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I got my HYDRA Book--A few questions... — Parallax Forums

I got my HYDRA Book--A few questions...

VaatiVaati Posts: 712
edited 2009-08-07 04:34 in Propeller 1
I got my HYDRA book + dip prop today--the book is massive!!

Reading through it, I noticed that the video pins for the HYDRA are different than that of the demo board...· How would I change the pins so the video basepin is pin 12?· I don't understand why it just says "%011_0000" for pins in the tvparams...

Also, I only have 5MHz crystals, and it seems as though all of the HYDRA stuff uses a 10MHz crystal...· Is there any way to make it so I don't have to buy another part?

I had also ordered an rca to breadboard adpater, and not the DAC resistors.· Is it possible to use potentiometers and a multimeter to ensure it is the correct resistance?


Lastly, I want to compliment Andre LaMothe for the excellent book.· I can't wait to use some of my super metroid sprite .bmp's...· smurf.gif


Thanks.

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Quit buying all those fixed voltage regulators, and·get an Adjustable Power Supply·for your projects!· Includes an LED testing terminal!

*-NEW-* SD Card Adapter·Now available!· Add extra memory to your next Propeller project with ease!

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2009-08-05 21:54
    1) Yes, the video pins for the Hydra are different from those used on the Demo Board. The start method for most of the TV (and VGA) drivers is passed the first I/O pin used and adjusts everything else to fit.

    2) The Hydra uses a 10MHz crystal and PLL8X which yields the same system clock frequency (80MHz) as the Demo Board. Just change _XINFREQ and _CLKMODE to match what you have and the code should adjust itself. That's why there are functions like CLKFREQ.

    3) What are you going to use the RCA to breadboard adapter for? The proper resistor values are shown on the Demo Board schematic.
  • VaatiVaati Posts: 712
    edited 2009-08-05 22:07
    I was planning to use the rca to breadboard adapter with my propmodule and/or my propstick kit. smile.gif

    So, what would I do to change the video basepin to pin 12? With tv_text, I ususally just put "text.start(12)" and it works fine...


    Thanks.

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Quit buying all those fixed voltage regulators, and·get an Adjustable Power Supply·for your projects!· Includes an LED testing terminal!

    *-NEW-* SD Card Adapter·Now available!· Add extra memory to your next Propeller project with ease!
  • Mike GreenMike Green Posts: 23,101
    edited 2009-08-05 23:37
    There's a block of comments at the end of TV.SPIN that explains the values of various parameters to it. tv_pins is the one you want. Bits 6..4 specify the group of 8 pins used for video generation. The code goes up to %111 for pins 55..63 for the planned 64 I/O pin Propeller that hasn't materialized. For pins 15..8, use %001. Bits 3..0 define several things including whether the upper 4 bits or lower 4 bits of the I/O pin group is used. You probably want %0100. If you need S-Video output, you should use %0110 (see the comments for details).

    tv_text.spin takes care of this for you. Look at the graphics demo for an example of having the TV parameters in the main program and passing that to TV.SPIN.
  • Bob Lawrence (VE1RLL)Bob Lawrence (VE1RLL) Posts: 1,720
    edited 2009-08-07 04:34
    You can use the link below to view/print a Propeller I/O Comparison Chart . On page 18.

    It compares the following:

    Propeller Proto Board – 5Mhz
    Propeller Demo Board – 5Mhz
    Hydra Gamer Board – 10Mhz
    PropRPM Board – 5Mhz

    "The Propeller I/O Comparison Chart: (used with permission)
    Created by: George K. Herzog"

    ucontroller.com/Propeller%20Protoboard%20Designs%20for%20the%20Beginner.pdf

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    Aka: CosmicBob
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