Introduction to Pixy2 Camera

The Pixy2 camera is a powerful and versatile tool for developers, hobbyists, and educators looking to incorporate computer vision capabilities into their projects. This compact camera module offers a range of features, including object detection, color tracking, barcode reading, and line tracking, making it an ideal choice for robotics, automation, and interactive applications.

Key Features of Pixy2 Camera

1. Object Detection: Pixy2 can detect and track objects based on their color signatures, allowing for easy identification and localization of specific items in the camera’s field of view.
2. Barcode Reading: The camera is capable of reading various types of barcodes, including QR codes, making it useful for inventory management and information retrieval applications.
3. Line Tracking: Pixy2 can detect and follow lines, enabling the creation of line-following robots or autonomous vehicles.
4. Compact Size: Measuring just 1.75″ x 1.75″ x 1.4″, the Pixy2 camera is small enough to be integrated into a wide range of projects without taking up too much space.
5. Easy Integration: The camera communicates via SPI, I2C, or UART, making it compatible with popular development boards such as Arduino, Raspberry Pi, and BeagleBone.

How Pixy2 Camera Works

Object Detection and Color Tracking

Pixy2 uses a color-based filtering algorithm to detect and track objects. Users can train the camera to recognize specific objects by defining their color signatures. The camera then continuously analyzes the incoming video feed, identifying and reporting the positions of the detected objects in real-time.

The object detection process can be broken down into the following steps:

1. Image Acquisition: Pixy2 captures images using its onboard camera sensor.
2. Color Filtering: The captured images are processed using the predefined color signatures, isolating the objects of interest.
3. Object Localization: The camera determines the positions of the detected objects within the image frame.
4. Data Output: The object data, including position and size, is sent to the host device via one of the supported communication protocols.

Barcode Reading

Pixy2 is equipped with a barcode reading engine that allows it to detect and decode various types of barcodes, such as:

• QR Codes
• DataMatrix Codes
• Code 128
• Code 39
• Interleaved 2 of 5

The barcode reading process involves the following steps:

1. Barcode Detection: Pixy2 scans the image for the presence of barcodes.
2. Barcode Decoding: Once a barcode is detected, the camera attempts to decode the information contained within it.
3. Data Output: The decoded barcode data is sent to the host device for further processing or display.

Line Tracking

Pixy2’s line tracking capability enables it to detect and follow lines, making it useful for creating line-following robots or autonomous vehicles. The camera uses a combination of edge detection and color-based filtering to identify and track lines.

The line tracking process can be summarized as follows:

1. Image Acquisition: Pixy2 captures images of the environment containing the lines to be tracked.
2. Edge Detection: The camera applies edge detection algorithms to identify the boundaries of the lines.
3. Color Filtering: Color-based filtering is used to isolate the lines from the background, ensuring accurate tracking.
4. Line Following: Pixy2 continuously reports the position and orientation of the detected lines, allowing the host device to control the robot or vehicle accordingly.

Interfacing Pixy2 with Arduino

One of the most popular ways to use Pixy2 is by interfacing it with an Arduino board. This combination allows for the creation of interactive projects that leverage the camera’s computer vision capabilities.

Hardware Setup

To connect Pixy2 to an Arduino, you will need the following components:

• Pixy2 camera
• Arduino board (e.g., Arduino Uno)
• Jumper wires

The connection between Pixy2 and Arduino can be established using the SPI interface. Follow these steps to set up the hardware:

1. Connect the Pixy2’s MOSI pin to the Arduino’s MOSI pin (pin 11 on Arduino Uno).
2. Connect the Pixy2’s MISO pin to the Arduino’s MISO pin (pin 12 on Arduino Uno).
3. Connect the Pixy2’s SCK pin to the Arduino’s SCK pin (pin 13 on Arduino Uno).
4. Connect the Pixy2’s SS pin to the Arduino’s pin 10.
5. Connect the Pixy2’s GND pin to the Arduino’s GND pin.
6. Connect the Pixy2’s 5V pin to the Arduino’s 5V pin.

