The ultimate VGA to SCART adapter

[gambaman]

I have published here an enhanced version of my previous VGA to SCART adapter. Unlike the previous version, the new adapter does not require any external power source nor DC-DC converter to generate the 12V of the SCART status signal thanks to Visenri's indications. Also, the transistors employed to generate the RGB selection signal in the previous version are no longer needed. The adapter has the following pros:

• It's cheap thanks to the unexpensive PIC16F18313.
• It automatically detects the polarity of the input VGA sync signals and configures the configurable logic cells (CLC) of the PIC dynamically to generate the SCART composite sync signal correctly.
• The PIC monitors the input signal and set the composite sync to ground if the frequency of the horizontal sync signal is wrong or if the vertical sync signal does not change. This is useful if you are using it to generate the Csync signal of a very old arcade monitor to protect it. Also, if any of the input sync signal is wrong then the PIC disables the the SCART RGB selection signal and the SCART status signal.
• Most VGA devices can provide enough power to the PIC so no external power source is required.
• No external power source nor DC-DC converter is required to generate the 12V of the SCART status signal. It can be generated by the PIC itself as noted by Visenri.
  
• Optional aspect ratio selection (16:9 or 4:3).
• Optional LEDs  to test the power and input sync signals.
• Optional power source selection.
• The basic circuit only requires the PIC and a pair of resistors and capacitors.
• The full circuit fits in a (big) DE-15 enclosure using a single sided PCB and easy to solder through-hole components.

UPDATE: I am happy to say I have found two stores selling implementations of this adapter.

One is https://www.arcadexpress.com/es/arcadevga/457-cable-arcade-vga-scart-usb-5v-12v-con-audio.html
This implementation looks almost identical to the original, except the position of the LEDs.

Another one is http://vga-scart-converter-f-15.mozello.es/catalog/params/category/0/item/1443803/
The appearance of the latter is quite different. The switches are more accessible so that the power supply or the aspect ratio of the screen can be changed without having to open the adapter. Another notable difference is that it has a female VGA input and two SCART outputs, one male and one female. The adapter can be connected directly to the TV with the male SCART connector. Alternatively, it can be connected via the female connector using a SCART cable.




UPDATE: The box version above is not on sale anymore, buy all the design files are available here.

UPDATE: buttersoft has designed a
SOIC version of the adapter that can be directly solded to the back of a DB15HD male solder plug, and should fit inside any backshell, with room to connect a cable too. You can get it here.



UPDATE: MonochromeVGA is a project from Aitor Gómez to enjoy the charm of those monochrome monitors of the time in VGA displays. It makes it possible to select green, amber or B&W as monochromatic color, among others, as well as to change color to monochrome or vice versa easily. You may ask why I'm posting about it here. The reason is that Aitor has combined the MonochromeVGA with my project to get the MonochromeRGB:



MonochromeRGB allows several possible configurations of use:

-VGA to [optionally monochrome] VGA, without the need for any power supply
-SCART to [optionally monochrome] SCART, also without the need for any power supply
-VGA at 15.7Khz horizontal frequency to [optionally monochrome] SCART with selectable 4:3 <-> 16:9 aspect change for compatible TVs, being necessary 5V power supply via microUSB or from the VGA connector itself

I would like to collaborate with Aitor to develop a dual output version for TATE games. Stay tuned.

UPDATE: buttersoft has designed a passthrough dongle. This one is a double-ended version, male HD15 to female HD15. It has the LED's, taking in H-sync and V-sync and allowing C-sync through only when it detects 15kHz, blocking everything else. It allows you to plug in any VGA or VGA-toBNC or -SCART cable to the out end as required. You can get it here.




UPDATE: I am happy to see they are selling another variant here:

[buttersoft]

Good stuff, i love building stuff like this so i'll give it a look.

And the more i look the more i like it. Very neat. And i like that you've included parts sourcing from reasonable places

I notice you've got a cable gland on the end of the DE-15 housing. Do you know where it came from?

[gambaman]

I notice you've got a cable gland on the end of the DE-15 housing. Do you know where it came from?

The SCART-SCART cable I employed for that prototype was very short. So, instead of cutting it into halves, I removed one of the male SCART connectors and used its gland for my DE-15. A better alternative is to cut a longer cable into halves. In that way you can use an only cable to make two adapters (one with each half).

[Mr. Peabody]

Is there supposed to be audio in the video?.....

[gambaman]

Is there supposed to be audio in the video?.....

I removed most of it. Only the corresponding to the sound test (minute 5 more or less) is left. I used to think I had the voice of James Earl Jones till I recorded it .

