Difference between revisions of "VGA Shield"

From Hackstrich
(Issue list.)
(Pogo pins are too expensive.)
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* Serial connector doesn't work well at all, need to figure out a better solution for rev. 2
 
* Serial connector doesn't work well at all, need to figure out a better solution for rev. 2
 
** Concave pogo pins?
 
** Concave pogo pins?
 +
*** Would add $10 to the shield, eek!
 
** Connector on wires?
 
** Connector on wires?
 
* Pads on audio jack could be a bit larger to make it easier to inspect soldering
 
* Pads on audio jack could be a bit larger to make it easier to inspect soldering

Revision as of 07:11, 19 March 2011

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