NEW!!! 2 higher resolutions implemented: NTSC 426x200 and PAL 500x240 in 256 colours!!!

#### What is it?

This is the next generation of my Video Display Shield.

This Arduino 4xVideo Display Shield provides up to 4 analog composite video display outputs with integrated frame buffer memory accessible through SPI. The 4 video outputs are accessible through 1 RCA connector and 1 VGA DB15-HD connector that uses the red, green and blue channels for the composite signal. A VGA to RCA video cable can be ordered with the board. It is also available as single video output option. There is a NTSC version with a 3.579545MHz crystal or a PAL version with 4.43618MHz crystal available. Currently 4 resolutions are implemented: NTSC 320x200 with 256 colours NTSC 426x200 with 256 colours PAL 300x240 with 256 colours PAL 500x240 with 256 colours The heart of this design is the VLSI VS23S040 chip, which is able to output composite video with resolutions from 320x200 in 65536 colours to 720x576 in 4 colours. The chip has a 4x 1Mbit framebuffer, unused memory can be used for graphics tiles, which can be copied into the image data by the internal fast memory block move hardware.

2 IOs of the VS23S040 chip are routed to the HSYNC/VSYNC pins of the VGA connector, to enable an experimental VGA display in the future. There is no guarantee for this to work and no software is available for this mode at the moment. Please contact me for further details.

A 16Mbit (16MByte) SPI FLASH memory is available on-board. It is pre-loaded with a character bitmap consisting of 94 character ( ASCII code 33-126), a bouncing ball demo and a demo image. A SOIC-8 footprint for a I2C EEPROM is also on board, but not populated.

The board uses the Arduino IOREF voltage to translate between 3.3V on the shield side and the respective IO voltage on the Arduino side. So this schield works together with UNO, MEGA, DUE and also with any 3.3V system that uses the Arduino formfactor and pinout, without modifications. In addition a Adafruit Feather compatible pin header can be populated to tap into a 2nd universe of development boards. The board is smaller at the RCA and VGA connector end to expose the IO pin underneath when plugged into a MEGA form factor board.

To make the board compatible to the hardware SPI interfaces on the Arduino Mega and Due, the SPI interface is connected through the ICSP header. The only disadvantage is, that the Video4 board has to be the 1st board in a board stack to access the ICSP header. There is an option to add 3x 0 Ohm resistors and remove the ICSP header to use the shield at a different stack location. See user guide for details.

The board can also be used as a Feather Wing. A special set of connectors can be ordered, which I will be soldering on the board. The Feather controller board needs to have male pin header on its bottom to be able to mount to this wing configuration. See pictures for details.

Specifications:

• Operating supply voltage 4.5V - 20V
• Board IO voltage (IOREF) 1.65V - 5.5V
• 4x Composite Video Output
• Maximum resolution 720x576 in 4 colours
• Implemented resolutions: NTSC 320x200 with 256 colours NTSC 426x200 with 256 colours PAL 300x240 with 256 colours PAL 500x240 with 256 colours
• Crystal: NTSC 3.579545MHz or PAL 4.43618MHz
• Communication interface: SPI up to 38MHz
• Video Frame Buffer: 4x1Mbit = 512KByte
• Flash: 16Mbit = 2MByte
• EEPROM: up to 2Mbit (optional, not populated)
• IO connectors Arduino Uno and Adafruit Feather compatible
• Size: 85mm x 53mm (3.3" x 2.1")

#### Why did you make it?

I wanted to provide an upgraded device to provide full format display capabilities to the Arduino/Feather world and make use of all the analog video displays and composite video inputs that are still available on every LCD TV.

#### What makes it special?

This is a video card for Arduino with 4 outputs, that uses a dedicated framebuffer + hardware to generate the video signal. This keeps the controller free for its main tasks and does display updates through fast SPI transfers. There are a lot of solutions out there that use the microcontroller itself and its internal timing and memory peripherals for video signal generation. Those take valuable resource and computing power away from the microcontroller.