[gambaman]

Good stuff, i love building stuff like this so i'll give it a look.

I'm sorry if you already got the previous version of the PCB (labeled 1.2). I have realized that the DE-15 was hard to fit because its footprint was wrong  . I have just published a fixed version (labeled 1.4), but I haven't tested it yet.  I have ordered a few PCBs of the new version. I will test them and tell you the results as soon as possible.

[buttersoft]

Hah, no, i didn't order (yet). TBH i have like 6 projects on the go - encoders, SFC mods, CRT repair - and i don't strictly need a scart adapter. I'll get around to it eventually.

[gambaman]

I have uploaded a new version of the PCB (labeled 1.6) with the correct DE-15 footprint and the common ground connections. I have tested it and it works.

[renatopdalencar]

I have no skills with soldering and stuff like that whatsoever. Is there any way to buy this cable (I live in Brazil)?

[gambaman]

I have no skills with soldering and stuff like that whatsoever. Is there any way to buy this cable (I live in Brazil)?

As far as I know, nobody is selling the adapter. You can make a request to a brazilian arcade shop (for example https://www.arcadebr.com.br/). Since the design is "libre", they can make and sell the adapter at will.

P.D: Is the SCART connector usual in Brazil?

[gambaman]

I have no skills with soldering and stuff like that whatsoever. Is there any way to buy this cable (I live in Brazil)?

Somebody is polling to make a batch of adapters: https://www.offidocs.com/loleaflet/dist/loleaflet.html?service=owncloudservice13&file_path=file:///var/www/html/weboffice/mydata/8378688565/NewDocuments/9072788666.xlsx&username=8378688565&ext=yes

[haynor666]

Great stuff

I'm also interested in 2 cables but production will be in Spain. Can add to list even if I live in Poland ?

[gambaman]

Great stuff

I'm also interested in 2 cables but production will be in Spain. Can add to list even if I live in Poland ?

You can ask the guy who is selling the adapter. Just send him an e-mail with the subject "ultimate vga" at rgbux666@gmail.com.

[haynor666]

I'm interested and I've already wrote e-mail to You.

[gambaman]

Great, haynor666. But that e-mail address it not mine. Did he respond you? As long as I know, he is still waiting for components.

[buttersoft]

Hey gambaman, i'm thinking of giving this a go, or at least planning to, but the stencil file for boring the VGA h9ousing is not recognised by any of the fabs i normally use. It needs an outline. Any chance you could update it to have one? Or suggest an alternate method or something?

[gambaman]

Hey gambaman, i'm thinking of giving this a go, or at least planning to, but the stencil file for boring the VGA h9ousing is not recognised by any of the fabs i normally use. It needs an outline. Any chance you could update it to have one? Or suggest an alternate method or something?

It is because of the oval holes, right? I had problems with that. You have several alternatives:
-You can order the PCB at https://jlcpcb.com/. I ordered them there.
-I can change the footprint if you want.
-You can download the KiCad files from https://cdn.hackaday.io/files/1656347086485056/KiCad_ultimateVGA2SCART.zip and change the footprint.
-There is a guy who was selling DIY kits with all the componentes, including PCB and preprogramed PIC. You can e-mail him at rgbux666@gmail.com with the subject "ultimate vga". I don't know if he is still selling them, anyway.

Please, tell me your impressions.

[buttersoft]

I should have been clearer. The main circuit board itself is fine. It's the second dummy PCB to help cut the housing. If you put that into JLCPCB or OSHpark it fails. This is the "ayuda_corte_carcasa-job.gbrjob" file. I cannot dump that directly onto JLCPCB, and if i archive it into a .zip file, it fails to find an outline. I cannot get the raw file to show up in a gerber viewer either, i cannot see it's size and shape at all using that file.

Is there anything i should be doing? I'd love to be able to order the Dummy PCB as well!

[gambaman]

I should have been clearer. The main circuit board itself is fine. It's the second dummy PCB to help cut the housing. If you put that into JLCPCB or OSHpark it fails. This is the "ayuda_corte_carcasa-job.gbrjob" file. I cannot dump that directly onto JLCPCB, and if i archive it into a .zip file, it fails to find an outline. I cannot get the raw file to show up in a gerber viewer either, i cannot see it's size and shape at all using that file.

Is there anything i should be doing? I'd love to be able to order the Dummy PCB as well!

Sorry for the misunderstanding. I thought the problem was the "real" PCB. In the .zip file I linked you will find a KiCad file called "ayuda_corte_carcasa.pro". Can you use it to generate your own gerber file?

