coelamon / arduino-tvout

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Arduino 8MHZ sync problems #80

Open GoogleCodeExporter opened 8 years ago

GoogleCodeExporter commented 8 years ago
What is the expected output? What do you see instead?
As many have stated before, the TVout doesn't run well on an 8mhz arduino

What version of the product are you using? On what operating system?
TVoutBeta1
MacOs 10.9
Arduino Lilypad (atmega238P)
8MHZ crystal

Please provide any additional information below.

As already mentioned before: the build is quite stabile on 40x36 pixels, but I 
didn't really want to lose resolution so with a lot of trial and error I have 
achieved the following result:

http://cl.ly/image/2Z2o0N2A1s34/DSC_0023.JPG

The image doesn't glitch anymore and everything runs at a nice speed. But now 
every second line rendered is moved towards the right creating a second 'ghost' 
image.

The only things I have changed in the code is the video_properties.h:

//Timing settings for PAL
#define _PAL_TIME_SCANLINE          64
#define _PAL_TIME_OUTPUT_START      19

#define _PAL_LINE_FRAME             220
#define _PAL_LINE_START_VSYNC       0
#define _PAL_LINE_STOP_VSYNC        8
#define _PAL_LINE_DISPLAY           130

Lowering the PAL_LINE_FRAME value improves image stability by a lot.

Now I'm not an expert in Arduino programming and I honestly have no idea what I 
am doing besides changing values in the various files, but any help would be 
appreciated, how I could get these two images on top of each other, or perhaps 
remove one of them.

Original issue reported on code.google.com by j.p.L...@gmail.com on 3 Feb 2014 at 3:41