GBS 8200/8220 CFW Project

[Ryoandr]

They are uneven, you need linefilter on for them to look nice

[AndehX]

They are uneven, you need linefilter on for them to look nice

Don't like the line filter, it makes the image look soft, like how a TV with a bad upscaler inside it would scale the image

[rama]

Then it's the Prefer Full Height option.

[AndehX]

Then it's the Prefer Full Height option.

Legend.

[biggestsonicfan]

Hi All,

For those still interested, I've done a quick revision on the PLCC based coupling board: https://oshpark.com/shared_projects/lrvd4065. The jumper on P6 is no longer required as it is directly grounded on the coupling board; normal board function is restored by simply lifting the PLCC+ESP8266 off the board. All thoughts and comments welcome

I know this is a very old post, but I just ordered this board from OSH in hopes to use CFW with my GBS 8220. However, I noticed something that conflicts with the datasheet:



To the top right is the PLCC44 MTV230M IC, which the GBS 82XX uses. On the bottom right is a PLCC44 socket footprint.

Keep in mind, the socket is to fit on top of the chip. So all 3 images are shown from a top-down view.

We can see that 3.3v and GND are on pins 18 and 20 respectively, and that matches the footprint.

However, pins 26 and 27 according to custom PCB are SDA and SCL, but on the chip itself, pins 24 and 23 are SDA and SCL.

The github wiki also states the Debug pin on the chip is pin 30, whereas the PCB is connected to pin 34?

Can someone verify I am interpreting this correctly, or will the PCB as is with a PLCC socket work as intended?

[biggestsonicfan]

Having analyzed the board created by by jmuzi lazst year, it seems that in their haste to create their board, it was mostly incorrectly wired. In fact looking at the board you can see the two GND pins are not connected. I've created a new board based on the one he made with the correct connections. I'll have 2 extra after the order comes in if anyone wants them.

[rememberizer]

This CFW is brilliant work, I've been able to capture arcade games properly since I set up the whole thing!

Is there a way to scale a Raspberry Pi's super wide resolution output though? I'm trying to capture emulation (for games I don't have yet) while playing on my arcade cab. I have mine running on my cab through Lakka, and feeding RGBS to the GBS-control gives me "unknown timing" errors.

[Gekkon]

gbs-control compatible with new SG-VC9900 ?
https://www.aliexpress.com/item/1pcs-hi ... 298f22742c

[Gekkon]

Tell me. SG-VC9900 it's the same as GBS 8200/8220 ?

[Ryoandr]

Looks like a shrunk HDMI GBS with no component ports.
HDMI GBS works with GBSC. It outputs limited range HDMI I believe.

[AndehX]

I built one using a HDMI board for a friend earlier this year and it worked fine. So yes, these will work.

Honestly though, I would recommend using a standard GBS8200, with a cheap VGA to HDMI converter since these have the ability to add audio to the HDMI output. There is no way to add audio to those blue HDMI GBS boards.

[Gekkon]

And what is this 4-pin non-soldered connector next to HDMI?

[retromaniak]

Welcome. I modified the board and launched CFW. Unfortunately, I can't handle the soldering iron very much so I had to ask for help. However, this is not about it now. I wanted to ask you if you know any interesting housing designs for this device? I have access to a 3D printer so I thought about getting a nice looking box. Unfortunately, what is available on thingiverse is usually created with original PCB in mind (without GBS-Control). Unfortunately, I don't know much about 3D modeling programs. Hence the question for you about such a project. Personally, CFW I bet on Wemos D1 mini (chinese clone this microcontroller).

[AndehX]

Welcome. I modified the board and launched CFW. Unfortunately, I can't handle the soldering iron very much so I had to ask for help. However, this is not about it now. I wanted to ask you if you know any interesting housing designs for this device? I have access to a 3D printer so I thought about getting a nice looking box. Unfortunately, what is available on thingiverse is usually created with original PCB in mind (without GBS-Control). Unfortunately, I don't know much about 3D modeling programs. Hence the question for you about such a project. Personally, CFW I bet on Wemos D1 mini (chinese clone this microcontroller).

https://www.thingiverse.com/thing:3913273

You're not looking hard enough

Actually, rama, I was curious, is it possible to tap the RGBHV signal from those blue HDMI boards? Say if you needed VGA out instead of HDMI for whatever reason?