[buttersoft]

Hah, no i don't think so. I'm only using EasyEDA online PCB designer, i do not have kicad or anything else

[gambaman]

Hah, no i don't think so. I'm only using EasyEDA online PCB designer, i do not have kicad or anything else

You can also use EasyEDA. Just do the following:

-Extract the files "ayuda_corte_carcasa.pro" and "ayuda_corte_carcasa.kicad_pcb" from the previously linked zip file.
-Create a new zip with the files you extracted.
-Go to the EasyEDA menu and select document->Open->Kicad
-Select the zip file you have just created.

P.D: KiCad is libre and free. You can download it from https://www.kicad-pcb.org/

[buttersoft]

Ahhh, ok thanks! I've had such terrible time trying to import anything into EasyEDA i think i gave up. It's an awesome site, but not great for reverse-engineering anything, if i can use the term that broadly.

[buttersoft]

Hi Gambaman, I've been taking a look at your cool adapter, because i'm hoping to cut it down a little - i only need video and would like to keep the LED's. You mention in your first post that all the circuit strictly needs are the PIC, two resistors and two capacitors.

To keep the LED's as well, the components i seem to have left on the board are the PIC, along with R1, R6, R7, C1 and C2. Should there be another resistor, and if so, which one?

Are C1 and C2 just for power/noise filtering?

Thanks!

[gambaman]

Hi Gambaman, I've been taking a look at your cool adapter, because i'm hoping to cut it down a little - i only need video and would like to keep the LED's. You mention in your first post that all the circuit strictly needs are the PIC, two resistors and two capacitors.

To keep the LED's as well, the components i seem to have left on the board are the PIC, along with R1, R6, R7, C1 and C2. Should there be another resistor, and if so, which one?

Maybe you should also leave R5. It is used to lower the 5V of the PIC output to the nominal voltage of the RGB selection (pin 16 of the SCART connector). I think you will probably not break your TV if you connect directly the PIC output to SCART RGB selection, but just in case...

Are C1 and C2 just for power/noise filtering?

Yes. Maybe your implementation will work without them.

[gambaman]

With the current firmware, when the PIC detects a correct output, it waits for a long time before activating the output. Some testers say it is annoying because, when they switch to a game with a different resolution, the SCART input on the TV is disabled. I think it can be solved by modifying the firmware. In the source code there is a line like this "#define countdown_duration 30000". The SCART input will reactivate faster if you replace "30000" with a lower value (lower than 2300 and higher than the number of lines of your TV). I suggest mounting the PIC on a socket so that it is possible to test several values without desoldering it.

[buttersoft]

Thanks for the replies! I'm, using dedicated RGB sets like PVM's, so i won't need the SCART blanking voltage

I always like socketing IC's so i can fiddle later, but i hadn't thought of it in this case. That seems like a good idea. I'm no programmer, but I'll see what i need to do to get into the code - it's in C?

[gambaman]

Thanks for the replies! I'm, using dedicated RGB sets like PVM's, so i won't need the SCART blanking voltage

Then you may consider the previous version of the adapter. It uses a smaller and cheaper PIC. However, you will have to use this hack if you also want the LEDs.

I always like socketing IC's so i can fiddle later, but i hadn't thought of it in this case. That seems like a good idea. I'm no programmer, but I'll see what i need to do to get into the code - it's in C?

Yes. You can find the source code in the project page. Do you want me to change anything and recompile it?

[baritonomarchetto]

These projects are fascinating! The only drawback using pics is that you are in the need for programmers... Could you suggest a cheap programmer for pic16f18313?

[buttersoft]

EDIT: the TL866 variants do not work for this project, beware!

TL866ii? It's $60AUD, which isn't nothing, but it does so many different chips (including 27C322 roms with an adapter, used in Amiga, SNES and Genesis roms). That's the only time i've needed an adapter, everything else has worked immediately.

Thanks, Gambaman, i'll give the previous version a look. I'll take a look at the code and see if i can figure it out, but if not i'll give you a yell. Cheers

[gambaman]

These projects are fascinating! The only drawback using pics is that you are in the need for programmers... Could you suggest a cheap programmer for pic16f18313?

A friend of mine uses a cheap PICKIT3 Programmer.

[Zebidee]

Thanks for the replies! I'm, using dedicated RGB sets like PVM's, so i won't need the SCART blanking voltage

hiya buttersoft, you don't do any blanking for PVMs? I've found that my Sony PVMs need blanking. They seem happy with just bridging pin 20 (sync) to pin 16 (blanking) with a small wire, but they do need some voltage there. Or do you mean AV switching at pin 8? Yeah, think they won't need that.

gambaman - love your work!

