PAL Graphics Demo. How?
I am· trying to put the Graphics Demo to work.
It is giving me·a garbled picture, a mess of white and black pixels.There is something moving behind the picture so it seems that something is·actually being sent to the TV.
Apparently my TV set is multi-standard but anyway I would like to try PAL mode.
How do I set PAL mode in the Graphics Demo program ?
By the way, I am using a 20Mhz crystal and have changed the clock settings to:
_clkmode = xtal1 + pll4x
_xinfreq = 20_000_000
To connect the Propeller to the TV set I am using the schematics provided·by Phil Pilgrim for the PropStick: 3 resistors connected to pins A12, A13 and A14.
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Post Edited (inaki) : 5/7/2006 11:42:52 AM GMT
It is giving me·a garbled picture, a mess of white and black pixels.There is something moving behind the picture so it seems that something is·actually being sent to the TV.
Apparently my TV set is multi-standard but anyway I would like to try PAL mode.
How do I set PAL mode in the Graphics Demo program ?
By the way, I am using a 20Mhz crystal and have changed the clock settings to:
_clkmode = xtal1 + pll4x
_xinfreq = 20_000_000
To connect the Propeller to the TV set I am using the schematics provided·by Phil Pilgrim for the PropStick: 3 resistors connected to pins A12, A13 and A14.
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Post Edited (inaki) : 5/7/2006 11:42:52 AM GMT
Comments
It is giving me·a garbled picture, a mess of white and black pixels.There is something moving behind the picture so it seems rotating dots.
I am using a CineVision LCD display sold by Radio Shack.
To make PAL video, you must change the 4th long in the tvparams structure to %0001. That LSB selects NTSC or PAL generation.
tvparams··············· long··· 0·············· 'status
······················· long··· 1·············· 'enable
······················· long··· %001_0101······ 'pins
······················· long··· %0000·········· 'mode - CHANGE THIS TO %0001
······················· long··· 0·············· 'screen
······················· long··· 0·············· 'colors
······················· long··· x_tiles········ 'hc
······················· long··· y_tiles········ 'vc
······················· long··· 10············· 'hx
······················· long··· 1·············· 'vx
······················· long··· 0·············· 'ho
······················· long··· 0·············· 'vo
······················· long··· 55_250_00···· · 'broadcast
······················· long··· 0·············· 'auralcog
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Chip Gracey
Parallax, Inc.
Is your crystal 10MHz or less? 5MHz is ideal. You've got to be clocking at at least 40MHz for this to work properly. Also, if you are using a series-resonant crystal, it's frequency will be off by just enough to kill the color lock.
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Chip Gracey
Parallax, Inc.
I don't understand that.
If I use a 20Mhz crystal would not be enough to change the clock settings to multiply by 4X instead of 16x?
_clkmode = xtal1 + pll4x
_xinfreq = 20_000_000
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The PLL ALWAYS multiplies by 16. It's just that we can select which stage we get the output from.
Maybe the docs need to be a bit more clear on this.
(Never use the PLL with a Xtal of more than 10MHz?)
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Don't visit my new website...
Now I get a decent picture but I get a lot of noise too. Colors are not solid.
This noise problem might be the cable perhaps ? I am using an RCA video cable with the 3 resistors soldered on one end.
The other end is connected to a scart connector on the TV set.
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All the tv or video programs does not work in my breadboard, the ones using LEDS all work.
I am using 5 Mhz crystal the one recommended in this forum.
I have seen two versions of the resistor networks, one with three resistors and one with four resistors (the one shown in your demo board).
Which one is the correct one or both work?
Chip Gracey
Parallax, Inc.