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Topic: Paint on the TV screen with Arduino (Read 3 times) previous topic - next topic



 I post to the french forum an experiment to interface crt monitors with Arduino.


 The post is in French but you can take a look to the program if you're interested :


Can you briefly explain how you did it in English? I don't speak French at all!




Hello Zitron,

 I'm going to try it in english...

 Please, take a look at the french post for pictures and code.

 First go to this page to uderstand what king of signal we have to generate : http://www.retroleum.co.uk/PALTVtimingandvoltages.html. It was a little bit different in NTSC, you'll have to change some timings to according to the NTSC standard (google is your friend).

 The resistors made a 2 bits DAC (Digital to Analog Converter). I have choose to connect them to the digital ouputs 8 and 9.

 All the code in the loop() function genrate the composite signal according to the PAL standard. The tab memVideo[][] is used as video memory. Each byte of it represent a (big) pixel at screen ; you can video on video by putting _BLACK, _WHITE or _GRAY in a cell of these tab. it was doing by the "switch() case" wich interpret some serial input as command.

 If you want to try these code, you'll have to change the content of the file "wiring.c" which is in "\arduino-0007\lib\targets\arduino". make a copy before you change it to restore it after. The changes to mades are explainded in the "Reply #4" of the french post. The changes are made to stop the millis() and delay() interupt, so can't use them in the program.

 To test these experimentation, you can trace on screen bt using the keypad key 2 4 6 8 to move an invisible cursor, 5 to trace (print ?) and b g n to change color of the pen (b->White n->Black g->Gray). The first line is invisible and the pen is black at start.

 Ask me if you have any question




I'm in the UK so I've got PAL as well. I hooked up my TV tuner, and got a black screen. I thought it wasn't working, but I didn't know that's what I was supposed to get! Now it's kind of working, but I get a lot of scan line looking noise:

The actual pictures looks slightly better than the still image. I disabled and enable interrupts, doesn't seem to make any difference.




really like the painting on screen but it's low res.

what do you think about this high res?


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