Shop OBEX P1 Docs P2 Docs Learn Events
PropGFX not working — Parallax Forums

PropGFX not working

blittledblittled Posts: 681
edited 2011-08-06 08:32 in Propeller 1
I have built a breadboard version of the PropGFX using two breadboards. The PropGFX breadboard has an RCA Breakout wired to P12-P14 with the appropriate resistors. I did replace the 1.1K with a 1K. It also has a 24LC512 chip for 64K of EEPROM and 5MHz crystal. The host board has Sparkfun's FTDI232RL breakout board in 3.3V mode with a NPN transistor inverter on DTR going to reset and I'm using it to power the 3.3V rail on both breadboards. It has a 24LC256, 5MHz crystal and a momentary spst switch between ground and reset.

The two Props have P0-P9 and Reset tied together. The transmit and receive are jumpered to the appropriate Prop to upload to the Prop.

When I run the Chip's Graphics Demo it works flawlessly but when I upload the PropGFX binary using H.A.M. or Ariba's method I get no video signal.

1. Is the 1.1K resistor critical? I would think it would just change the hue slightly.
2. Does this require more current than the FTDI232RL can supply?
3. Any other reason?

Comments

  • Oldbitcollector (Jeff)Oldbitcollector (Jeff) Posts: 8,091
    edited 2011-08-03 20:12
    Hmm..

    1.1k vs 1k shouldn't be critical.

    Perhaps a decription of my own setup, *might* help.

    I'm using two Protoboards. P0-P9 connected between the two.
    I didn't bother with connecting the reset lines together.
    On the PropGFX board I'm using a standard three resistor video configuration.
    I've also tied the Ground and voltage lines together

    Each board has it's own USB connection so I've programmed the propGFX board, then switched to the other.

    I'm guessing that you have a bad connection between the data lines of the two boards.

    OBC
  • blittledblittled Posts: 681
    edited 2011-08-04 17:56
    I solved my problem. The FTDI232RL was not providing enough current. When I added a 7.5V DC adapter through a regulator it worked! The host propeller works as well. I did add a 100 Ohm resistor in series with the 1K to get 1.1K and I also added 10K resistors to the SCL lines of the eeproms.
  • Oldbitcollector (Jeff)Oldbitcollector (Jeff) Posts: 8,091
    edited 2011-08-04 19:00
    Duh, Re-reading my original post before coffee, I meant that the 1.1k vs 1k shouldn't have been a critical issue. Either way, I'm pleased that you have it working. (and perfect video as well!)

    (Stupid fingers don't always type what the brain tells them to..) Welcome to the PropGFX club!

    OBC
  • blittledblittled Posts: 681
    edited 2011-08-04 19:22
    @OBC, Thanks for the input. I figured that the 100 Ohm wasn't important since the NTSC standard is pretty forgiving. It was a cinch to add it to the breadboard. Now to add one of my Spin Studio SD Cards and DIN breakouts so I can have FemtoBasic run on it.
  • BaggersBaggers Posts: 3,019
    edited 2011-08-05 03:09
    Welcome to the PropGFX club blittled ;D glad you got it sorted, I was out of town yesterday, so didn't see this!
  • BaggersBaggers Posts: 3,019
    edited 2011-08-06 08:32
    @blittled, any chance of changing the thread title ? :)
Sign In or Register to comment.