any microcontroller can read directly. Two onboard potentiometers let you adjust sensitivity and time delay, and a jumper selects between single and repeatable trigger modes.

Three wires, no libraries, no calibration — just connect 5V, GND, and read the output pin. When motion is detected, the output goes HIGH. When it stops, the output goes LOW. It's that simple.

⚡ Key Features

Wide detection range: 3m to 7m (9ft to 21ft), adjustable via onboard sensitivity potentiometer.
Wide detection angle: ~120° cone from the Fresnel lens — covers an entire room or hallway.
Adjustable time delay: 3 seconds to 5 minutes — set how long the output stays HIGH after detection.
Dual trigger modes: Jumper-selectable Single (L) or Repeatable (H) trigger. Repeatable mode keeps the output HIGH as long as motion continues — ideal for automatic lighting.
Simple digital output: 3.3V HIGH when motion detected, 0V LOW when no motion. Compatible with 3.3V and 5V logic — no level shifting needed.
Wide operating voltage: 5V to 20V DC — works with USB, batteries, and a wide range of power supplies.
Ultra-low power: Only 65µA quiescent current — ideal for battery-powered projects.
No libraries needed: Uses a single digitalRead() — works immediately with basic Arduino code.
Compact: 32mm × 24mm PCB with 23mm Fresnel lens dome.

🔧 How It Works

The HC-SR501 uses a pyroelectric sensor behind a Fresnel lens to detect changes in infrared radiation. When a warm object (person, pet, vehicle) moves across the sensor's field of view, the change in IR energy triggers the BISS0001 signal processing IC, which outputs a clean digital HIGH signal.

Detects: Moving warm objects — people, animals, warm vehicles.
Does NOT detect: Stationary objects, objects behind glass (glass blocks IR), or objects at the same temperature as the background.
Does NOT measure: Distance, direction, speed, or number of people — it's a simple motion yes/no sensor.

📌 Pinout

Pin	Label	Connect To	Function
1	VCC	5V – 20V DC	Power supply. Output is always 3.3V regardless of supply voltage.
2	OUT	Digital pin (e.g., D2)	3.3V HIGH = motion detected, 0V LOW = no motion.
3	GND	Ground	Common ground with your microcontroller.

Note: Pin order may vary between manufacturers. Always check the silkscreen labels on your specific module.

🔧 Onboard Adjustments

Control	Function	Range
Sensitivity pot	Detection range	~3m to ~7m (CW = more sensitive)
Time delay pot	Output HIGH duration	~3 seconds to ~5 minutes (CW = longer)
Trigger jumper	Trigger mode	L = Single trigger, H = Repeatable trigger

🎯 Perfect For

Automatic lighting — hallway, bathroom, closet, porch, and stairway lights
Security alarms — trigger buzzers, sirens, or notifications on motion
Smart home / Home Assistant — connect via ESP32 or Pi for automations
Occupancy detection — HVAC control, energy saving, meeting room availability
People counting — approximate count using single trigger mode
Pet detection — automatic feeders, pet doors, activity monitoring
Halloween props — trigger animatronics, sound effects, or lighting
Wildlife cameras — activate a camera when an animal passes by
Automatic fan control — turn on ventilation when someone enters a room
Arduino & STEM projects — teach digital input, sensor integration, and automation

📐 Specifications

Sensor type: Passive Infrared (PIR), pyroelectric
Processing IC: BISS0001
Operating voltage: 5V – 20V DC
Quiescent current: ~65µA
Output signal: Digital — HIGH = 3.3V, LOW = 0V
Detection range: 3m – 7m (adjustable)
Detection angle: ~120° cone
Time delay: 3 seconds – 5 minutes (adjustable)
Blockage time: ~2.5 seconds after each trigger cycle
Trigger modes: Single (L) / Repeatable (H), jumper selectable
Warm-up time: 30–60 seconds after power-up
Operating temperature: −15°C to +70°C
PCB dimensions: 32mm × 24mm (1.27" × 0.96")
Lens diameter: 23mm (Fresnel lens)

🔌 Compatible With

Arduino Uno, Mega, Nano, Leonardo — direct connection, read with any digital pin
ESP32 / ESP8266 — 3.3V output is safe for ESP GPIO. Power from VIN or external 5V (not 3.3V rail)
Raspberry Pi — 3.3V output is safe for Pi GPIO. Power from 5V pin
STM32, AVR, PIC, and any microcontroller with a digital input
Standalone — output can directly drive a small LED, relay module, or buzzer without a microcontroller

📦 Package Contents

5 × (5 Pieces) HC-SR501 PIR Motion Detector Sensor Module (with Fresnel lens installed)

Arduino, jumper wires, breadboard, and power supply are not included.

💡 Tip — Reducing False Triggers: If you experience random activations, add a 10µF–100µF electrolytic capacitor and a 0.1µF ceramic capacitor across the VCC and GND pins directly at the sensor. This filters power supply noise and is the single most effective fix. Full details in our User Guide.