Decoding the Gameboy LCD output.

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RogerClark
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Re: Decoding the Gameboy LCD output.

Post by RogerClark » Tue Nov 14, 2017 7:49 pm

ZeroWalker wrote:
Tue Nov 14, 2017 7:42 pm
Oh, that's scary :(
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stevestrong
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Re: Decoding the Gameboy LCD output.

Post by stevestrong » Tue Nov 14, 2017 7:49 pm

I meant the scope plots showing the LCD control signals, these:

Image

Image

The are showing different Vsync shapes.

ZeroWalker
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Re: Decoding the Gameboy LCD output.

Post by ZeroWalker » Tue Nov 14, 2017 7:55 pm

Ah, no it's not, it's just really zoomed in.
2017-11-14_20-55-11.png
2017-11-14_20-55-11.png (44.93 KiB) Viewed 75 times

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Pito
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Re: Decoding the Gameboy LCD output.

Post by Pito » Tue Nov 14, 2017 7:56 pm

more and more of the internet is getting blocked for me
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stevestrong
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Re: Decoding the Gameboy LCD output.

Post by stevestrong » Wed Nov 15, 2017 9:19 am

More and more I think that you have to go back to scan parallel the input port (both bits 0 and 1) controlled by DMA triggered by capture input on CLK falling edge. This because the clocks are really weird and unpredictable, the free time to process on main level is not reliable.

Otoh, an F4 would maybe better suited, is much faster as it runs with 168MHz and it has the ART accelerator.
Has also USART supporting 10Mbps.
Yes, it is ~10USD (the mini F407VET6), but each cent is good invested value.

ZeroWalker
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Re: Decoding the Gameboy LCD output.

Post by ZeroWalker » Wed Nov 15, 2017 9:57 pm

Well in that case i might as well use one of my OrangePi i guess, will have to give it a go at some point and see if they are capable of it.

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RogerClark
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Re: Decoding the Gameboy LCD output.

Post by RogerClark » Wed Nov 15, 2017 10:58 pm

ZeroWalker wrote:
Wed Nov 15, 2017 9:57 pm
Well in that case i might as well use one of my OrangePi i guess, will have to give it a go at some point and see if they are capable of it.
What OS are you running on the OrangePi ?? Most OSs that run on these sorts of boards are some sort of linux, and have high latency.

You could potentially write your own driver, but it seems like a lot of work...

Or is there some sort of truely real time OS for the OPi?

Edit ..

http://www.orangepi.org/orangepibbsen/f ... d&tid=1934

ZeroWalker
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Re: Decoding the Gameboy LCD output.

Post by ZeroWalker » Thu Nov 16, 2017 11:49 am

Not well read on it, but have read that thread you posted a bit.
Also know of something called FreeRTOS, that might also be something, and ChibiOS (i think).

Though it might all be just a super pain, i am just a mediocre programmer, so too advanced stuff is, well too advanced xd

stevestrong
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Re: Decoding the Gameboy LCD output.

Post by stevestrong » Thu Nov 16, 2017 12:02 pm

I still think it is doable with the blue pill, if the OV7670 parallel data scan works with 8MHz clock, this should also work with the half 4MHz clock.
https://github.com/stevstrong/LiveOV767 ... 0stm32.ino

ZeroWalker
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Re: Decoding the Gameboy LCD output.

Post by ZeroWalker » Thu Nov 16, 2017 12:57 pm

Hmm that's true, the problem still lies in transferring the data doesn't it?
Cause even if stm32 gets it all right, the data is kinda useless if it's just lying there;P

The usb stuff was a bit too much for me to get my head around sadly.
Though there are other options, it's too bad that the USB breaks on overclock, else that could possibly have been a solution.

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