Analog Video Synthesis: Black & White TV Games

Most projects display text on tiny SPI OLED screens. The Composite Video Game Engine achieves the impossible: It forces the tiny 8-bit, 16MHz Arduino Uno processor to synthesize complex analog television signals natively, drawing a retro game of Pong or Tetris directly onto the screen of a massive 1990s CRT television!

The Physics of NTSC/PAL Video Signals

You do not plug a USB cable into a TV. The Arduino must literally "draw" the picture onto the screen line-by-line using precise analog voltage drops and mathematically flawless microsecond timing delays.

1. Standard CRT televisions use a yellow RCA Video Cable.
2. The Voltage Divider: You wire Arduino Digital Pin 7 and Pin 9 together using a 470-ohm and 1K-ohm resistor. This creates a crude 3-step Digital-to-Analog converter!
3. The Synchronization:
   • 0.0 Volts = SYNC Pulse (Tells the TV's electron gun to move to the next horizontal line).
   • 0.3 Volts = Black Pixel.
   • 1.0 Volts = Bright White Pixel.

TVout Library Raster Execution

To generate this terrifyingly exact signal, the <TVout.h> library hijacks the deepest core interrupts of the ATmega328P chip.

1. The microcontroller spends 90% of its processing power frantically spitting out exact 1.0V and 0.3V pulses. It literally draws a 128x96 pixel black-and-white grid onto the massive screen 60 times a second!
2. You only have 10% of the CPU power left to execute your game logic!
3. TV.draw_rect(20, 20, 50, 50, WHITE);
4. The library injects pure white pixels into the video stream buffer, and a brilliant white box appears perfectly stable on the living room television!

Necessary CRT Hardware

• Arduino Uno (Must have incredibly stable 16MHz oscillator crystals).
• Two specific Resistors (470 Ohm and 1K Ohm) to synthesize the video signal voltages.
• An old RCA Yellow Video Cable stripped to its bare copper wires.
• An old CRT Television or modern monitor with RCA Composite inputs.
• Potentiometers or Arcade buttons wired to analog pins to act as the Pong paddles or Joystick!