AM312 Mini IR Infrared PIR Body Motion Human Sensor

AM312 Mini Passive Infrared Motion Sensor — 3.3V/5V

The AM312 is a miniature PIR motion sensor module that fits into spaces too small for the standard HC-SR501. It detects human body movement up to 3 metres away with a 100° detection cone, and its 2.7V–12V supply range makes it one of the few PIR modules that works directly with 3.3V microcontrollers like ESP8266 and ESP32 without a level shifter or voltage divider. The output goes high for approximately 2 seconds on detection, then returns low automatically.

• 2.7V–12V supply range — works at 3.3V (ESP32, ESP8266) and 5V (Arduino)
• Up to 3 metre detection range — 100° horizontal detection cone
• 2-second output pulse on detection — high output, then auto-reset
• Compact 10 x 23mm PCB — fits into enclosures where HC-SR501 is too large
• Fresnel lens included — press-fit over the sensor dome

How does the AM312 compare to the HC-SR501?

The AM312 is smaller, operates at 3.3V directly, and is simpler — no sensitivity or timing potentiometers to configure. The HC-SR501 offers longer range (7m vs 3m), adjustable sensitivity, and a retriggerable mode. Choose the AM312 for ESP32 projects, tight enclosures, or when you need minimal configuration; choose the HC-SR501 when you need longer range or adjustable timing.

Can the AM312 trigger on pets?

Yes, PIR sensors cannot distinguish humans from animals by movement alone. Animals smaller than 20kg typically produce weaker IR signatures that may fall below the detection threshold, but larger pets trigger the AM312 reliably. If false triggers from pets are a concern, mount the sensor above 1.5 metres pointing downward — most animals crouch lower than humans.

Best for

ESP32 motion-activated lights, ESP8266 IoT presence sensors, battery-powered alarm triggers, corridor night lights, smart home occupancy detection, small enclosure builds, and 3.3V microcontroller projects where the HC-SR501 cannot be used directly.

Why Kunkune

Shipped from UK stock. 60-day returns, no minimum order. Fast Royal Mail delivery.

For longer detection range and adjustable sensitivity, the HC-SR501 PIR sensor covers up to 7 metres with a potentiometer-controlled range and hold time.

Buying in bulk? For orders of 10+ units, contact us for trade pricing.