Composite Video Graphics: Scramble Arduino Arcade

Building a game on a tiny OLED screen is one thing. Outputting real analog composite video signals directly into a massive 50-inch CRT television using nothing but an Arduino Uno is absolute programming black magic. The Scramble Arcade (8-bit) project utilizes the TVout library, forcing the Uno to completely hijack its internal processor timing to mathematically draw 8-bit scanlines 60 times a second!

The NTSC/PAL Sync Signal Physics (TVout)

A TV expects a terrifyingly precise analog electrical signal perfectly synchronized at 15.7kHz.

1. The Uno does not have a video card. It has 2 kilobytes of RAM!
2. The TVout.h library assigns two specific Pins (Sync=Pin 9, Video=Pin 7).
3. The Custom DAC Resistors: You must physically solder a 470 Ohm resistor to the Sync pin and a 1000 Ohm resistor to the Video pin, merging them into the center pin of a Yellow RCA cable. This mathematically creates a raw, primitive Digital-to-Analog converter!
4. The Uno creates an invisible 128 x 96 pixel shadow-buffer in its SRAM, consuming nearly 50% of the entire microcontroller's memory instantly!

The Scramble Game Engine Array

Because the video processing takes almost the entire processor core, the game logic must be ruthlessly optimized.

• The player’s spaceship is a tiny byte matrix PROGMEM sprite.
• The scrolling terrain (the hardest part of Scramble) is an array of height integers pointing into drawing mathematically calculated vertical lines TV.drawLine(x, startY, x, endY, WHITE);.
• The Execution Frame-Rate: TV.delay(1) is not a normal delay(). It physically waits for the exact moment the electron beam on the massive TV finishes painting the bottom of the screen (the V-BLANK phase)!
• The Uno then violently calculates collision physics and inputs exactly during that microscopic invisible blink, preventing tearing!

Analog Entertainment Hardware

• Arduino Uno/Nano (Mega is rarely supported, as TVout relies on highly specific ATmega328 Timer1 hardware architecture).
• A massive vintage CRT Television or a modern TV with the Yellow Composite Video RCA input.
• Resistors (470 Ohm & 1K Ohm) to manually forge the analog video signals!
• A generic RCA Video Cable (You must physically cut the cable with scissors, stripping it to find the internal signal wire and the outer ground shielding mesh!).
• Arcade Joystick components.