GBS 8200/8220 CFW Project

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dwards
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Re: GBS 8200/8220 CFW Project

Post by dwards »

Hi AndehX,

This socket mod looks fantastic! Does the socket supply connections for power, ground, all I2C, Debug and VSync? So no other connections are required besides the socket pins?

I think I'll give this a try, what pins on the PLCC need connected to what? Also do you think a good rubber band would hold this down LOL?

Thank you,
dwards
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AndehX
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Re: GBS 8200/8220 CFW Project

Post by AndehX »

You can get all the required signals from the chip. Heres the pinout (taken from circuit-board.de)

Image
Higgy
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Re: GBS 8200/8220 CFW Project

Post by Higgy »

Just updated to latest code and I got my Chinese scanline generator through the post. Seems pretty good for just over £10.

https://www.ebay.co.uk/itm/Scanline-Gen ... 2749.l2649
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AndehX
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Re: GBS 8200/8220 CFW Project

Post by AndehX »

I got the exact same one, and yeah, it looks great!
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

Hey, is anyone running the current firmware?
I need a few opinions on the active frame time lock and on the software scanlines.
Both are toggle options in the web ui.

Cheers :)
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AndehX
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Re: GBS 8200/8220 CFW Project

Post by AndehX »

Just updated to the latest firmware. Did some testing with the scanlines.

Scanlines via gbscontrol:
Image

Scanlines via Scanline Generator:
Image

From what I can see, the scanlines in gbscontrol look more uniform, but are pretty faint on certain colors like reds/dark blues/greens and other dark colours. They look crisp and vibrant on whites/yellows etc. I'd say you're definitely on the right track, they just needs some adjustment for the darker colors.

Oh here's a full pic for prosperity :P
Image
chkktri
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Re: GBS 8200/8220 CFW Project

Post by chkktri »

rama wrote:Hey, is anyone running the current firmware?
I need a few opinions on the active frame time lock and on the software scanlines.
Both are toggle options in the web ui.

Cheers :)
I've been fiddling with it for a while. Finally, on later commits NTSC feedback lock preset gives pixel-perfect image (still somewhat blurry compared to PAL preset, though) however progressive modes don't work with low-res presets, I get only 1/4 of screen for some reason.

Active frame lock seems to work, however image shifts up and down every update.

Scanline mode works nicely so far, need to adjust vertical focus on modern CRT though, otherwise lines are too thin.

P.S. Is there a way to interpret 240p image which is sent as 480i as progressive? PS2 games like Mushihime-sama, Metal slug anthology and older Taiko no Tatsujin games seem to output image this way making it shaky.

P.P.S. I use Arduino Uno and an European PS2 for all this.

Image
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

The scanlines themselves can't be modified but the overall image should probably be tuned with them on.
Otherwise they're too dark, imo.

Please keep testing new versions. The active frame time lock is still being worked on.
I get the up/down shifting as well, but only in presets other than NTSC normal. This can be fixed, too.

chkktri:
There might be a way to fix the bad 480i image but nothing comes to mind right now.
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

Update:
The bobbing should be fixed now.
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Syntax
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Re: GBS 8200/8220 CFW Project

Post by Syntax »

I'm an absolute noob when it comes to programming these things so for all the other noobs out there.

Buy a ESP8266 WeMos D1 mini

pin outs
D1 = SCL
D2 = SDA
G = Ground
5v= +5v
D7 = VSync
D6 = Debug

Follow the hardware wiki
https://github.com/ramapcsx2/gbs-contro ... e-Hardware

Download Arduino
Go to preferences/settings and add this url to the Additional Boards manager URLs
http://arduino.esp8266.com/stable/packa ... index.json

Go to tools/board/boards manager and scroll to the bottom and install the ESP board library

Choose your board

Download these as a .zip and add them to libaries via sketch/include library/ Add .Zip library
https://github.com/tzapu/WiFiManager
https://github.com/ramapcsx2/gbs-control

File/open gbs-control.ino (its in your documents in an Arduino folder in a gbs folder....)

Follow the prompts and then Sketch/upload.

After upload is complete unplug the board from power and plug it back in. Be sure that both the gbs and ESP are connected to each other and powered.
Scan for your new wifi point which should be called

gbscontrol
Password: qqqqqqqq

open a web browser and type http://192.168.4.1/

enter your wifi settings for the GBS to connect

Now let the ESP reset and connect to your network, it may take a minute or 2 to show up.

Connect to it via its ip address, mine was http://192.168.1.68/

http://gbscontrol does not work for me at the moment for some reason.

Hope it helps save someone some time.
Last edited by Syntax on Tue Apr 17, 2018 12:20 am, edited 4 times in total.
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AndehX
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Re: GBS 8200/8220 CFW Project

Post by AndehX »

yeah the WeMos D1 doesn't seem to work with http://gbscontrol for some reason. I just use the IP address
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Syntax
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Re: GBS 8200/8220 CFW Project

Post by Syntax »

So since day 1 I've had terrible moiré lines when using my GBS. I was hoping that the custom firmware mods would help this, and it did somewhat but I still had really bad interference on the screen.

