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

• Using uVGA-II(SGC) module from 4D Systems to generate video
• 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

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?
  • Small adapter PCB?
  • Mod each shield with straight pins aiming down?
• Pads on audio jack could be a bit larger to make it easier to inspect soldering
• Audio Enable is actually an OUTPUT from the module, not an input like the datasheet says
  • Rev. 2 should remove the two solder jumper sets from this pin, but retain the LED for Audio On
• Audio On, RX, and TX LEDs are all backwards (on = idle), need to hook them up to +3.3v instead of GND and flip them
• Can't get audio working at all
  • Left support request for 4D, suspect a bug/mis-documentation in the module
• LEDs for TX/RX are dim, should change to the ones used on the MultiSerial shield for part commonality and because they work better
• Spacing on the two GPIO headers doesn't work well, shrouded ones won't fit and two IDC ribbon connectors side by side won't fit and it blocks the microSD slot
  • Be careful on layout as the microSD card slot on the VGA module needs to be accessible