Lesson 19

Color Recognition (Hiwonder 7.4)

Use the ESP32-S3 Vision Module to Recognize Red/Blue and React

🎯 Learning Objectives

• Understand the “two brains” setup: ESP32-S3 vision module does detection, Arduino reads results over I2C
• Recognize red and blue blocks and trigger different robot behaviors
• Learn what a “color ID array” is and how to interpret it (255 = nothing detected)
• Use the RGB LED and buzzer for feedback
• Follow safe upload workflow notes (remove Bluetooth module to avoid serial conflicts)

✅ Before You Start (Plug-and-Play After Lesson 18)

Lesson 18 proved the camera and hotspot work. For Lesson 19, you will switch the ESP32-S3 from “live feed” firmware (7.3) to “color recognition” firmware (7.4). After you do this, the live-stream page behavior may change—that’s expected.

🎨 Section 1: What This Program Does

In Hiwonder 7.4, the miniAuto uses the ESP32-S3 vision module to recognize red and blue blocks. When a color is detected, the robot reacts and the RGB LED shows the matching color.

Expected Outcomes

• Red detected: RGB turns red, buzzer beeps once, robot rocks forward/back
• Blue detected: RGB turns blue, buzzer beeps twice, robot rocks left/right
• Nothing detected: RGB turns white

Safety Note (from Hiwonder)

🧠 Section 2: Reading Color IDs (Concept)

The ESP32-S3 processes the image and exposes results over I2C. The Arduino reads a small buffer/array. If a color is detected, the corresponding slot will contain a color ID. If nothing is detected, the value is usually 255.

Pseudo-Logic

// Read detection results into a buffer
readColorBuffer(buffer);

if (buffer[0] == 1) {
  // red
  setRgb(RED);
  beep(1);
  rockForwardBackward();
} else if (buffer[2] == 3) {
  // blue
  setRgb(BLUE);
  beep(2);
  rockLeftRight();
} else {
  setRgb(WHITE);
}

🔧 Hands-On Activity: Color Reaction Demo

Test the robot’s reactions with real red and blue blocks.

Checklist

📋 Assessment & Homework

Programming Challenges

Research Assignment

Practical Exercises