GBS 8200/8220 CFW Project

[shingouki2]

shingouki2:
Please watch your terminology if you're not entirely sure what's going on. Other people will read your comment, see the words "killed video out" and that's how rumors start.
What actually happens in quite expected:
Enabling the onboard MCU programming mode disables its operation. That's why we do it, to stop it interfering.
But without configuration from the Arduino or similar, there won't be any output. The Arduino has to work.

For the pink video, I don't think it happened from having the Arduino A0 connected to the GBS R line.
A0 is always either an input (to the ADC) or high-z, in case the Arduino is resetting.

I get white/green sparkles now. It won't even reset.

Does it work if you remove the Arduino and the programming jumper? (Ie: Revert the board to stock.)
You will have to experiment with your sync stripper or some different consoles, as the default software is utterly incapable of syncing to video signals.

Sorry I meant it in a playful "I did something wrong" way. I edited my post.

I think the IC is damaged. The GPU on my PS4 was doing the same thing before I sent it back for a replacement (Lucky I bought the extended warranty).

My Arduino was on, so the GBS should have been outputting something. I disconnected it and noticed the discoloring when I turned it on, stock. It looked similar to mixing Pb and Pr components. it's why I was suspecting something happened when plugging into the R line. There was probably some voltage problem or something causing the damage on my end. The image also fades to black almost after a minute or so. Now that I need a new GBS I have options to look into. That HDMI one worth the extra money?

P.S. I was using RGBS from my CPS3 board, so there shouldn't be any sync issues.

[rama]

Someone on the German forum had similar stripes and fixed it by powering his NodeMCU from the GBS 3.3V supply.

@AndehX:
You power your 1881 from the 5V input, right? Power at that spot is contaminated from the GBS bucket converter switching.
It'll work much better if you add a series resistor of 10 to 30 Ohm.
Why not keep using the other LM1881 solution you had?

[rama]

That HDMI one worth the extra money?
...
P.S. I was using RGBS from my CPS3 board, so there shouldn't be any sync issues.

The HDMI one just works for now. The quality will depend a lot on what your display does with the signal.
It works okay on my test tv, but within a pretty big border.

I never had an arcade board and don't know what the GBS does with typical arcade board video levels.
The RGB is probably much stronger, and the sync signals as well. If anything exceeds 3.3V, it can easily damage the chip.
The ADC for sampling incoming RGB has offsets and gains for 0.7Vpp / standard home AV sources.

[AndehX]

You power your 1881 from the 5V input, right? Power at that spot is contaminated from the GBS bucket converter switching.
It'll work much better if you add a series resistor of 10 to 30 Ohm.

Noted, thanks!

Why not keep using the other LM1881 solution you had?

Well, I guess I could. I just wanted to see if using my own circuit on the GBS board might fix the issues I had. So far it seems to be working to my surprise.
Also, if I use an LM1881 circuit on the GBS board, then I can disable it on my gscartsw, then the image on my CRT isn't shifted to the left.

Any ideas about the interference shown in my video? It's not a big deal since it goes away after a while, would be nice to eliminate it though.

[rama]

Yeah, the interference could be from the bad power to the LM1881

[AndehX]

Well I've added a 27 ohm resistor to the 5v input, shouldn't that help? Also, why does it go away after a while? Sounds like whatever is causing it, needs time to warm up before it works properly lol

[rama]

Yep, 27 Ohms will block most of the noise.

At this point, I'd have to debug your setup with the scope. There's some kind of problem, affected by temperature.
It could be anything really. What's up with that huge capacitor can? :p

Also, you've replaced the AMS1117 regulation capacitor, right? It looks like it but it's hard to see.
That part is kind of critical. I've tried several types and sizes there and it looks like the AMS1117 easily goes into oscillation.
Once it oscillates, the picture suffers.
I would put a regular electrolytic there, about 47uF. No low ESR or anything fancy.

[AndehX]

Yep, 27 Ohms will block most of the noise.

At this point, I'd have to debug your setup with the scope. There's some kind of problem, affected by temperature.
It could be anything really. What's up with that huge capacitor can? :p

Also, you've replaced the AMS1117 regulation capacitor, right? It looks like it but it's hard to see.
That part is kind of critical. I've tried several types and sizes there and it looks like the AMS1117 easily goes into oscillation.
Once it oscillates, the picture suffers.
I would put a regular electrolytic there, about 47uF. No low ESR or anything fancy.

Yeah that big can was something I did on my old board last time I had one. Most likely pointless. I've put a smaller one back on.

I replaced the AMS1117 regulation cap with a 22uf tantalum bead as per Ian Stedman's experiments here: https://ianstedman.wordpress.com/gbs-82xx-experiments/
I can put a regular 47uf there if you think it is better suited?

