HC-SR501 PIR Motion Sensor

The HC-SR501 uses a pyroelectric sensor behind a Fresnel lens to detect body heat moving across its 110° field of view. When it sees motion its output goes HIGH for an adjustable time, so it can switch a relay or wake a microcontroller without any code. Two potentiometers set range (3–7 m) and delay (≈ 3 s – 5 min), and a jumper selects single or repeat triggering.

Key features

• Detection range adjustable from about 3 to 7 m, 110° cone
• Adjustable output time from ≈ 3 s to 5 min
• Repeat or single trigger mode
• Digital 3.3 V output, 5–20 V supply

Specifications

What's in the box

• 1 × HC-SR501 module with lens

Ideal for

• Automatic lighting
• Intruder alarms
• Occupancy-based energy saving

Good to know

• Allow about 1 minute warm-up after power-on before readings are stable.