VGA out for ESP32-S3 - New feature to test

Post by **cicciocb** » Wed Jul 12, 2023 5:15 pm

As discussed into another post, I'm introducing a new feature for the ESP32-S3.

The VGA out enables the use of an external VGA monitor as a graphic output for the module.

This works only under the following conditions :
1) The module must be an ESP32-S3 with PSRAM
2) The module must have the FLASH and the PSRAM with octal interface (opi / opi)
3) The modules with quad FLASH (qio) and octal PSRAM (opi) will work too but with some limitations on the resolution

The color depth has been defined at 8 bits for a max of 256 colors.
The scheme is 332 (3 bits for red, 3 bits for green, 2 bits for blue)

You'll find below a preliminary schematic for the wiring

image.png

For the initial test, the wiring can be done for achieving only 8 colors with this simplified wiring

image.png

For this initial testing, the colors are always defined as 16 bits (same as the TFT) but only the most significant bits will be used.

II'm still in the development so I'll continue in few minutes

Post by **cicciocb** » Wed Jul 12, 2023 6:26 pm

Please find here the following .bin

This is for ESP32-S3 with QIO FLASH and OPI PSRAM; any other combination will not work

Annex32S3.bin

I included also a little series of examples I'm using for the testing.
Not all work but can be a good baseline to understand

examples_VGA.zip

The very synthetic documentation :

image.png

Video modes table

image.png

Do not hesitate to ask, I'm still working on and this is just a very preliminary release

Electroguard · Post by **Electroguard** » Wed Jul 12, 2023 10:29 pm

Firstly... wow Franc, thank you for all the huge work you keep putting in to Annex, I don't know how you find the time and energy.
I need to finish off the wiring of the multiple 0vs tomorrow before I can actually test the output, but I have upgraded the N16R8 to 1.50.5
A couple of feedback points...

The Multiplatform Toolkit Advanced Options defaults to 40Mhz, so I changed to 80Mhz cos I assumed that fastest is best.

toolkit.jpg

I flashed using the Green button, but anyone needing existing contents should save them first, cos the new LFS will overwrite.
The new LFS File Manager is great BTW, uploaded the vga examples zip no problems.

update2s.jpg

Post by **cicciocb** » Thu Jul 13, 2023 7:57 am

[Local Link Removed for Guests] wrote: [Local Link Removed for Guests]Wed Jul 12, 2023 10:29 pm Firstly... wow Franc, thank you for all the huge work you keep putting in to Annex, I don't know how you find the time and energy.
I need to finish off the wiring of the multiple 0vs tomorrow before I can actually test the output, but I have upgraded the N16R8 to 1.50.5
A couple of feedback points...

The Multiplatform Toolkit Advanced Options defaults to 40Mhz, so I changed to 80Mhz cos I assumed that fastest is best.

toolkit.jpg

I flashed using the Green button, but anyone needing existing contents should save them first, cos the new LFS will overwrite.
The new LFS File Manager is great BTW, uploaded the vga examples zip no problems.

update2s.jpg

Hi Robin,
thanks for the feedback.

Yes, you can select 80MHz even, if I understood correctly, this do not matter as this concerns only the speed of the bootloader and then the real speed is defined inside the .bin (I'm not really sure about that

).

I confirm that the new LFS file system delete all the existing files if the module was in FFAT format but you'll notice that now is much faster than before; I think that you noticed how fast you can import the files from the zip package.

Enjoy the testing, I have some other demo program that I'll try to send you later today, just to show the possibilities of the VGA output.

What I can say is that is very stable but, on the modules with QIO Flash (the one that you have), the resolution is limited at 640 x 480 that is a very good result considering that all is done without any interface.
It seems a little bit complicated the way I'm actually using to define the video modes (using a lot of parameters) but this is mainly because I'm exploring the different combinations with different VGA monitors.
The reason is because the actual frequency selection do not permit to have the exact frequencies required to comply with the VGA standard so some monitors works and other don't but all works when selecting the parameters within their own tolerances.
I'll obviously simplify the whole at the end with an unique "mode" parameter.
Another big advantage is that, as the DMA process use the PSRAM that is 8MB

, it is possible to have several buffers and manage them to have different layers to have transparent texts, sprites, etc.

Another advantage is that, as all relies on an H/W module contained inside the ESP32-S3, there is practically no impact on the CPU performances

Electroguard · Post by **Electroguard** » Thu Jul 13, 2023 12:33 pm

Perhaps may help others also...

vgabothc.jpg

Electroguard · Post by **Electroguard** » Thu Jul 13, 2023 2:49 pm

Should newfile11.bas be expected to work on my simple setup ?
I didn't see an example of vgaout.pinout being used, so to make sure the configuration matched with the single R,G,B plus H and V sync pins which I connected as per the picture, I added vgaout.pinout 8, -1, -1, 14, -1, -1, 21, -1, 1, 2 line as per instructions.
The only other change was to add wlog r to confirm script was running, cos not seen anything on the vga monitor when running any of the examples.

The Dell monitor was in use with a 2nd computer until I swapped in a vga extension cable from the N16R8 connections, and its screen-saver is moving.
I can butcher another vga cable if necessary, but want to check whether the script configuration might be wrong first (or perhaps my N16R8 is not suitable).

newfile11b.jpg

monitor2.jpg

Post by **cicciocb** » Thu Jul 13, 2023 3:14 pm

The hardest part is starting ....

- Do not change the setting for the pinout, you can even suppress the line as, by default, is configured as per the schematics.

- If you want use it, the correct command is vgaout.pinout -1, -1, 8, -1, -1,14, -1, 21, 1, 2

- Do not use the examples where the vgaout.init is present, try the others. As I said not all the examples work.

- use the command vgaout.delete each time you change the mode otherwise the mode will not be taken into account

Post by **cicciocb** » Thu Jul 13, 2023 6:00 pm

Some images shown directly on a VGA monitor at 256 colors.
The result is nicer than I was expecting ...

Electroguard · Post by **Electroguard** » Thu Jul 13, 2023 7:47 pm

The picture looks great, shouldn't you put the top down on your car though in case it rains!

I went through all the vga examples, and tried everything without vgaout.setup, but my monitor has never even winked at me once, just a permanent scowl. I need a basic vga example that would make any vga monitor give an encouraging wink as-is.

I'll try to find a different vga cable, but all the kvm ones I have found are like tow ropes.

I also should try some different resistor values ... which were all neatly sorted out into drawers according to range (100R+, 1K+, 10K+, 100K+ etc), but the glue on the useless tape across the ends has dried out in the heat, so now each drawer just contains a prickly unreadable tangled 1/8W mess.
Need to be ordering a range of 1/2W resistors that don't need tweezers and microscope, but my resistor tolerance is pretty low at the moment.

(that is a very impressive and encouraging 640 x 480 picture demo, BTW)

Post by **cicciocb** » Thu Jul 13, 2023 8:20 pm

The value for the resistors is not really important, in particular for simple 1 bit RGB, you could even connect directly without them, you'll just have an over-saturated image.

The classic questions :
- have you checked the wiring?
- have you tried with another monitor?

Sometime the monitor is not able to catch the format but could show a message like "out of sync" ; this is a good sign.

The minimal example is very very simple :