Grove - Gesture V1.0

Introduction

The sensor on Grove - Gesture is PAJ7620U2 that integrates gesture recognition function with general I2C interface into a single chip. It can recognize 9 basic gestures ,and these gestures information can be simply accessed via the I2C bus.

Application: You can use Gesture as an input device to control another grove, or a computer, mobile phone, smart car, robot, and more with a simple swipe of your hand.

Features

Built-in proximity detection
Various main boards support : Arduino UNO/Seeeduino/Arduino Mega2560
9 Basic gestures
Up
Down
Left
Right
Forward
Backward
Clockwise
Count Clockwise
Wave

Tip

More details about Grove modules please refer to Grove System

Specification

Spec Name	Value
Sensor	PAJ7620U2
Power supply	5V
Ambient light immunity	< 100k Lux
Gesture speed in Normal Mode	60°/s to 600°/s
Gesture speed in Gaming Mode	60°/s to 1200°/s
Interface type IIC interface	up to 400 kbit/s
Operating Temperature	-40°C to +85°C
Dimensions	20 * 20mm
Detection range	5-10cm

With Arduino/Seeeduino

Suggest Reading for Starter - Download Arduino and install Arduino driver - Getting Started with Seeeduino/Arduino

Hardware Installation

Grove products have a eco system and all have a same connector which can plug onto the Base Shield. Connect this module to the I2C port of Base Shield, however, without Base Shield, you can also connect Grove - Gesture to Arduino directly by jumper wires.

Arduino UNO	Base Shield	Grove - Gesture
5V	I2C port	VCC
GND	I2C port	GND
SDA	I2C port	SDA
SCL	I2C port	SCL
Digit 2	Not connected	INT (Reserved pad)

INT：Gesture detection interrupt flag mask. You can connect INT pad to digit 2 of Arduino by using jumper wire.

Below image shows how to plug Grove - Gesture onto the I2C port of Base shield

Then plug Base shield onto the Arduino UNO

Gesture Library

We have created a library to help you start playing quickly with the Seeeduino/Arduino, in this section we’ll show you how to set up the library and introduce some of the functions.

Setup

Download the library code as a zip file from the Gesture_PAJ7620 github page.
Unzip the downloaded file into your …/arduino/libraries.
Rename the unzipped folder “Gesture”(or:”Gesture_PAJ7620”)
Start the Arduino IDE (or restart if it is open).

Simple Demo

The following simple demo will show you a very easy application: When you move up, the red led will be turned on, otherwise the red led will be turned off.

#include <Wire.h>
#include "paj7620.h"

void setup()
{
  paj7620Init();
}

void loop()
{
    uint8_t data = 0;  // Read Bank_0_Reg_0x43/0x44 for gesture result.

    paj7620ReadReg(0x43, 1, &data);  // When different gestures be detected, the variable 'data' will be set to different values by paj7620ReadReg(0x43, 1, &data).

    if (data == GES_UP_FLAG)        // When up gesture be detected,the variable 'data' will be set to GES_UP_FLAG.
        digitalWrite(4, HIGH);      // turn the LED on (HIGH is the voltage level)
    if (data == GES_DOWN_FLAG)      // When down gesture be detected,the variable 'data' will be set to GES_DOWN_FLAG.
        digitalWrite(4, LOW);       // turn the LED off by making the voltage LOW

Description of functions

These are the most important/useful function in the library, we invite you to look at the .h and .cpp files yourself to see all the functions available.

1.Initialize the gesture sensor chip PAJ7620

void setup()
{
  paj7620Init();
}

This initialization code should be added to each demo.

2.Read data from PAJ7620 register via I2C - paj7620ReadReg(uint8_t addr, uint8_t qty, uint8_t data[]) - addr: Register address - qty: Number of data to read, addr continuously increase. - data[]: The starting address(a variable or array) to store data.

 void loop()
 {
    uint8_t data = 0;  // Read Bank_0_Reg_0x43/0x44 for gesture result.

    paj7620ReadReg(0x43, 1, &data);  // When different gestures be detected, the variable 'data' will be set to different values by paj7620ReadReg(0x43, 1, &data).

    if (data == GES_UP_FLAG)                            // When up gesture be detected,the variable 'data' will be set to GES_UP_FLAG.
        digitalWrite(4, HIGH);                          // turn the LED on (HIGH is the voltage level)
    if (data == GES_DOWN_FLAG)                      // When down gesture be detected,the variable 'data' will be set to GES_DOWN_FLAG.
         digitalWrite(4, LOW);                          // turn the LED off by making the voltage LOW
 }

We define some register data of gesture, refer to the following table.

Gesture	Register Data	Register Address	If Yes	If Not
Up	data==GES_UP_FLAG	0x43	Gesture detected	No gesture detected
Down	data==GES_DOWN_FLAG	0x43	Gesture detected	No gesture detected
Left	data==GES_LEFT_FLAG	0x43	Gesture detected	No gesture detected
Right	data==GES_RIGHT_FLAG	0x43	Gesture detected	No gesture detected
Forward	data==GES_FORWARD_FLAG	0x43	Gesture detected	No gesture detected
Backward	data==GES_BACKWARD_FLAG	0x43	Gesture detected	No gesture detected
Clockwise	data==GES_CLOCKWISE_FLAG	0x43	Gesture detected	No gesture detected
Count Clockwise	data==GES_COUNT_CLOCKWISE_FLAG	0x43	Gesture detected	No gesture detected
Wave	data==GES_WAVE_FLAG	0x44	Gesture detected	No gesture detected

Gesture Examples/Applications

These examples are going to show you how to recognize gestures from this Grove - Gesture.]

