Circuit Documentation

Summary

This circuit is designed to play a simple Pong game using an Arduino UNO microcontroller, an OLED 128x64 I2C Monochrome Display, and two pushbuttons. The Arduino UNO controls the game logic and interfaces with the OLED display over I2C to render the game graphics. The pushbuttons are used to control the player's paddle in the game.

Component List

Arduino UNO

• Description: A microcontroller board based on the ATmega328P.
• Purpose: Acts as the central processing unit for the Pong game, handling input, game logic, and display output.

OLED 128x64 I2C Monochrome Display

• Description: A small graphical OLED display with I2C interface.
• Purpose: Displays the Pong game graphics, including paddles, ball, and score.

Pushbutton (x2)

• Description: A simple tactile switch that provides a digital input to the microcontroller.
• Purpose: Serves as the user interface for controlling the player's paddle in the game.

Wiring Details

Arduino UNO

• 5V connected to OLED Display VDD
• GND connected to OLED Display GND
• SCL connected to OLED Display SCK
• SDA connected to OLED Display SDA
• D7 connected to both Pushbutton Pin 2 (in)
• D3 connected to Pushbutton Pin 3 (out)
• D2 connected to Pushbutton Pin 3 (out)

OLED 128x64 I2C Monochrome Display

• VDD connected to Arduino UNO 5V
• GND connected to Arduino UNO GND
• SCK connected to Arduino UNO SCL
• SDA connected to Arduino UNO SDA

Pushbutton 1

• Pin 2 (in) connected to Arduino UNO D7
• Pin 3 (out) connected to Arduino UNO D3

Pushbutton 2

• Pin 2 (in) connected to Arduino UNO D7
• Pin 3 (out) connected to Arduino UNO D2

Documented Code

/*
  A simple Pong game.
  https://notabug.org/Maverick/WokwiPong
  
  Based on Arduino Pong by eholk
  https://github.com/eholk/Arduino-Pong
*/

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

#define UP_BUTTON 2
#define DOWN_BUTTON 3

const unsigned long PADDLE_RATE = 64;
const unsigned long BALL_RATE = 16;
const uint8_t PADDLE_HEIGHT = 12;
const uint8_t SCORE_LIMIT = 9;

Adafruit_SSD1306 display = Adafruit_SSD1306(128, 64, &Wire);

bool game_over, win;

uint8_t player_score, mcu_score;
uint8_t ball_x = 53, ball_y = 26;
uint8_t ball_dir_x = 1, ball_dir_y = 1;

unsigned long ball_update;
unsigned long paddle_update;

const uint8_t MCU_X = 12;
uint8_t mcu_y = 16;

const uint8_t PLAYER_X = 115;
uint8_t player_y = 16;

void setup() 
{
    display.begin(SSD1306_SWITCHCAPVCC, 0x3C);

    // Display the splash screen (we're legally required to do so)
    display.display();
    unsigned long start = millis();

    pinMode(UP_BUTTON, INPUT_PULLUP);
    pinMode(DOWN_BUTTON, INPUT_PULLUP);

    pinMode(7, OUTPUT);
    digitalWrite(7, LOW);

    display.clearDisplay();
    drawCourt();

    while(millis() - start < 2000);

    display.display();

    ball_update = millis();
    paddle_update = ball_update;
}

void loop() 
{
    bool update_needed = false;
    unsigned long time = millis();

    static bool up_state = false;
    static bool down_state = false;
    
    up_state |= (digitalRead(UP_BUTTON) == LOW);
    down_state |= (digitalRead(DOWN_BUTTON) == LOW);

    if(time > ball_update) 
    {
        uint8_t new_x = ball_x + ball_dir_x;
        uint8_t new_y = ball_y + ball_dir_y;

        // Check if we hit the vertical walls
        if(new_x == 0 || new_x == 127) 
        {
            ball_dir_x = -ball_dir_x;
            new_x += ball_dir_x + ball_dir_x;

            if (new_x < 64)
            {
                player_scoreTone();
                player_score++;
            }
            else
            {
                mcu_scoreTone();
                mcu_score++;
            }

            if (player_score == SCORE_LIMIT || mcu_score == SCORE_LIMIT)
            {
                win = player_score > mcu_score;
                game_over = true;
            }
        }

