PAJ7620U2 Gesture Recognition Sensor Module – 9 Hand Gestures, I2C Interface, Smart Control

Description

The PAJ7620U2 is an integrated gesture recognition sensor module from PixArt Imaging, designed to enable touchless human-machine interaction. It combines an infrared LED, an optical lens, and a 30×30 pixel sensor array in a compact package, recognizing hand gestures by tracking the movement of a single object (such as a hand) within its sensing field .

The module supports up to 9 basic gestures in its standard gesture mode: move Up, Down, Left, Right, Forward, Backward, Clockwise, Counter-clockwise, and Wave . It operates via a standard I2C interface (7-bit address 0x73), requiring only two signal pins for communication . An interrupt (INT) pin is also provided for gesture event notification .

A key advantage of the PAJ7620U2 is its built-in infrared LED and optical lens, allowing it to work reliably in low-light and dark environments . It also features high ambient light immunity (up to 100k Lux), making it suitable for use in normally lit rooms . The module operates from 3.3V or 5V (with onboard voltage translation on most breakout boards) and has a typical detection range of 5cm to 15cm (up to 20cm per the manufacturer) .

In addition to gesture mode, the sensor supports a cursor mode that outputs real-time position, size, and brightness data of the tracked object, and a proximity detection mode . This makes it versatile for applications beyond simple gesture commands.

Critical limitations: The PAJ7620U2 recognizes single-object gestures only—it cannot track multiple hands simultaneously . Recognition accuracy depends on the speed and clarity of the gesture; fast or ambiguous movements may not be detected reliably. The “Forward” and “Backward” gestures (z-axis movement) are noted as more difficult to trigger consistently compared to planar movements . For applications requiring more complex gesture combinations, custom algorithm logic must be implemented on the host microcontroller .

Features

• 9 Built-in Gestures: Up, Down, Left, Right, Forward, Backward, Clockwise, Counter-clockwise, Wave .

• I2C Interface: Simple two-wire communication (SDA/SCL) with interrupt support .

• Works in Darkness: Integrated IR LED and lens enable operation in low-light conditions .

• High Ambient Light Immunity: Reliable operation up to 100k Lux .

• Cursor Mode: Outputs real-time position, size, and brightness data of tracked objects .

• Proximity Mode: Detects presence and approximate distance of objects .

• Fast Recognition Rate: 240Hz report rate for responsive gesture detection .

• Wide Compatibility: 3.3V/5V logic level support (onboard translator on most modules) .

Technical Specifications