Open File->Examples->Gesture(or:Gesture_PAJ7620)->example->paj7620_9gestures sketch for a complete example.

Description: This example can recognize 9 gestures and output the result, including move up, move down, move left, move right, move forward, move backward, circle-clockwise, circle-counter clockwise, and wave. You also can use Gesture as an input device to control another grove, or a computer, mobile phone, smart car, robot, and more with a simple swipe of your hand.

Note

When you want to recognize the Forward/Backward gestures, your gestures’ reaction time must less than GES_ENTRY_TIME(0.8s). You also can adjust the reaction time according to the actual circumstance.

/*
Notice: When you want to recognize the Forward/Backward gestures, your gestures' reaction time must less than GES_ENTRY_TIME(0.8s).
        You also can adjust the reaction time according to the actual circumstance.
*/

#define GES_REACTION_TIME       500 // You can adjust the reaction time according to the actual circumstance.
#define GES_ENTRY_TIME          800 // When you want to recognize the Forward/Backward gestures, your gestures' reaction time must less than GES_ENTRY_TIME(0.8s).
#define GES_QUIT_TIME           1000

Following are the main program used in the demo:

void setup()
{
    uint8_t error = 0;

    Serial.begin(9600);
    Serial.println("\nPAJ7620U2 TEST DEMO: Recognize 9 gestures.");

    error = paj7620Init();          // initialize Paj7620 registers
    if (error)
    {
        Serial.print("INIT ERROR,CODE:");
        Serial.println(error);
    }
    else
    {
        Serial.println("INIT OK");
    }
    Serial.println("Please input your gestures:\n");
}

void loop()
{
    uint8_t data = 0, data1 = 0, error;

    error = paj7620ReadReg(0x43, 1, &data);             // Read Bank_0_Reg_0x43/0x44 for gesture result.
    if (!error)
    {
        switch (data)                                   // When different gestures be detected, the variable 'data' will be set to different values by paj7620ReadReg(0x43, 1, &data).
        {
            case GES_RIGHT_FLAG:
                delay(GES_ENTRY_TIME);
                paj7620ReadReg(0x43, 1, &data);
                if(data == GES_FORWARD_FLAG)
                {
                    Serial.println("Forward");
                    delay(GES_QUIT_TIME);
                }
                else if(data == GES_BACKWARD_FLAG)
                {
                    Serial.println("Backward");
                    delay(GES_QUIT_TIME);
                }
                else
                {
                    Serial.println("Right");
                }
                break;
            case GES_LEFT_FLAG:
                delay(GES_ENTRY_TIME);
                paj7620ReadReg(0x43, 1, &data);
                if(data == GES_FORWARD_FLAG)
                {
                    Serial.println("Forward");
                    delay(GES_QUIT_TIME);
                }
                else if(data == GES_BACKWARD_FLAG)
                {
                    Serial.println("Backward");
                    delay(GES_QUIT_TIME);
                }
                else
                {
                    Serial.println("Left");
                }
                break;
            case GES_UP_FLAG:
                delay(GES_ENTRY_TIME);
                paj7620ReadReg(0x43, 1, &data);
                if(data == GES_FORWARD_FLAG)
                {
                    Serial.println("Forward");
                    delay(GES_QUIT_TIME);
                }
                else if(data == GES_BACKWARD_FLAG)
                {
                    Serial.println("Backward");
                    delay(GES_QUIT_TIME);
                }
                else
                {
                    Serial.println("Up");
                }
                break;
            case GES_DOWN_FLAG:
                delay(GES_ENTRY_TIME);
                paj7620ReadReg(0x43, 1, &data);
                if(data == GES_FORWARD_FLAG)
                {
                    Serial.println("Forward");
                    delay(GES_QUIT_TIME);
                }
                else if(data == GES_BACKWARD_FLAG)
                {
                    Serial.println("Backward");
                    delay(GES_QUIT_TIME);
                }
                else
                {
                    Serial.println("Down");
                }
                break;
            case GES_FORWARD_FLAG:
                Serial.println("Forward");
                delay(GES_QUIT_TIME);
                break;
            case GES_BACKWARD_FLAG:
                Serial.println("Backward");
                delay(GES_QUIT_TIME);
                break;
            case GES_CLOCKWISE_FLAG:
                Serial.println("Clockwise");
                break;
            case GES_COUNT_CLOCKWISE_FLAG:
                Serial.println("anti-clockwise");
                break;
            default:
                paj7620ReadReg(0x44, 1, &data1);
                if (data1 == GES_WAVE_FLAG)
                {
                    Serial.println("wave");
                }
                break;
        }
    }
    delay(100);
}

In your own project, you may need multi-gestures instead of a single gesture to realise one function , welcome to share!

Resources

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