        // Check if we hit the horizontal walls.
        if(new_y == 0 || new_y == 53) 
        {
            wallTone();
            ball_dir_y = -ball_dir_y;
            new_y += ball_dir_y + ball_dir_y;
        }

        // Check if we hit the CPU paddle
        if(new_x == MCU_X && new_y >= mcu_y && new_y <= mcu_y + PADDLE_HEIGHT) 
        {
            mcuPaddleTone();
            ball_dir_x = -ball_dir_x;
            new_x += ball_dir_x + ball_dir_x;
        }

        // Check if we hit the player paddle
        if(new_x == PLAYER_X && new_y >= player_y && new_y <= player_y + PADDLE_HEIGHT)
        {
            playerPaddleTone();
            ball_dir_x = -ball_dir_x;
            new_x += ball_dir_x + ball_dir_x;
        }

        display.drawPixel(ball_x, ball_y, BLACK);
        display.drawPixel(new_x, new_y, WHITE);
        ball_x = new_x;
        ball_y = new_y;

        ball_update += BALL_RATE;

        update_needed = true;
    }

    if(time > paddle_update) 
    {
        paddle_update += PADDLE_RATE;

        // CPU paddle
        display.drawFastVLine(MCU_X, mcu_y, PADDLE_HEIGHT, BLACK);
        const uint8_t half_paddle = PADDLE_HEIGHT >> 1;

        if(mcu_y + half_paddle > ball_y)
        {
            int8_t dir = ball_x > MCU_X ? -1 : 1;
            mcu_y += dir;
        }

        if(mcu_y + half_paddle < ball_y)
        {
            int8_t dir = ball_x > MCU_X ? 1 : -1;
            mcu_y += dir;
        }

        if(mcu_y < 1) 
        {
            mcu_y = 1;
        }

        if(mcu_y + PADDLE_HEIGHT > 53)
        {
            mcu_y = 53 - PADDLE_HEIGHT;
        }

        // Player paddle
        display.drawFastVLine(MCU_X, mcu_y, PADDLE_HEIGHT, WHITE);
        display.drawFastVLine(PLAYER_X, player_y, PADDLE_HEIGHT, BLACK);

        if(up_state) 
        {
            player_y -= 1;
        }

        if(down_state) 
        {
            player_y += 1;
        }

        up_state = down_state = false;

        if(player_y < 1) 
        {
            player_y = 1;
        }

        if(player_y + PADDLE_HEIGHT > 53) 
        {
            player_y = 53 - PADDLE_HEIGHT;
        }

        display.drawFastVLine(PLAYER_X, player_y, PADDLE_HEIGHT, WHITE);

        update_needed = true;
    }

    if(update_needed)
    {
        if (game_over)
        {
            const char* text = win ? "YOU WIN!!" : "YOU LOSE!";
            display.clearDisplay();
            display.setCursor(40, 28);
            display.print(text);
            display.display();

            delay(5000);

            display.clearDisplay();
            ball_x = 53;
            ball_y = 26;
            ball_dir_x = 1;
            ball_dir_y = 1;
            mcu_y = 16;
            player_y = 16;
            mcu_score = 0;
            player_score = 0;
            game_over = false;
            drawCourt();
        }

        display.setTextColor(WHITE, BLACK);
        display.setCursor(0, 56);
        display.print(mcu_score);
        display.setCursor(122, 56);
        display.print(player_score);
        display.display();
    }
}

void playerPaddleTone()
{
    tone(11, 250, 25);
    delay(25);
    noTone(11);
}

void mcuPaddleTone()
{
    tone(11, 225, 25);
    delay(25);
    noTone(11);
}

void wallTone()
{
    tone(11, 200, 25);
    delay(25);
    noTone(11);
}

void player_scoreTone()
{
    tone(11, 200, 25);
    delay