Software Setup

To start using Pixy2 with Arduino, you will need to install the Pixy2 Arduino library. Follow these steps to set up the software:

1. Open the Arduino IDE.
2. Go to Sketch > Include Library > Manage Libraries.
3. Search for “Pixy2” in the library manager.
4. Install the “Pixy2” library by charmedlabs.
5. Include the Pixy2 library in your Arduino sketch using #include <Pixy2.h>.

Example Arduino Sketch

Here’s a simple Arduino sketch that demonstrates how to use Pixy2 for object detection:

#include <Pixy2.h>

Pixy2 pixy;

void setup() {
  Serial.begin(115200);
  pixy.init();
}

void loop() {
  int i;
  pixy.ccc.getBlocks();

  if (pixy.ccc.numBlocks) {
    Serial.print("Detected ");
    Serial.print(pixy.ccc.numBlocks);
    Serial.println(" objects:");

    for (i = 0; i < pixy.ccc.numBlocks; i++) {
      Serial.print("  Object ");
      Serial.print(i);
      Serial.print(": X=");
      Serial.print(pixy.ccc.blocks[i].m_x);
      Serial.print(", Y=");
      Serial.println(pixy.ccc.blocks[i].m_y);
    }
  }

  delay(100);
}

This sketch initializes the Pixy2 camera, detects objects in the camera’s field of view, and prints the number of detected objects along with their X and Y coordinates to the serial monitor.

Applications of Pixy2 Camera

Pixy2’s versatile features make it suitable for a wide range of applications, including:

1. Robotics: Pixy2 can be used for object tracking, line following, and color-based navigation in robotic projects.
2. Autonomous Vehicles: The camera’s line tracking and object detection capabilities can be utilized in the development of small-scale autonomous vehicles.
3. Inventory Management: By leveraging Pixy2’s barcode reading functionality, businesses can automate inventory tracking and management processes.
4. Interactive Installations: Pixy2 can be used to create interactive art installations that respond to the presence or movement of specific objects or colors.
5. Educational Projects: The camera’s easy integration and diverse features make it an excellent tool for teaching computer vision concepts and encouraging STEM learning.

Comparison with Other Computer Vision Cameras

Here’s a comparison table highlighting the key features of Pixy2 and other popular computer vision cameras:

Feature	Pixy2	OpenMV	JeVois-A33	RealSense D435
Resolution	320×200	640×480	1920×1080	1280×720
Object Detection	Yes	Yes	Yes	Yes
Color Tracking	Yes	Yes	No	No
Barcode Reading	Yes	Yes	No	No
Line Tracking	Yes	No	No	No
Depth Sensing	No	No	No	Yes
Interface	SPI, I2C, UART	USB	USB	USB 3.0
Price Range	$50-$60	$65-$75	$100-$120	$180-$200

As evident from the comparison table, Pixy2 stands out with its unique combination of features, including color tracking, barcode reading, and line tracking, at an affordable price point.

Frequently Asked Questions (FAQ)

1. Q: What is the resolution of the Pixy2 camera?
   A: Pixy2 has a resolution of 320×200 pixels.

2. Q: Can Pixy2 detect multiple objects simultaneously?
   A: Yes, Pixy2 can detect and track multiple objects in real-time based on their color signatures.

3. Q: Is Pixy2 compatible with Raspberry Pi?
   A: Yes, Pixy2 can be interfaced with Raspberry Pi using SPI, I2C, or UART communication protocols.

4. Q: Can Pixy2 read QR codes?
   A: Yes, Pixy2 is capable of detecting and decoding QR codes, along with other popular barcode formats.

5. Q: How do I train Pixy2 to recognize specific objects?
   A: Objects can be trained using the Pixy2’s color signature feature. You can use the PixyMon software to define color signatures for the objects you want to detect.

Conclusion

Pixy2 is a powerful and versatile camera module that brings computer vision capabilities to a wide range of projects. With its object detection, color tracking, barcode reading, and line tracking features, Pixy2 enables developers, hobbyists, and educators to create innovative applications in robotics, automation, and interactive systems.

The camera’s compact size, easy integration, and compatibility with popular development boards make it an accessible tool for users of all skill levels. Whether you are building a line-following robot, automating inventory management, or creating an interactive art installation, Pixy2 provides a reliable and cost-effective solution for incorporating computer vision into your projects.