[rama]

Best leave the Tantalum, if you've already got it on there.
It seems the requirement is > ~10uF and not too much nor too little ESR.

For the LM1881, unfortunately I can't really tell if that GBS "SoG input" is an analog input, or a digital one.
The maximum levels for analog are far lower than for digitial.
If I knew for sure that it's digital, it could be driven by up to 3.3V sync. This would allow a smaller (almost no) attenuation resistor, which would then be better for the signal flanks > better PLL stability.

[AndehX]

For the LM1881, unfortunately I can't really tell if that GBS "SoG input" is an analog input, or a digital one.
The maximum levels for analog are far lower than for digitial.
If I knew for sure that it's digital, it could be driven by up to 3.3V sync. This would allow a smaller (almost no) attenuation resistor, which would then be better for the signal flanks > better PLL stability.

I'm assuming you can't just try it and see what happens?

Also, just tried the GBS at stock, without the arduino connected and theres no interference at all. So not sure what to make of that.

What's the A0 pin for? I didn't have it connected to red on the VGA output. Is it necessary?

[rama]

I can't try it and come to a valid conclusion. If the level is wrong, the GBS will fail after a while. No one knows how long that'll be.

A0 is for the auto gain feature. I might remove it though, as it's not working correctly.

[AndehX]

Ran into a small sync issue with the Mega Drive

https://www.dropbox.com/s/dfr44mvocugwq ... 9.mp4?dl=0

Left screen is my BVM, Middle screen is my PEXHDCAP capture card, and right screen in the GBS 8200

[rama]

This is how it looks these days when you loose sync. I'm still working on it and might go back to "no retiming" sync, as it's more stable (but seems less correct atm, I dunno).

People with severe glitches, check you boards! Someone on the other forum noticed this:
(Check the diode below the addon board!)

[AndehX]

it's not soldered properly?

[rama]

Warning!

Please do not use an ESP32 based controller for the moment.
There are some serious power draw issues that need resolving first!

It looks like the ESP32 can put a lot of current onto the common ground, causing all kinds of issues.
People with artefacts and green'ish glitches: It's the ESP32 itself!


ESP8266 and Arduinos are fine.
If you want to check out the new web server, use an ESP8266 board

[AndehX]

aw man, I hope that gets sorted soon. I have an ESP32 on order from Aliexpress

[rama]

I have a lot of options to try.
It's just that the default configuration with ESP32 Arduino is pretty power hungry in bursts.
The fix might be just code, might be a little bit of extra hardware.

I think it's pretty weird that the board causes issues even with all the signal cables disconnected.
The board is powered from its own regulator via the common 5V input to GBS and ESP32.
Still it can cause the GBS to loose sync or produce artefacts.. It's strange.

[rama]

Well, the ESP32 SDK (and thus Arduino) aren't quite finished yet. I'm missing most power saving options.

I restructured the init code, made the I2C more robust against error conditions and did what I could with power saving.
This is now somewhat usable, though I still get occasional glitches if I power the ESP32 board from anything else than the PC USB port.

Power consumption should be much better when the ESP32 WiFi is in client mode.
So once that's coded, things should work well enough.

[AndehX]

Got my ESP8266 today, set it all up, installed the latest gbs control, and now im getting flashing green lines as well as the interference I had before. Tried powering it via the GBS's 3.3v and from the external 5v input. Same result on both

https://www.dropbox.com/s/gilod49ke6lnt ... 5.mp4?dl=0



Update: Tried with ESP8266, ESP32 and Arduino Uno, and they all show the same symptoms. Default firmware shows none of these issues.

[culexus]

Hi I got this up and running but have one question, I did have some problems with one of my monitors that did not like the output.
Is there a way to change the output ressolution? I see on the working monitor that it outputs 1280x960 H 49.8Khz and V 49.8Hz.
If I can get 1280x1024 60Hz I think it will work on my other monitor also

I did test this with an Amiga 500 and the picture is so nice, good job rama!

[rama]

Connect a terminal (Serial Monitor) and send 't5t57t6'. This disables the new sync handling.
It has to be sent each time a preset is loaded.

Check if that fixes it.

Otherwise, go back to an older version on the Arduino, see if you can find where this problem started.

[AndehX]

Connect a terminal (Serial Monitor) and send 't5t57t6'. This disables the new sync handling.

Yep, that fixed it! Both the horizontal flickering, and the flashing green crap are both completely gone now.

[rama]

Okay, thanks for letting me know.
I'll change it back soon then.

Edit:
And done. It'd be nice to know what the docs actually meant by the option though.
It says "Bypass PLL HS to 57 core" but it's not a bypass, more like it enables some SP parameters (retiming controls).
Of course, there's no mention of it in the programming guide. I have no idea whether this is supposed to be used, or not.

