VGA

[Electroguard]

This post is mainly to start a new VGA thread because the original VGAout thread grew so big... [Local Link Removed for Guests]

But it is also to broaden VGA horizons, by showing that Annex VGA does not necessarily require using a "large VGA display", as mentioned elsewhere.
Mind you, a decent-sized wall-mounted monitor is great for displaying useful info, which is why I already have four dotted around (mainly for CCTV), and another 'VESA' wall mount ordered just for Annex to display clock/calender and local weather etc.

vesa1.jpg

There are cheap VGA converters available which allow VGA output to be connected to other types of non-vga displays.

vga2rca.jpg

This video clip shows Annex32-S3 VGA connecting via a 5 quid VGA2AV converter to a 20 quid dual input 7" AV display which I normally use to keep an eye on the Gate Cam CCTV... https://odysee.com/@Electroguard:d/vga2av:5

7%22mon.jpg

4.3.jpg

I could similarly use an AV converter for a 4.3" AV display which I normally keep for carrying around to align cameras.

4.3displayA.jpg

The point is that there are plenty of small cheap displays available which can be driven by a cheap VGA converter.
Car reversing monitors range from 3.5" for about a tenner, up through 4.3" or 5" for about 15 quid, or 7" for about 20 to 25 quid.

Incidentally, a 5 quid mains to 12v cigarette lighter socket can be handy for quickly checking 12v car items at home.

CiggySkt.jpg

vga2hdmi2.jpg

VGA to HDMI converters are available for a fiver, making it possible to use Raspberry Pi 7" HDMI touchscreens, which are available for about 55 quid.
And there are plenty of bigger HDMI touchscreens available for bigger pockets. As with CiccioCB's excellent TFT.GUI components, all the VGA.GUI components I have tried work like a charm, but I've not been able try any of the VGA.GUI touch components yet.

pi7%22touch.jpg

At the other end of the scale, a cheapo VGA to HDMI converter connected to a spare HDMI input on our large screen TV (or by adding a cheap HDMI switch) allows switching a big screen between eg: Annex VGA local weather, Cable, SAT, CCTV, computer, etc.


A word of caution, rather than making quick careless assumptions about products, better to check them out to avoid disappointments.
Not many asian sellers are english experts, and may just be parroting wholesalers info while mentioning several different products in the same title.
So it is up to you to ensure you are ordering eg: a VGA to HDMI converter instead of an HDMI to VGA converter.

vga2bnc.jpg

Although AV (RCA phono) and BNC (composite video) look and sound totally different, they can usually be connected together using an appropriate BNC/phono adapter. Be aware though that although 75 ohm TV BNC connectors look almost identical to 50 ohm Network BNC connectors, the internal insulated connectors are recessed by different lengths - so you may not be worried about impedence matching, but if they are physically mismatched they either won't clip together or else will be loose and not make proper electrical contact. No point knowing what to ask for, cos most asian sellers would not understand the question nor give a useful answer.
If in doubt, just join yourself a cable together.

bnc.jpg

[Electroguard]

I noticed that you previously changed VGA pin assignments Francesco, was it because of any problems ?

Or to ask a better question... if I was trying to keep the VGA pins closer together, either in a line, or two groups opposite each other, are there any suggestions, or pins to avoid ?

I am using top-mounted female headers, so basically I want to create a 'resistor saddle' to plug-in the vga cable without taking up all the device footprint.

ESP32-S3_DevKitC-1_pinlayout_v1.1s.jpg

[cicciocb]

I noticed that you previously changed VGA pin assignments Francesco, was it because of any problems ?

Or to ask a better question... if I was trying to keep the VGA pins closer together, either in a line, or two groups opposite each other, are there any suggestions, or pins to avoid ?

I am using top-mounted female headers, so basically I want to create a 'resistor saddle' to plug-in the vga cable without taking up all the device footprint.



ESP32-S3_DevKitC-1_pinlayout_v1.1s.jpg

I changed the wiring simply because the pins I choose are all straightly in line.
I wired also an SDCARD, a TFT, an I2S DAC and an I2C connector.
I wired on a little PCB, so It was easier to connect the pins just in face.
You can choose the pin as you want, probably if you want to use the ADC or the touch, this is not possible on all the pins so your choice can be different.

[Electroguard]

That's good to know, thanks, I can have a play with the pin-out in peace of mind.

[Electroguard]

Hi Francesco,
The external RGB resistors evidently set the RGB colour weighting, but is their also any internal software weighting involved ? Perhaps timings ?
The reason I ask is because the 8 colour 3-wire combined resistance is different from the 256 colour 8-wire combined resistance.
I only found out cos my white is more like a tobacco stain, so I went back to basics with a 3-wire test rig using three 1K trimpots initially set to 330 ohms, then adjusted for improved white. That worked well, with r=330, g=330, b=245 giving a better white, and r=390, g=400, b=215 giving the best white.