[rama]

biggestsonicfan:
You could just wire up your first board to the pin headers normally, then go from there.
The small page on the adapter I made is a good start, if you want to do a PCB.
https://github.com/ramapcsx2/gbs-contro ... rd-Adapter

Gekkon:
It's the first time I hear about an "SG-VC9900", but yes, this is the HDMI version of the GBS8200.
It's compatible with gbscontrol, but it obviously lacks Component Video input support.
I agree with AndehX. It's better to get a regular GBS8200 and the HDMI dongle.
The 4 pin header you found is what you probably think it is: The control port for the HDMI chip.
I've asked the company for their HDMI chip register descriptions. Sadly, I didn't manage to get them.

rememberizer:
The problem sounds like the mode detect unit doesn't recognize what the RPI sends.
I'm working on doing a little more with "unknown signal" situations, so maybe a future update improves the situation

retromaniak:
The 3D design by sanni that AndehX linked to is great
https://www.thingiverse.com/thing:3913273

[rama]

Actually, rama, I was curious, is it possible to tap the RGBHV signal from those blue HDMI boards? Say if you needed VGA out instead of HDMI for whatever reason?

It's certainly doable, but the mechanical side of adding a new VGA connector is troublesome, and the RGB is already double terminated for the HDMI chip.
If you added a VGA connection, this double termination would have to be bypassed for VGA, and in place for HDMI. Tricky :p

[AndehX]

Actually, rama, I was curious, is it possible to tap the RGBHV signal from those blue HDMI boards? Say if you needed VGA out instead of HDMI for whatever reason?

It's certainly doable, but the mechanical side of adding a new VGA connector is troublesome, and the RGB is already double terminated for the HDMI chip.
If you added a VGA connection, this double termination would have to be bypassed for VGA, and in place for HDMI. Tricky :p

Ok, just checking because my friend has one for his streaming setup, but he's just been given a CRT PC monitor, and wants to play his retro games on it. Can't do that with HDMI

Also, on the standard GBS boards, do both VGA outputs work at the same time? so you could output to 2 monitors?

[rama]

I don't think the DAC can drive 2 outputs simultaneously.
Get the dual output GBS board for that. It has a display driver chip that can do 2 displays.

[retromaniak]

Hi. The question may be a bit silly but I wonder what VGA to HDMI converter do you recommend? I found such a thing but I wonder if it can manage this device sensibly display HDMI image? If you know a bit more expensive device but you think it is better, I will also be interested in it.

https://s.click.aliexpress.com/e/7v3zNudKF

[AndehX]

Hi. The question may be a bit silly but I wonder what VGA to HDMI converter do you recommend? I found such a thing but I wonder if it can manage this device sensibly display HDMI image? If you know a bit more expensive device but you think it is better, I will also be interested in it.

https://s.click.aliexpress.com/e/7v3zNudKF

These are the 3 I have tried, and they all provide the same result. They all work fine.

https://www.aliexpress.com/item/33049881446.html
https://www.aliexpress.com/item/32880559763.html
https://www.aliexpress.com/item/32692452101.html

[retromaniak]

These are the 3 I have tried, and they all provide the same result. They all work fine.

https://www.aliexpress.com/item/33049881446.html
https://www.aliexpress.com/item/32880559763.html
https://www.aliexpress.com/item/32692452101.html

what is the sound quality of this converter?
https://www.aliexpress.com/item/33049881446.html

[rama]

Audio quality?

These adapters include an ADC to digitize audio for HDMI.
There isn't much that can go wrong there, so assume that the audio is just fine.

By the way, I recommend you get the dongles for the shortest transmission line possible.
https://www.aliexpress.com/item/32880559763.html

[AndehX]

While the dongle is most likely the best option for the reason rama stated, I should note that out of the 3 I tried, one of them wouldn't display 720p for whatever reason. I'd say the build quality is the worst out of the 3 on them too.

