ESP32 Dino Run (Part 3): Random Obstacles, Levels, and Screen Inversion

Отandibond

Upgrade your DIY console: bring your game to life with sound effects and save your best results in the ESP32 memory.

In the first and second parts, we taught our Dino how to jump and save high scores. However, the gameplay was predictable: cacti appeared at regular intervals. In this final part, we will transform our prototype into a true hardcore runner where every attempt is unique.

What’s New in Version v1.3?

The main goal of this update is unpredictability. Now, players can’t just memorize the rhythm; they must react to the situation in real-time.

  • True Random Distance: We have implemented a random number generator. The gap between cacti is now always different.
  • Progressive Density: Starting from Level 2, the maximum spawn delay is reduced—cacti fly at you much faster and in tighter groups.
  • Variable Height: Obstacles now have a random height (from 8 to 15 pixels), forcing the player to time their jumps more precisely.
  • Visual Shock (Inversion): Upon reaching Level 3 (30 points), the screen instantly inverts, creating a «Night Mode» effect and increasing the difficulty.

Wiring Diagram

A quick reminder of the pinout. For sound effects, make sure to use a passive buzzer.

Important: A 100–220 Ohm resistor between GPIO 25 and the positive (+) terminal of the buzzer is required to limit the current and avoid overloading the ESP32 port.

Buzzer Type: The code uses the tone() function, so a passive buzzer is best (it allows you to change the pitch). An active buzzer will only beep at a single fixed note.

ComponentPin (Display/Button)ESP32 Pin (GPIO)Description
OLED DisplayVCC3.3VPower Supply
OLED DisplayGNDGNDCommon Ground
OLED DisplaySCLGPIO 22I2C Clock Line
OLED DisplaySDAGPIO 21I2C Data Line
ButtonPin 1GPIO 15Jump Signal
ButtonPin 2GNDGround Connection
BuzzerVia 100 Ohm resistorGPIO 25Audio Signal Output
BuzzerNegative (-)GNDCommon Ground

Wokwi Simulation: Testing Without Hardware

Before picking up a soldering iron, I recommend testing everything in an online simulator. This saves time on debugging.

Try the game in your browser:

Link to Wokwi Project

Key Mechanics Breakdown (v1.3)

True Randomness

To ensure the random() function produces different values every time you power on the device, we initialize it using noise from an unused analog pin:

randomSeed(analogRead(0));

Level-Based Spawn Logic

We have implemented a reduction of the «wait window» as the level increases. This creates the feeling that more obstacles are appearing:

int maxSpawnDelay = (level >= 2) ? 40 : 90;
obstacleX = 128 + random(0, maxSpawnDelay);

Full Source Code: ESP32 Dino Run v1.3 (by AndiBond)

Copy and paste this code into your Arduino IDE.

#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Preferences.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define BUZZER_PIN 25
#define BUTTON_PIN 15

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);
Preferences preferences;

// Game Parameters
int dinoY = 45;
int velocity = 0;
int gravity = 2;
bool isJumping = false;
int obstacleX = 128;
int score = 0;
int highScore = 0;

// Difficulty Parameters
int gameSpeed = 7;      
int obstacleWidth = 6;  
int obstacleHeight = 10; 
int level = 1;
bool inverted = false; 

// Function Prototypes
void showStartScreen();
void handleGameOver();
void drawGame();
void playSound(int freq, int duration);

void setup() {
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  pinMode(BUZZER_PIN, OUTPUT);
  randomSeed(analogRead(0)); // Initialize randomness
  
  if(!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    for(;;);
  }

  preferences.begin("dino-game", false);
  highScore = preferences.getInt("highscore", 0);
  
  showStartScreen();
}

void playSound(int freq, int duration) {
  tone(BUZZER_PIN, freq, duration);
}

void loop() {
  // 1. INPUT
  if (digitalRead(BUTTON_PIN) == LOW && !isJumping) {
    velocity = -12;
    isJumping = true;
    playSound(600, 80);
  }

  // 2. PHYSICS
  if (isJumping) {
    dinoY += velocity;
    velocity += gravity;
    if (dinoY >= 45) {
      dinoY = 45;
      isJumping = false;
    }
  }

  // LEVEL LOGIC
  level = (score / 10) + 1;
  gameSpeed = 6 + level; 

  // Inversion at Level 3 (30 points)
  if (level >= 3 && !inverted) {
    inverted = true;
    display.invertDisplay(true); 
    playSound(400, 200); delay(100); playSound(800, 200); 
  }

  obstacleX -= gameSpeed; 

  // Obstacle Spawning
  if (obstacleX < -20) {
    score++;
    
    // Random distance: denser at level 2+
    int maxSpawnDelay = (level >= 2) ? 40 : 90;
    obstacleX = 128 + random(0, maxSpawnDelay); 
    
    // Random height
    obstacleHeight = random(8, 16);
    
    if (score % 10 == 0) playSound(1200, 50); 
  }

  // Collision Check
  if (obstacleX > 15 && obstacleX < 25 && dinoY > (55 - obstacleHeight)) {
    handleGameOver();
  }

  drawGame();
  delay(30); 
}

void showStartScreen() {
  inverted = false;
  display.invertDisplay(false); 
  display.clearDisplay();
  display.setTextColor(WHITE);
  display.setTextSize(1);
  display.setCursor(25, 5);
  display.print("DINO RUN ESP32");
  display.setCursor(18, 18);
  display.print("v1.3 by AndiBond");
  display.setCursor(28, 38);
  display.print("HI-SCORE: ");
  display.print(highScore);
  display.setCursor(20, 54);
  display.print("Press to Start");
  display.display();

  while(digitalRead(BUTTON_PIN) == HIGH) { delay(10); }
  playSound(800, 100);
  delay(200); 
}

void handleGameOver() {
  playSound(150, 600);
  if (score > highScore) {
    highScore = score;
    preferences.putInt("highscore", highScore);
  }
  
  display.clearDisplay();
  display.setCursor(10, 10);
  display.setTextSize(2);
  display.print("GAME OVER");
  display.setTextSize(1);
  display.setCursor(15, 35);
  display.print("Score: "); display.print(score);
  display.print("  Lv: "); display.print(level);
  display.setCursor(30, 50);
  display.print("HI-Score: "); display.print(highScore);
  display.setCursor(30, 57);
  display.print("andibond.com");
  display.display();
  
  delay(2500);
  score = 0;
  obstacleX = 128;
  dinoY = 45;
  showStartScreen(); 
}

void drawGame() {
  display.clearDisplay();
  display.setTextSize(1);
  display.setCursor(0, 0);
  display.print("L:"); display.print(level);
  display.setCursor(35, 0);
  display.print("S:"); display.print(score);
  display.setCursor(80, 0);
  display.print("HI:"); display.print(highScore);
  
  display.drawLine(0, 55, 128, 55, WHITE);
  display.fillRect(20, dinoY, 10, 10, WHITE); 
  display.fillRect(obstacleX, 55 - obstacleHeight, obstacleWidth, obstacleHeight, WHITE);
  
  display.display();
}
  • ESP32 Dino Run levels
    • ESP32 Dino Run levels

    AndiBond.com

    Conclusion

    We have come a long way from drawing a single dot on the screen to creating a fully functional game with:

    • Jump physics and gravity.
    • A high score system in Non-Volatile Storage (NVS).
    • Sound feedback.
    • Random level generation.

    Project v1.3 by AndiBond is a great foundation for your own modifications. Try adding flying bird enemies or speed-up power-ups!

    Share your high scores in the comments and subscribe to stay tuned for new DIY guides!

    Missed the previous parts?

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