https://circuit-board.de/forum/index.ph ... /?pageNo=2
To the questions!
brightness:
I don't know what kind of cables are being used (what extra components are or aren't installed).
The GBS itself is configured to produce 0.7Vpp (100%) brightness *IF* the source delivers 0.7Vpp as well.
Most consoles I tested do not deliver as much, all depending on the cables.
For that reason, there is an auto adjustment feature that monitors the red output and tries to bring it to 100% over time.
It needs a cable connected from a Red (or Green, or Blue) output pin (use the extra pin header besides the VGA out port) into Arduino A0.
Then in the software, in setup(), set rto->autoGainADC = true;
It measures only one output but adjusts all 3 RGB channels.
The feature isn't very reliable yet but you can try!
A late generation PSX delivers the correct amplitudes by the way. (anything > SCPH-700x)
scanlines:
I like those, so I'll definitely try to get something like an SLG working. At the moment, it's probably just the sync pulse polarity that's off.
People requesting a 640x480 preset with that in mind, please hold out while I look into it. Chances are, it's just a bit to toggle and the usual preset will work.
resolutions in general:
This is a big one. It's very hard for me to create different resolutions. This is due to the amount of video timing knowledge necessary to even begin doing it.
I'm slowly learning though, and I'll need this to develop common TV compatible presets.
Do note that only the current (1280x1024) preset is fully optimized to fix many typical GBS problems.
There's filters to set, the H-PLL to tune, the Memory Controller to tune.. All on top of the video timings challenge.
Everything has to mix nicely to produce a good image.
Scart female to VGA male adapter:
Look what I found: viewtopic.php?f=6&t=35423
It basically has to be an RGB passthrough + a solution for Sync. An LM1881 sync stripper works great with the GBS board.
Remember to attenuate the output with a 670 Ohm series resistor!
Get your 5V from the Scart cable (the console).
Alternatively, the LM1881 could be on the GBS board, fed by the input power supply (if that is 5V), or even by the GBS 3.3V.
In the 3.3V case, we're working with too little voltage. It works in my tests but it's not ideal and some care must be taken with bypass capacitors.
Are tests / reports useful?:
Very! I can only test with the hardware and time that I've got. You guys with your particular setups will discover problems that I'd never encounter here.
Also, it tells me what people want to see the most.
If you have capture hardware, videos would be great!
)
