VGA Shield

The VGA Shield will be, as the project name may indicate, an Arduino-compatible shield that outputs VGA video.

Project Status

Schematic and board layout complete, PCBs received, VGA modules received from 4D, parts received from Digikey. First rev. 1 board has been assembled and is working fine video-wise. Testing continues.

Design Overview

• Shield will provide I2C-RS232 bridge so the Arduino doesn't have to use its (only) RS232 UART for this
• Will provide a 3.5mm jack for external speakers (no room on shield for a speaker)
• The µVGA-II(SGC) has 16 GPIOs, so will pin those out on the standard 2x5 connectors
• Status LEDs for power, TX, RX, and audio enabled

Chipset Options

• 4D Systems µVGA-PICASO-MD1 module ($54)
  • Very expensive
  • Some complaints about reliability
  • Only talks RS232

• New 4D Systems uVGA-II(SGC) module ($49)
  • Relatively expensive
  • Only supports up to 800x480 (WVGA) @ 16bpp
  • Very easy to interface with (via an I2C/SPI to RS232 bridge likely)

• Propeller chip with custom code ($8)
  • Cheap
  • Unsure how high resolution would be possible given generating VGA video from an MCU

• Custom FPGA solution ($?)
  • More work than any other solution
  • Similar cost to propeller chip, likely

• Off-the-shelf VGA controller chip
  • The Epson S1D13506 seems promising, you talk to it and it has an internal RAMDAC to generate video.
    • Supports LCD, VGA, and NTSC/PAL composite output
    • Flexible bus to talk to the microcontroller
    • Requires EDO DRAM, which isn't available anymore.
  • The Epson S1D13517 might work, it's like the S1D13506 but takes SDRAM
    • Supports up to 800x600 16bpp
    • Only supports TFT displays, may be able to make it talk DVI though through timings/TMDS converter?

• Project Peacock
  • Hybrid CPLD/MCU solution, cheaper than using a softcore in an FPGA
  • Would allow for an easy DVI shield too

Revision 1 Issues

• Through-holes for all connectors mating with the VGA module are too small!
  • Worked around for rev. 1 by modifying VGA module w/ thinner machine pins
• Serial connector doesn't work well at all, need to figure out a better solution for rev. 2
  • Concave pogo pins?
    • Would add $10 to the shield, eek!
  • Connector on wires?
• Pads on audio jack could be a bit larger to make it easier to inspect soldering