Pier 42 4x Video Display Shield Gives Your Arduino or Feather Board Four Composite Video Outputs
https://www.hackster.io/news/pier-42-4x-video-display-shield-gives-your-arduino-or-feather-board-four-composite-video-outputs-98a98c8434b2

Built around the VLSI VS23S040, this smart add-on offers four dedicated display outputs — complete with independent frame-buffer memory.

Electronic engineer Wolfgang Friedrich has launched a display add-on for Arduino Uno and Feather form-factor microcontroller boards which give them an impressive four composite video outputs — complete with integrated frame-buffers for each.

“There is a NTSC version with a 3.579545MHz crystal or a PAL version with 4.43618MHz crystal available. Currently 2 resolutions are implemented: NTSC 320×200 with 256 colors PAL 300×240 with 256 colors.”

In theory, the board supports up to 720×576 resolution per display, though at just four colors; this mode is not yet implemented, however, alongside the potential for VGA compatibility on the DB15-HD connector — though “there is no guarantee for this to work,” Friedrich warns, “and no software is available for this mode at the moment.”

The board is designed as an Arduino Shield, compatible with the Arduino Uno, Due, Mega, and other microcontrollers which share the same form factor and pinout. Interestingly, the same board is also compatible with microcontrollers which follow the Adafruit Feather layout — using an unpopulated-by-default second set of pin headers to accept any Feather board in place of an Arduino.

The 4x Video Display Shield is now available on the Pier 42 Tindie store at $35 for a single-output variant and $39 for the full four-output version; the Feather Wing headers can be supplied for an additional $3.

Source files for the board are available on GitHub under an unspecified license, with further information on the board design available on the project’s Hackaday.io page

https://hackaday.io/project/170499-vga-shield-wing

While most analog televisions come with composite video inputs on a yellow RCA jack, the feature is not universal. This problem was even more prevalent in the 1980s, and most home consoles got around the problem by instead feeding video to the television’s tuner with an RF modulator. [Manzel Seet] had just such a television which used the PAL standard. Wanting to display images from a microcontroller, he put together PAL-Streamer.

The aim of the project was to display images on an analog television with minimal investment in hardware over and above what [Manzel] already had on hand. To this end, the project was built using a STM32F411 Nucleo development board. Capable of running at clock speeds up to 100 MHz, there’s plenty of grunt to handle demanding tasks like outputting video signals to a TV.

https://hackaday.io/project/171977-pal-streamer

Outputting a Video Signal From a Microcontroller’s GPIO Pins — Through Square-Wave Harmonics
https://www.hackster.io/news/outputting-a-video-signal-from-a-microcontroller-s-gpio-pins-through-square-wave-harmonics-a42c99e52137

Taking advantage of higher-order harmonics, Manzel Seet’s PAL Streamer can output valid video signals from slower microcontrollers.

Student engineer Manzel Seet has demonstrated how to create a video output from a microcontroller’s general-purpose input/output (GPIO) pins with no external components — by using pulse-width modulation (PWM) to generate analog TV signals.

“I wanted to make a simple & cheap analog TV transmitter from parts I had lying around,” Seet explains of the project’s origins. “I searched online and I came across @CNLohr avr_vhf project. He used an AVR ATtiny85 to generate PWM waveforms which were picked up by his TV.”

uses an STM32F446RE microcontroller to generate composite video signals

An Arduino Uno with TVout library is used to create a Pong clone playable on TV. The Pong code is written by Peter Lamonica and it is downloadable here: http://pastebin.com/L2PZSdNb I just added simple audio commands to create game sound on TV audio input

The two Pong paddles are driven by 10 kOhm potentiometers inserted in two metallic boxes.

Using a digital pin, shifting out a signal at 80 MHz to broadcast analog tv to an analog tv on channel 3. Whooh! Github: http://github.com/cnlohr/channel3 I was playing around with the I2S bus on the ESP8266 and found that it could output the I2S port at 80 MHz and still maintain the DMA!

Apart from Arduino and a cable with male RCA connector, you need a DAC (Digital To Analog Converter) of 2-bits. It’s very easy to construct simply with two resistors of 330 Ohm and 1 kOhm