Looking at the wiki I notice one model had a crappy capacitor trying to dampen the LDO oscillation so I checked my boards capacitor there. C11

Turns out its a 100n (measured 114) but I replaced it with a new 100n (measured 95) and it seemed to help the interference a whisker but it was still evident that the LDO was oscillating. If I put my finger on C11 the inference got worse.

These LDOs should have a ceramic cap around 100n and a tantalum(better ESR) or electro capacitor around 220uf on the output but my board doesn't even have a spot for one, just that 100n ceramic.

So I fit a 220uf tantalum capacitor directly between the LDO ground and output and guess what? I now have a crystal clear image. :D

Feel free to add this to the wiki.

Image
Image
Last edited by Syntax on Mon Apr 16, 2018 3:15 pm, edited 1 time in total.
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AndehX
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Re: GBS 8200/8220 CFW Project

Post by AndehX »

You can also desolder C11 and replace it with the tantalum. I did that to mine and the result is the same as yours
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Syntax
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Re: GBS 8200/8220 CFW Project

Post by Syntax »

Off the top of my head the pdf for that LDO requires a ceramic and tantlum on the output, but I'm sure just the tantlum works fine.

Skimming through the thread i must of missed where people were adding caps to the LDO to fix interference, I thought most of it was blamed on sync strippers, my bad.
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

@Syntax:
Hm, you found another board revision with an oscillating LDO then.
Yeah, the fix is to either remove C11 and leave it like that, or replace C11 with any electrolytic >= 22uF.
It's really not critical except for one point: This must not be a low value, low ESR capacitor!
And yep, that's what these boards use: Low value, super low ESR (ceramic cap).

Just removing the cap works, because after a bit of trace on the pcb, there is another electrolytic + ceramics.
This type of LDO requires capacitance on the output, but it must be above a certain minimum ESR.

A tip for your install: The ESP8266 really requires its own capacitor. Add ~100 to ~220uF on your dev board.
Last edited by rama on Mon Apr 16, 2018 6:30 pm, edited 1 time in total.
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

Download Arduino
Go to preferences/settings and add this url to the Additional Boards manager URLs
https://github.com/ramapcsx2/gbs-control
You want to add this URL:
http://arduino.esp8266.com/stable/packa ... index.json
Download these as a .zip and add them to libaries via sketch/include library/ Add .Zip library
https://github.com/tzapu/WiFiManager
https://github.com/ramapcsx2/gbs-control
WiFiManager is available via the Arduino IDE Library Manager, no need to download the zip.
Gbs-control can be downloaded as a zip and put anywhere. More advanced users may want to git clone instead for easy updates.
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Syntax
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Re: GBS 8200/8220 CFW Project

Post by Syntax »

Looks like it was a bit late when I typed that up and doubled up on the wrong url. Edited.

Concerning wifi, the latest build of Arduino is what I used and it prompted me to install the WiFi library before compiling my first time.

Found out that the sync regeneration supplied from a Gscart lite switch is not compatible with gbs.

If you regenerate what is already csync it works fine but wont work with regenerated sync built from composite video.

Real shame as I was hoping to avoid a different stripper.

I'll just fit one to the gbs I think.
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

Are there schematics for the Gscart lite switch?
The problem surely is wrong signal levels.

Edit:
Found a description of the device, but no schematics yet.
The GBS definitely won't work with RGBHV right now. Gbs-control doesn't handle a separate vsync signal (yet).

It will work nicely with any form of csync, as long as the levels are correct.
Your switch probably requires a 75Ohm termination, so make sure you install the 100Ohm resistor between sync-in and ground on the GBS.
(100Ohm because there's additional termination already installed, it's just a wrong value.)
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Syntax
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Re: GBS 8200/8220 CFW Project

Post by Syntax »

I'm not sending rgbhv from the gscart, there's not really a way to do that. Just all my 240p consoles with composite video for sync. Was hoping to just flick the switch and have it work.
I'll add a resistor and check but it should be putting out a perfect csync signal.

Fyi the gscart digitizes the sync signal to clean it then puts it through a dac it doesn't use a LM stripper.
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

To be more clear:
Every GBS board requires the 100 Ohm to ground resistor on sync-in. It's in my documentation :)
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Syntax
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Re: GBS 8200/8220 CFW Project

Post by Syntax »

rama wrote: It's in my documentation :)
Where? I just looked over the wiki and and saw no mention of this.