[buttersoft]

No no, blanking. Most PVM's don't have SCART to begin with, but the 2730's have an option to turn "superimpose" off for the SCART socket - which means they're always in RGB mode. Unless that's superimpose on, but i think it's off.

[Zebidee]

No no, blanking. Most PVM's don't have SCART to begin with, but the 2730's have an option to turn "superimpose" off for the SCART socket - which means they're always in RGB mode. Unless that's superimpose on, but i think it's off.

Ahhhh, I'll have to fire up my PVM2730QM and try that out. At the moment it is gathering dust in my hot shed. I do recall the "superimpose" switch, but it didn't seem to do anything when I tested it - maybe because my VGA-SCART cable already had blanking voltage!

[buttersoft]

Hi Gambaman,

Alright, I can get into the file and change the parameter, (to 1000) but i'm stuck on how to compile. I've got an AVR toolchain and Git installed, but there's no makefile in your project. And i tried to install MPLAB X but it says there's a missing platform tool called noID which isn't in the downloadable plugins either... ;?

So, if you have any advice i'm all ears. I cannot believe how hard i'm finding it to compile c code, so any pointers would be awesome

I'd prefer to compile myself as that way i can test different values, to save asking you to compile a bunch of hexes for me to program.
Cheers!

[gambaman]

I can get into the file and change the parameter, (to 1000) but i'm stuck on how to compile. I've got an AVR toolchain and Git installed, but there's no makefile in your project.

Hi, buttersoft. I did not create manually the makefile. Instead, I used MPLAB X IDE.

And i tried to install MPLAB X but it says there's a missing platform tool called noID which isn't in the downloadable plugins either... ;?

Sorry, I don't remember if I had to install anything else.

So, if you have any advice i'm all ears. I cannot believe how hard i'm finding it to compile c code, so any pointers would be awesome

I'd prefer to compile myself as that way i can test different values, to save asking you to compile a bunch of hexes for me to program.

Anyway, in case you can not compile it I updated the source and compiled code. You can download it from the project page. I changed the parameter to 740 and works like a charm.

[buttersoft]

Hah, i figured it out. I stupidly followed a tutorial and it was doing the wrong thing!

Thanks though, i'll change to 740 and give it a run

EDIT: And now it seems my PIC's are on backorder until November Any chance there's another PIC the code can be programmed to? Or without too much trouble...

I have to admit all i did to compile was copy-paste-all from your main.c file. All i changed was the countdown duration, to 740, and my hexfile looks different to yours! It gives me a warning too, abhout an arithmetic overflow on line 78 ( NCO1INCL=NCO_increment;). Any ideas what i might be doing wrong there?

[gambaman]

EDIT: And now it seems my PIC's are on backorder until November Any chance there's another PIC the code can be programmed to? Or without too much trouble...

The previous version uses a PIC10F320/322. Does it suit you?

I have to admit all i did to compile was copy-paste-all from your main.c file. All i changed was the countdown duration, to 740, and my hexfile looks different to yours!

Click on File->Project Properties and check that the selected device is PIC16F18313.

It gives me a warning too, abhout an arithmetic overflow on line 78 ( NCO1INCL=NCO_increment;). Any ideas what i might be doing wrong there?

It is OK. It warns you because the constant NCO_increment does not fit in NCO1INCL so only the 8 least significant bits will be written there. It is the wanted beahaviour. Note that the other bits are previously stored in NCO1INCH and NCO1INCU.

[buttersoft]

baritonomarchetto I made a big mistake! IT doesn't look like the TL866 can program the PIC16F18313. I'm going to have to grab that one Gambaman recommended, i think.

[gambaman]

baritonomarchetto I made a big mistake! IT doesn't look like the TL866 can program the PIC16F18313. I'm going to have to grab that one Gambaman recommended, i think.

I'm sorry to hear that. Was it very expensive?

[buttersoft]

About $25 AUD. I grabbed the exact one you linked to as it seemed to come with the better ZIF-socket adapter. I couldn't use the other PIC10 chip in your simpler adapter either, i'd need the programmer for that too. The worst part is waiting 6 weeks for it to arrive :/ I do plan to make a few of these SCART adapters, and play around with the design. And i'm sure i'll want to program something else in future.

I'm still a bit overwhelmed by MPLAB X IDE though, but i think all i need to do is import the .hex file, then build the project, using the programmer as the device. The target IC being a PIC16F18313 should already be set up, yes?

Also, i was half planning to use this for the MiSTer. Do you know if the H-sync input for the PIC16F18313 will pass composite sync through? Does it depend on what the v-sync port is doing as well?

Also, great avatar! I have to steal that picture