Hmm this sounds like it might be trying to downscale via RGBHV, are you using a HDMI to VGA dac into the ODV?
I used hdmi to vga adapter with Switch to connect to ODV. And as for connecting to CRT TV i’ve used UMSA to VGA output of ODV(Ultimate Scart Adapter “VGA to Scart RGB”).
On ‘regular’ custom GBSs you have to sync combine VGA (RGBHV) input to RGBS first if you want to downscale over the VGA port, not sure how it is on the ODV but it might be the same.
So a second UMSA/Sync combiner is needed, basically.
Two UMSA’s… interesting. One to input, second to output?
That’s right. The other option is to transcode HDMI to YPbPr and side step the need for RGBS input.
If you have soldering skills there is this solution: Converting RGBHV to RGBs for the GBS-Control - Cathode Ray Blog He’s using it on the output but should work on the intput too. I’ve seen this method be called a hack so it’s not as good as a solution as the UMSA or the similar device from Tim Worthington.
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I have soldering skills, it’s not a problem for me.
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There’s this PCB I found that does RGBHV to RGBS, looks like the sync out will be TTL which should be fine for the GBS-C as I believe it’s fine with TTL C-Sync: VGA to RGB+Sync Converter - Share Project - PCBWay
It looks to be based on the second schematic here (you’ll have to tap 5v from somewhere on the GBS and thus only use 5v when powering the GBS): VGA to RGB+sync converter
I might try and build a PCB for the first schematic as it’s 75ohm safe sync, means I could use it with hardware not compatible with TTL.
Looks like @Danexmurder and @matt already discussed making this here!:
Did it work okay for you guys?
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Ah this is the thread where that sync combiner circuit image Dane posted is from:
Another sync combiner but this time using pin 9 to power the IC:
iirc not every device puts out power over pin 9 so a bit of a gamble to use that.
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Yeah, I never did get this to work right but I didn’t go after it super hard either. I asked around on some forums and the GitHub but never got much help and lost interest.
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I saw that other sync combiner PCB design on OSHpark mentioned in one of those github threads shame it didn’t work, it looked nice and compact.
Thanks for the update on this!
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Yesterday i’ve soldered VGA to VGA RGBHV to RGBS transcoder based on transistor 2N3904 and it works like a charm with Switch. Now picture is centered well. Thank you very much Vespa for info.
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Awesome! You should take some pictures of your build and document it. Info was always sparse on this and detailed shots would be a huge boon to the community.
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It was already documented. I used this info from Vespa:
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Nice work! Seems it’s working fine, time for some 240p Cannon Dancer!
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Hey, Vespa. I just connected my Wii to a GBS-C AIO from RGBHV to RGBS sync mixer and the picture scrolls on the screen. I don’t know what’s going on?
What’s the second box you’re plugged into? I see GBS-C > Custom Sync Combiner > UMSA?
yep
I think the UMSA is expecting RGBHV and the custom sync combiner is outputting RGBS so it’s not going to work? Should just need a regular VGA cable from the GBS-C to the UMSA in that case.
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Got it
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Forked firmware with multiple real improvements
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