Couldn't find a 100R around the house but i had some 82R so I removed the 1k @ R34 and put an 82R across ground and sync pins of the RGB header.
Ends up with 75R
Higgy
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Re: GBS 8200/8220 CFW Project

Post by Higgy »

It's there, you want to build the Sync Stripper with the black background. It has the resistor to GND on Sync In.
As per here:

viewtopic.php?f=6&t=55948&p=1153713#p1153713

I converted my other Sync Stripper to this circuit. I use it to connect all my old computers/consoles to a Commodore 1084 monitor.
On a sight side note, I got a 1084S-P the other day with 8 & 6 PIN DINS analogue & TTL RGB). Finally I got it working to accept RGB systems :)
It needs from the LM1881 = CSync + VSync. My 1084S-D just needs CSync for analogue RGB.

Syntax -looks neat soldering the Mini directly to the chip. I might do that. I was thinking of putting my Mini on some breadboard and using a post on one of the corner holes to mount it.
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

Here it is! :D

Image

Seriously though, you want to create a sync in situation the same as a regular TV.
Then every "TV compatible" source should work with your scaler.
The GBS comes with 1kOhm sync-in termination. To normalize it to act like a TV, add an additional ~75 to 150 Ohm to ground (ideally 100 Ohm).

I guess I should add that to my written notes.
Edit: Done.
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Syntax
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Re: GBS 8200/8220 CFW Project

Post by Syntax »

Oh man how did I ever miss that :D

My GBS has 2 1k resistors to ground but i couldnt find the 2nd one so 82 was pretty much perfect for me.
It didn't fix the GScart sync cleaning issue I'm having unfortunately. I may try a pot inline on sync to see if that's the problem because its almost playable at times.
For now I'm just feeding the GBS csync from my consoles.
Accidently plugged in a sync on luma cable for my PS1 and the GBS synced fine, which was a nice surprise.



@Higgy - Placing the Wemos there seemed like a good idea, there is pretty much only ground plane on the GBS board in that spot so no interference.

I also glued a scart plug on the bottom but thats been hidden from my pics.
Image

Absolutly stoked with how everything is working for me, The GBS is now my go to for PC Crt gaming.

Thanks Rama, and everyone else involved in getting the project to this point.

Now time to compare to the OSSC... :mrgreen:
Image
Ryoandr
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Re: GBS 8200/8220 CFW Project

Post by Ryoandr »

Hello all, I received my 8200 board, waiting for the 8266 so I can really start.
Is there anything spacial I should know about the 8200 in vanilla form ? Cause so far it has awful compat...

SFC worked fine, but switched PAL MD had a lot of issues :
50hz worked fine
60hz had flicker or frozen screen.
I know that a 60hz switched PAL MD has slightly off-specs refresh because the master crystal is different, however I have another switched console with an NTSC crystal, making it effectively equivalent to a JP MD or a Genesis, and I have the same results (fine in 50hz, flicker or frozen screen in 60hz).
Using either C-Sync, or luma as sync. I'm going to try sync through an LM1881, however I'm doubting the results as the SFC worked fine with Luma as Sync...
Higgy
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Re: GBS 8200/8220 CFW Project

Post by Higgy »

Hi.

There is a capacitor which is recommended to be changed, details are on the GBS Control Github page.

A lot of the issues are fixed with this custom firmware. ;)

I would build a LM1881 circuit into a female SCART, then you can pretty much plug anything into it (well if your from UK/Europe and have SCART).

Cheers
Ryoandr
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Re: GBS 8200/8220 CFW Project

Post by Ryoandr »

I have the revision V4.0 20091204, black buttons ; same as on the wiki "rgb potentiometers" page. So no need for cap removal ?
I tried an LM1881 and I did get a stable signal at least.
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Syntax
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Re: GBS 8200/8220 CFW Project

Post by Syntax »

Ok so for some reason gbscontrol works on my phone now.

Also occasionally I cannot connect to gbs while it has video input, the second I remove video input it's back on the network.

I'll add a cap to the wimos and see if it helps or is this that ntsc signal breaking WiFi??
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

I speculate that the H-PLL produces harmonics of the locked frequency and those radiate around the 5725.
This EMI appears to sit spot on on the WiFi 2.4Ghz when using the default NTSC preset, and it drowns the capability of the small dev board antenna.

Fixes I've found so far:
- Change your router's WiFi channel. The effect was only happening on channel 1 here.
- Change the H-PLL divider in the preset. Changing it from 0x855 to 0x859 fixed the issue (command 'n' 4 times on Serial Monitor terminal).

This won't be easy to fix with shielding or the likes, as the problem is essentially a lot of EMI near a small sender / receiver.

Another note on the WiFi hostname: I totally forgot that you have to attach your home networks domain to the hostname.
In my case, it becomes http://gbscontrol.fritz.box
rama
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Re: GBS 8200/8220 CFW Project

Post by rama »

Any WiFi antenna / EMI people here? This is kind of annoying :p

I wonder if there's anything I can do on the software side to improve the situation.
On the hardware side, maybe some kind of shielding is possible.
The EMI probably radiates from the heatsink of the scaler chip.
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