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Topic: VGA library - now with TV output (Read 32314 times) previous topic - next topic

BKnight760

@Stimmer,
    I updated the circuit using the closest resistors I could find handy.  It didn't make much difference to the overall picture.  It's still just greyscale; no color whatsoever.

   I also tried to use a different TV in the house which is much newer (late '90s, early 2000s).  The picture stability was better, but the output was still black and white. 

    I'll try to get some digital pictures of my circuit and the TV output and post on here.

BKnight760

BKnight760

I uploaded the "DrawingTestNTSC" sketch provided with the library.  It also comes out black and white on both TVs.

stimmer

Which version of the Arduino software are you using? I'm using 1.5.6r2 on Linux and it is working in colour on a fairly recent monitor (although is has to be said that the picture quality is not very good - if you know what 8-bit computer TV output used to look like in the 80s you'll know what to expect; if not, be prepared to lower your standards :) )

Make sure you are connected via the programming port - the NTSC code clashes with the Native port causing flicker and hangs.
Due VGA library - http://arduino.cc/forum/index.php/topic,150517.0.html

BKnight760

I'm using Arduino IDE version 1.5.3.  After uploading the sketch, I disconnect the Arduino board from the computer entirely.  I have it connected to the TV via the RCA cable, and to the power outlet via the DC barrel jack.  I'm feeding it the picture data from a second Arduino over software serial.  So, the data comes in on Serial1 on the DUE.  Would using the second hardware serial port conflict with it somehow?

    The picture quality isn't an issue here.  I know what the resolution and color palette is, and am aware that the graphics will look somewhat old-school.  I did graphics programming in BASIC in 4 colors on an 8088 computer a long while back, and this is certainly better than that.  I can mess with the color palette once I get it to display any color at all.


stimmer

Serial1 shouldn't cause a problem, it's no worse than using Serial via the programming port and that works fine.

It just sounds like the signal generated is too far out of spec for a TV that old. Those TVs use crystals in the colour circuit so the signal has to be accurate to a few ppm - newer TVs do the NTSC decoding on a FPGA/ASIC and the signal can be out by almost 1% and it still gives colour.

Unfortunately this is not something I am likely to fix. The code for the library is getting too difficult to maintain. If I did it all again I now know better ways to get a more accurate signal (and more easily maintainable code)
Due VGA library - http://arduino.cc/forum/index.php/topic,150517.0.html

facundoo

I need output to VGA but in Mega 2560.
Is possible?

Frédéric_Plante

#66
May 07, 2014, 04:37 pm Last Edit: May 07, 2014, 04:45 pm by Frédéric_Plante Reason: 1
Hello Stimmer

I was looking around the net before starting to weld my VGA wire, cause I always look before do. And I have note that the is a DDC I2C signal Chanel on the connector at pin 12 and 15.

http://en.wikipedia.org/wiki/VGA_connector

My question is, in the near future, do you plan to exploited it in a future version of you library? And if so, what colour of Wire do you plan to use? Usually, my I2C use Grey(SDA) and Brown(SCL).
As we fight our way northward into the great unknown, only that one thing remains certain...

stimmer

I wasn't going to add VGA I2C support to the library itself. I guess if someone else did I could add the code as an example but it wouldn't be part of the core library.

I've not had much success with I2C on the Due - I can't get any I2C device to work! I think the VGA I2C is just an EEPROM which should be quite simple. Processing the data from the EEPROM is harder - getting the make and model strings is quite easy, getting the sync ranges and native resolution is more difficult.
Due VGA library - http://arduino.cc/forum/index.php/topic,150517.0.html

Frédéric_Plante

Well I have this on my list,

Finish the tlg10ua03 procedure explaining
Get this ov528 cam thing to work

Then I will start this, since the DUE has finally got in I will be able to co-experiment. ;)
As we fight our way northward into the great unknown, only that one thing remains certain...

pfergiu

Hi Stimmer
In first place, great work!
I have an Arduino Mega 2560. Is it possible to run DueVGA on my board?
Thanks in advance

viperML

Is this working in Mega 2560 ??  :)

adyn

#71
Sep 27, 2014, 10:58 pm Last Edit: Sep 27, 2014, 11:10 pm by adyn Reason: 1
This is a great library. I was able to use it with VGA as well as NTSC. There is one issue. If I try to use this in conjunction with USB host library on Arduino Due it works in VGA mode but not in NTSC mode. If I start VGA.beginNTSC() both libraries are going to stop working..

...Just checked the code and I saw this notice:
// Doesn't work well with Native USB

Hm, this seems to be a known fact. Anyway any idea why? Can anybody help?

Frédéric_Plante

I have use this library having great pleasure. The gps example is a wow case congratulation. I tryed it with the waveshare vga/ps2 module that offere 9 bits colors but still work great in 8 bits color, leaving th high blue not connected.

http://www.aliexpress.com/item/VGA-to-VGA-module-PS2-PS2-module-module-test-module-adapter-board-development-board/1872558241.html



How ever,  since there is also a PS2 port on the module, I tryed it in conjonction with the vga library, I confirm by the way that the PS2 keyboard library work on DUE, but when we use it with your library, the picture on the VGA screen strart skipping when we press a key.

I suspect that it is caused by the fact that the PS2 library use an interrupt to catch the clock signal frome the keyboard. But I was expecting that the DUE would go over that using it's multitasking aspect.

Any way, I just want to signal this bug, incase any one has an idea on how to overcome this problem.

Cheer!
As we fight our way northward into the great unknown, only that one thing remains certain...

est_cap


I have use this library having great pleasure. The gps example is a wow case congratulation. I tryed it with the waveshare vga/ps2 module that offere 9 bits colors but still work great in 8 bits color, leaving th high blue not connected.

http://www.aliexpress.com/item/VGA-to-VGA-module-PS2-PS2-module-module-test-module-adapter-board-development-board/1872558241.html



How ever,  since there is also a PS2 port on the module, I tryed it in conjonction with the vga library, I confirm by the way that the PS2 keyboard library work on DUE, but when we use it with your library, the picture on the VGA screen strart skipping when we press a key.

I suspect that it is caused by the fact that the PS2 library use an interrupt to catch the clock signal frome the keyboard. But I was expecting that the DUE would go over that using it's multitasking aspect.

Any way, I just want to signal this bug, incase any one has an idea on how to overcome this problem.

Cheer!


Hi! I've had a VGA-PS2 module for quite a while and never used it because it didn't fit in my breadboard, but today I got a bunch of male-female wires to be able to wire it up. I have allways used the DueVGA library as explained in the documentation with the resistors, but this module seems really usefull.

Could you tell me if you made any modifications? The one I have is this one: http://www.wvshare.com/product/VGA-PS2-Board.htm and I guess it's the same you have.
I would be grateful if you could help me understand how to wire this.

Frédéric_Plante

Hi for high resolution it' simple you simply use R G B directly to the SPI MOSI

For color low res, I dont have the module with me since i'm not home, but check out the resistor value on the board and place the RED BITS in so it match le library reqirement same for GREEN. For the blue part, i was satisfy by using the 2 lowest pin BLUE 1 AND 2, but you might want to try all the combination. But one thing is for sure, the library only handle 2 BLUE and not 3.
As we fight our way northward into the great unknown, only that one thing remains certain...

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