[AndehX]

Well I have no idea about any of the programming side, so I couldn't help you there. All I know is that it looks perfect now, and before it was completely messed up lol. So something wasn't right before, but I love this project, so all I can do is test and offer feedback

[rama]

Yeah, no worries. I'm just bummed that no good docs for all these features exist.
It makes them turn from flexibility into traps :p

I probably know what your problem with the option is:
It depends much more on the sync processor sampling phase (at S5_19).
When tuning this, I found that across my devices (consoles and GBS boards), a fixed setting was fine.
Somehow you have a setup where it isn't.

[culexus]

Just a test with my Amiga 500, I did have some problems getting any picture on my monitor but after typing "reset" in the serialmonitor I got it working some how ?
The only problem is that the picture is should be shifted to the left:)


https://www.dropbox.com/s/3bcanw23cumm1 ... 1.jpg?dl=0
https://www.dropbox.com/s/ft3kovhn0jn9h ... 2.jpg?dl=0

[rama]

Heh, it started working because your command starts with 'r' (and it probably ignored the rest).
The 'r' command manually loads a PAL 50Hz preset.
It should not require that though, so I assume Amigas generate video timings that fail to get auto detected.

Could you send the 'i' command (for information) when it works, then post 5 lines of the output here?

[AndehX]

I probably know what your problem with the option is:
It depends much more on the sync processor sampling phase (at S5_19).
When tuning this, I found that across my devices (consoles and GBS boards), a fixed setting was fine.
Somehow you have a setup where it isn't.

Well I have it all set up as described in your guide. The only difference I can think of, is that the RGB input to the GBS is coming from the outputs of my BVM. Maybe the BVM changes the sync in some way? I always thought it was just a simple passthrough...

[culexus]

Heh, it started working because your command starts with 'r' (and it probably ignored the rest).
The 'r' command manually loads a PAL 50Hz preset.
It should not require that though, so I assume Amigas generate video timings that fail to get auto detected.

Could you send the 'i' command (for information) when it works, then post 5 lines of the output here?

This is the startup code: (Gives me picture on one of my monitors with 1280x960 50khz) This works as default and it detects the amiga output.

Code: Select all

starting

ing RGBS inputs
PAL timing 
 SOG lvl 10
resetDigital
 clampPositionStart: 1592
 clampPositionStop: 1680
post preset done
starting
resetDigital
using RGBS inputs
PAL timing 
 SOG lvl 10
resetDigital
 clampPositionStart: 1592
 clampPositionStop: 1680
post preset done

MCU: 16000000
in field time: 20030
out field time: 20090
 Start HTotal: 2167
2160: 5
2161: 5
 End HTotal: 2160

My next monitor that I want to use is a newer dell monitor that need minimum 60khz to give a picture.
If i only type "i" the serial monitor spits out continius lines with :

Code: Select all

h:430 v:625 PLL:2 status:0 mode:2 ADC:7F hpw:126 htotal:1701 vtotal:311
h:431 v:625 PLL:2 status:0 mode:2 ADC:7F hpw:126 htotal:1701 vtotal:311

I tested just typing "r" but I then it only gives picture on the monitor that supports 50khz. To get any picture on the 60Khz I need to type "e" then it outputs a 60khz 1280x960
So the thing with typing "reset" was my fault, I do belive it startet with the "r" command and then jumped to the next "e" command that gave me 60khz.

Serial monitor for "e" command:

Code: Select all

ntsc preset
 SOG lvl 10
resetDigital
 clampPositionStart: 1592
 clampPositionStop: 1680
post preset done
in field time: 20030
out field time: 16709
 Start HTotal: 1802
safety triggered lower 1801
 End HTotal: 1802

I also found that if I send "h" command i shifted the picture horizontal when Scale Hor: 525 I get to see the whole picture.

Im not shure on all the things I did but it gives me a nice picture

Is there a command list ? And is it possible to set the commands default on startup?

[rama]

Okay, the other monitor you use can't display 1280x960@50Hz. Maybe it can use a lower resolution though: Try '2' (PAL feedback clock preset).
You want a "PAL" preset for your Amiga, since it generates 50 frames per second. Using 'e' loads the NTSC / 60Hz preset, which won't scroll smoothly.
All will be well when '2' works

The list of available commands isn't documented because I keep changing things all the time.
It will be in the user interface though.
The UI is available if you have an ESP8266 or ESP32 board, using WiFi to display a nice control website.
If you want to use such a board, go for an ESP8266 one. They're mature and work well. (About 5 bucks on Ebay)

Saving user settings is on top of the ToDo list!