Creating custom Uzebox

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Kilo
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Re: Creating custom Uzebox

Post by Kilo » Sat Dec 02, 2017 11:59 am

The solution with the MC1377 doesn't work. I guess it's a sync problem. Mh... too bad. Another Atmega TV project gives me vsync and hsync. So the MC1377 works.

But I'm also thinking about a modular version. Where different Joysticks can be use. Solution like the Jamma one.
Also it would be nice to have only one main board where people can add their video output standard i.e. AV, Hdmi, scart etc.
So you can combine your kit with different types of available solutions.
The last digit of Pi is 7! I calculated this, as I counted to infinity yesterday!

CunningFellow
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Re: Creating custom Uzebox

Post by CunningFellow » Sat Dec 02, 2017 7:44 pm

What is the MC1377 not doing? Are you feeding it 3.57Mhz (it needs a different freq to the AD72x). Can you see any signal on its composite output? What does the scope trace look like?

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Kilo
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Re: Creating custom Uzebox

Post by Kilo » Sat Dec 02, 2017 9:53 pm

I use a 4,433 MHz Crystal because of PAL standard.
Well... I sold my scope month ago, so I only can feel the Signal with my tongue! :lol:
Don't know. Normally the TV should recognize anything when I power on the board.
But with the uzebox nothing happened. I built this circuit already once with success but there I used Hsync and Vsync seperated.
Don't know if this is the reason?!
The last digit of Pi is 7! I calculated this, as I counted to infinity yesterday!

CunningFellow
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Re: Creating custom Uzebox

Post by CunningFellow » Sun Dec 03, 2017 7:57 am

It will be very hard to say what could be wrong without a scope to look at things.

The MC1377 should work fine for the TV Out. For PAL 4.43Mhz you probably need an acoustic delay line or the colour would be wrong.

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Jubatian
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Re: Creating custom Uzebox

Post by Jubatian » Sun Dec 03, 2017 9:16 am

Kilo wrote:
Sat Dec 02, 2017 9:53 pm
I use a 4,433 MHz Crystal because of PAL standard.
Well... I sold my scope month ago, so I only can feel the Signal with my tongue! :lol:
Don't know. Normally the TV should recognize anything when I power on the board.
But with the uzebox nothing happened. I built this circuit already once with success but there I used Hsync and Vsync seperated.
Don't know if this is the reason?!
How sure are you that this should be working? The Uzebox generates NTSC timing, I assume you didn't attempt to change the Uzebox's frequency (you are using the same 28.636363MHz crystal for clocking the AVR like any normal Uzebox should). The PAL and NTSC vsync generation is slightly different (PAL, NTSC), however there are hybrids (PAL-M in Brazil, what you are doing is rather PAL-60, you can find it on the same Wiki article).

You may also try using the new V.5 bootloader which generates accurate 262p signal (the old bootloaders have inconsistencies in timing which could be a source of problem if your system is very picky).

I took a look at the MC1377 datasheet, on page 8 for the Sync input it says that for PAL a "correctly serrated vertical sync" is necessary. What this exactly means I don't know, but NTSC has 6 serration pulses and PAL has 5, which could be a problem here.

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Kilo
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Re: Creating custom Uzebox

Post by Kilo » Sun Dec 03, 2017 10:05 am

Good point.
That could be the problem. Maybe I have to take a crystal for NTSC and change the circuit to it.
I didn't think about that.
The last digit of Pi is 7! I calculated this, as I counted to infinity yesterday!

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