Pier 42 4x Video Display Shield Gives Your Arduino or Feather Board Four Composite Video Outputs
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.
"This Arduino 4x Video Display Shield provides up to 4 analog composite video display outputs with integrated frame buffer memory accessible through SPI," Friedrich explains of the design. "The four 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."
"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 320x200 with 256 colors PAL 300x240 with 256 colors."
The board is built around VLSI VS23S040 chips, alongside SPI RAM split into four 1MB frame-buffer memories - one per possible display. A 16Mb SPI flash provides storage for display content, pre-loaded with a 94-character bitmap, a Commodore Amiga-inspired "boing-ball" demo animation, and a static image.
In theory, the board supports up to 720x576 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.