But to translate that into 8-wire resistances I needed to create a tool for calculating parallel resistances (I'll post it after a cleanup if anyone wants it).
At this point it is worth mentioning that a change of vga.pinout syntax might make usage easier and more consistent by having most important to least important, eg:
3-wire: vga.pinout R1, G1, B1, H-sync, V-sync
8-wire: vga.pinout R1, R2, R3, G1, G2, G3, B1, B2, H, V
Anyway, it made it easier for me calculating resistor values, where...
R1, G1, B1 are appropriate selected resistances, R2=R1*2, G2=G1*2, B2=B1*2, R3=R1*4, G3=G1*4

I added 400 and 500 to the preferred resistance value range so I could use them as the prescribed starting defaults, but then noticed that the resulting r=286, g=286, b=267 parallel resistances did not match the 3-wire 330 resistances.
Also, my newly chosen optimised resistances are very different to the originals - none of which matters if that's what gives best results.
But before soldering in the new optimised resistors I just want to check there is no additional internal compensation or weighting to be aware of ?

defaults.jpg

newRs.jpg

[cicciocb]

Hi Robin, the output are simply digital outputs and there is no internal compensation. The only difficulty is that there are only 2 bits for the blue, that create a difficulty into matching the level of the voltage of the blue with the other colors. Ideally we should use a real DAC because each digital output can produce a slightly different voltage so don't hesitate to find the values of the resistances that works for you. This could also be function of the monitor. Do not forget that you can, eventually, modify the colour intensity into the advanced parameters of your monitor.

[EasyRider]

My personal input regarding VGA support.

I personally don't see much value in VGA support without GUI input support, be it simple PS2 mouse and or keyboard.

This post is not intended in any way as a negative feedback for existing VGA "Output Display" development and people supporting it.

[Fernando Perez]

EasyRider, once you had the possibility of entering data via keyboard or mouse (which I would prefer to be USB instead of PS2), what would you do with them?
Do you have a project or idea to contribute to justify your request?

[Electroguard]

My personal input regarding VGA support.

I personally don't see much value in VGA support without GUI input support, be it simple PS2 mouse and or keyboard.

This post is not intended in any way as a negative feedback for existing VGA "Output Display" development and people supporting it.

No negative feedback assumed EasyRider, just some positive feedback offered:
VGA output offers the optional additional advantage of greatly increasing the range of display devices available to Annex for those who may need it.
And it should be said that if VGA touchscreen is as effective as TFT touchscreen, then GUI input support can't get much better than that.

Lack of PS2 mouse and keyboard applies to all types of displays that Annex supports, and you'll be a busy boy if voicing similar comments against everything else that you have no personal use for. So let's avoid negatives and see if we can come up with any useful input methods - and best to forget about VGA, because everything applies equally to all display types.

Firstly, it must be said that an ESP device is not best suited to adding a physical keyboard and loading a large character set into memory which must be decoded and interpreted for every shifted or non-shifted key-press - and that's before even attempting to do anything with the character that was input.

But it is easy to add a navigation keypad, either for menu selection, or to select virtual characters from your own web-page or on-screen keyboard.
Stick-on keypads are cheap and neat, either touch or tactile buttons, and either individual gpio keys or matrix.
Serial to PS2 mouse adapters basically allowed connecting a serial mouse via the computers PS2 mouse port.
It would not be difficult to connect a serial mouse to Annex to read the button and 2 analog inputs.
Similarly for a serial trackball, or serial joystick.
A PS2 play-station game controller has 2 serial joysticks, plus nav buttons, all sent via a single serial link - so a serial monitor can show what is what.
A swipe gesture controller is another option for menu control.
Infra-red remote control is a good cheap neat option, with the added bonus that a 'multi=page' remote controller could be programmed with existing remotes (which could then go in a cupboard) then add the new Annex nav controls, all on the same IR controller.

So as a balanced summary, even though size and availability of VGA monitors may offer no personal advantage, VGA certainly causes no disadvantage, and it already benefits from all input methods available to all of the other display devices.

[EasyRider]

Do you have a project or idea to contribute to justify your request?

I did not make any requests regarding VGA, only my personal thoughts regarding VGA support as a display "OUTPUT" only!
Maybe you guys have better use for VGA display output only, that I can't personally see for myself.

YES, VGA to me would be good if it can be used interactively like ALL other "Touch" LCD/TFT, etc" displays. I only suggested Mouse and Keyboard as an input device, because as far as I know most of large VGA displays don't support touch.
I am looking for interactive GUI possibility like ALL other touch screen support. I use ILI9341 touch extensively and "Large" VGA interactive GUI would be great.

YES, I know its possible for end user to interface a very simple navigating keypad and to write BASIC code to provide input and GUI control, but that is not the same as firmware implemented GUI support.

As I said before, I am not here to criticize or demand, only offering my personal thoughts. This is not a request,