[biggestsonicfan]

biggestsonicfan:
You could just wire up your first board to the pin headers normally, then go from there.
The small page on the adapter I made is a good start, if you want to do a PCB.
https://github.com/ramapcsx2/gbs-contro ... rd-Adapter

Sadly, something I had not considered in my redesign was that the spec sheet was, in fact, incorrectly documented. RIP. I had 6 boards made, 2 sets of 3 with one fat and one skinny.

I am making a 3rd revision, which is basically a clone of jmuzi's, but using traces on both the top and bottom of the PCB. Also, their version did not connect GND to GND, mine will. And because I know this version will be correct (I am using a 44-pin test clip and have verified everything works) I am thinking of a logo to put on it or something to make it pretty and appealing.

[rama]

So, err, is my wiki page correct with the pinouts? :p

One other important thing for your pcb project:
WiFi susceptibility to noise is a serious problem with the ESP8266 (or any other module that uses small PCB antennae).
Placing the ESP8266 at a location close to the main EMI radiator (heatsink of the scaler chip) means there's going to be issues at some frequencies.
I've done everything I could in software to try and work with the problem, but if the WiFi radio is broadly swamped, there's just no way to fix this in software.

A pcb could be used to dampen the EMI, but a lot of experimentation would be required.
A ground plane that extends over the antenna area could be beneficial.

[Iraito]

While playing with my ps2 and component cables i noticed a weird behavior, if i play games from discs everything looks perfect but when i use open ps2 loader the menu of OPL is shaky and so are the games, even the same ones that i play issues free from discs.

[retromaniak]

Welcome. I have a question. Namely, I ordered a VGA -> HDMI converter. However, I would like to connect it directly to the board so as not to block the possibility of connecting a VGA monitor to the board. For this purpose I would like to use the connector derived from VGA. As I have GBS-8200, this connector is located next to the VGA. However, I am interested in some information related to this derivation. I would like to know if this connector is connected to the mass of the device? The second question is what type of connector is it exactly? From what I was able to find, it is most likely the JST connector. I am not sure, however, is it really a connector and it is half the battle because the question remains what type of JST connector is?

I would simply like to remove the converter (VGA -> HDMI) from the original housing and desolder the VGA and then attach the connector in this place.

[rama]

Iraito:
I always need as much information as you can gather when you report a problem.
You describe "shaking", but what am I going to do with that?
Please try and get some logs, maybe a short video, anything that shows what's going on.

retromaniak:
Whatever the other connector is, you can only use one display device with a GBS8200.
(HDMI adapters also count as one "display" device.)
If you tried to connect 2 devices anyway, the display will be too dark, and the scaler chip might be damaged.

If you want to use 2 outputs, you need the GBS8220.

[retromaniak]

retromaniak:
Whatever the other connector is, you can only use one display device with a GBS8200.
(HDMI adapters also count as one "display" device.)
If you tried to connect 2 devices anyway, the display will be too dark, and the scaler chip might be damaged.

If you want to use 2 outputs, you need the GBS8220.

I understand. Actually, for this design I was inspired by the design of this housing:
https://www.thingiverse.com/thing:3913273

There, the WII2HDMI was connected to the JST connector. So it filled me with hope that it would be possible to simultaneously display the signal fed to VGA and to output JST. However, if you say that this is impossible then I will use the B plan and plug VGA splitter like this http://tiny.cc/k425gz. I wonder, however, if the situation with too dark image would not improve connection to pin number 9 on the 5V signal vga connector. I was inspired by this list of exits. https://pinouts.ru/Video/VGA15_pinout.shtml Maybe the 5V signal would allow GBS 8200 to support 2 VGA outputs. If not, then plan B will remain

[NoAffinity]

This connector works with gbs 12 pin output next to the hd15 connector.

https://s.click.aliexpress.com/e/dCF7VMHK

Order the 12 pin jst connector of course.



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