GS20 Gesture Recognizer Sensor (YS4009)

Introduction

The GS20 is a high-performance, non-contact gesture recognition module powered by the advanced YS4009 sensor. Unlike traditional infrared sensors, the YS4009 contains image sensor, DSP processing, and MCU, utilizes a sophisticated image-based algorithm to provide superior stability and high-speed detection.

Capable of recognizing 8 distinct hand gestures, the GS20 offers an intuitive touch-free interface for smart home systems, robotics, and interactive DIY projects. Its compact form factor and I2C PH2.0 4-Pin interface ensure seamless integration with Arduino, ESP32, and Raspberry Pi platforms.

Key Features

• Powered by YS4009: High-precision CMOS imaging technology for accurate gesture tracking.
• 8 Gesture Support: Detects Up, Down, Left, Right, Forward, Backward, Hover and Leave.
• Plug-and-Play: PH2.0 4-Pin connector prevents reverse polarity and simplifies wiring.
• I2C Interface: Standard I2C communication with a 3.3V/5V logic level shifter onboard, address 0x39.

Technical Specifications

Parameter	Specification
Core Chip	YS4009
Operating Voltage	DC 5.0V
Communication	I2C (Address: 0x39)
Sensing Distance	25 - 35 cm (10 - 14")
Connector Type	PH2.0 4-Pin
Dimensions	22.4mm x 38.4mm

Hardware Overview & Pinout

Pin	Name	Description
1	GND	Ground
2	VCC	Power Supply (5V)
3	SCL	I2C Serial Clock Line
4	SDA	I2C Serial Data Line

Getting Started (Arduino Example)

Hardware Connection

Connect the GS20 to your Arduino Uno R3 board using the following mapping:

GS20 Module	Arduino Uno R3
GND	GND
VCC	VCC
SCL	SCL(A5)
SDA	SCA(A4)

Library Installation

1. Click here download the arduino library

2. In the Arduino IDE, go to Sketch -> Include Library -> Add .ZIP Library... and select the downloaded .zip file.

3. Click here to view descriptions of classes and interfaces

Example

Arduino

#include <Arduino.h>
#include <String.h>
#include <Wire.h>

// include
#include <gesture_recognizer.h>

namespace {
// create GestureRecognizer instance, I2C address 0x39 (GestureRecognizer::kDefaultI2cAddress)
emakefun::GestureRecognizer g_gesture_recognizer(emakefun::GestureRecognizer::kDefaultI2cAddress);
}  // namespace

void setup() {
  Serial.begin(115200);
  Serial.println("setup");
  Wire.begin();
  const auto ret = g_gesture_recognizer.Initialize(&Wire);
  if (ret == 0) {
    Serial.println(String(F("gesture recognizer initialization was successful")));
  } else {
    Serial.println(String(F("gesture recognizer initialization failed: ")) + ret);
    while (true);
  }
  Serial.println(F("setup was successful"));
}

void loop() {
  // get gesture 
  const auto gesture = g_gesture_recognizer.GetGesture();
  // If the gesture is not empty, print the value of the gesture.
  if (gesture != emakefun::GestureRecognizer::kGestureNone) {
    Serial.println(String(F("recognized gesture: ")) + gesture);
  }
}

Micropython

Click here download the micropython library

from gesture_recognizer import GestureRecognizer
import machine

print("setup")
gesture_recognizer = GestureRecognizer(i2c=machine.I2C(0, sda=21, scl=22),
                                       i2c_address=0x39)
print("version:", gesture_recognizer.version)
gesture_dict = {
    GestureRecognizer.GESTURE_NONE: "gesture none",
    GestureRecognizer.GESTURE_RIGHT_SWIPE: "gesture right swipe",
    GestureRecognizer.GESTURE_LEFT_SWIPE: "gesture left swipe",
    GestureRecognizer.GESTURE_BACKWARD_SWIPE: "gesture backward swipe",
    GestureRecognizer.GESTURE_FORWARD_SWIPE: "gesture forward swipe",
    GestureRecognizer.GESTURE_UPWARD: "gesture upward",
    GestureRecognizer.GESTURE_DOWNWARD: "gesture downward",
    GestureRecognizer.GESTURE_OUT_OF_RANGE: "gesture out of range",
    GestureRecognizer.GESTURE_HOVER: "gesture hover",
}

print("loop")
while True:
    gesture = gesture_recognizer.gesture
    if gesture is not GestureRecognizer.GESTURE_NONE:
        print(gesture_dict[gesture])

Best Practices & Troubleshooting

• Operating Range: For best results, keep your hand about 25cm from the sensor.
• Upward Gesture: Hover at a low position for 200ms, then move upward within the sensing zone.
• Downward Gesture: Hover at a high position for 200ms, then move downward to trigger.
• Power-on Setup: Keep the sensor clear for 300ms after startup and install acrylic covers before powering on.

Resources & Support

Module 3D file

Module Dimensional Drawing