CubieBoard Forum

Cubieboard itself => Hardware => Cubieboard v1 Hardware (A10 Based) => Topic started by: lawrence on February 13, 2013, 04:04:09 am

Title: VGA from Cubieboard
Post by: lawrence on February 13, 2013, 04:04:09 am
Wiki is incorrect - http://linux-sunxi.org/Cubieboard
(Pin 33,35 are labelled wrong).
Wiki fixed now.



Board pin out provides LCD-HSYNC / V-SYNC - not VGA-HSYNC / V-SYNC.
We do have RGB VGA out though.


So you'll need to use a chip to convert the levels to VGA-HSYNC / V-SYNC
Pins are as follows:


(From cubieboard)

pin 25 ground - VGA 5,6,7,8,10
pin33(LCD-VSYNC) -> 74AHCT04 -> VGA PIN 14
pin35(LCD-HSYNC) -> 74AHCT04 -> VGA PIN 13
pin 27 red -> 75ohm -> VGA PIN 1
pin 29 green -> 75ohm -> VGA PIN 2
pin 31 blue -> 75ohm -> VGA PIN 3

Circuit diagram (see attached), or look at the pretty picture served via flickr:

(http://farm9.staticflickr.com/8531/8469712355_e0da4b0562_z.jpg) (http://www.flickr.com/photos/sheedl/8469712355/)
vga_cubie (http://www.flickr.com/photos/sheedl/8469712355/) by sheedl (http://www.flickr.com/people/sheedl/), on Flickr
Title: Re: VGA from Cubieboard
Post by: naatamam on February 14, 2013, 11:59:15 am
hi
my VGA Circle for Cubieboard
(http://digitalcontrol.persiangig.com/gallery/Vga4Cubieboard-2.JPG)

http://www.iranmicro.ir/forum/showpost.php?p=62410&postcount=402 (http://www.iranmicro.ir/forum/showpost.php?p=62410&postcount=402)
Title: Re: VGA from Cubieboard
Post by: iranmicro on February 22, 2013, 01:48:13 am
VGA and Good woking for me.
wiki is incorrect tnx alot lawrence
and config for vga (edit script.bin)
Code: [Select]
[disp_init]
disp_init_enable = 1
disp_mode = 0
screen0_output_type = 4
screen0_output_mode = 4
screen1_output_type = 2
screen1_output_mode = 14
fb0_framebuffer_num = 2
fb0_format = 10
fb0_pixel_sequence = 0
fb0_scaler_mode_enable = 1
fb1_framebuffer_num = 2
fb1_format = 10
fb1_pixel_sequence = 0
fb1_scaler_mode_enable = 1

http://www.iranmicro.ir/forum/showpost.php?p=62982&postcount=519
Title: Re: VGA from Cubieboard
Post by: lawrence on February 22, 2013, 04:38:09 am
Well done!
Title: Re: VGA from Cubieboard
Post by: naatamam on February 22, 2013, 01:09:42 pm
HI
my good test VGA & CVBS  (Androide And Linaro)

(http://digitalcontrol.persiangig.com/gallery/Test%20CVBS%20or%20VGA-01.jpg)
(http://digitalcontrol.persiangig.com/gallery/Test%20CVBS%20or%20VGA-02.jpg)
(http://digitalcontrol.persiangig.com/gallery/Test%20CVBS%20or%20VGA-03.jpg)

HDMI PIC (LINARO)
(http://digitalcontrol.persiangig.com/gallery/03.jpg)
Title: Re: VGA from Cubieboard
Post by: GeorgeIoak on February 22, 2013, 03:33:45 pm
Looks like some good work. What Linaro image are you using? Does your kernel have the Mali drivers loaded? I'm using the same VGA circuit and have not been able to get an image
Title: Re: VGA from Cubieboard
Post by: GeorgeIoak on February 22, 2013, 05:22:57 pm
Sorry, I mis-read Lawrence's post about the pin change. i should be good now that i know to use the other set of sync signals
Title: Re: VGA from Cubieboard
Post by: naatamam on February 22, 2013, 05:47:22 pm
see help for vga Error  AND script for VGA Display linaro
http://www.iranmicro.ir/forum/showpost.php?p=62982&postcount=519

Download imag Linaro ubuntu 12.04 (Made by Iranians)
http://www.iranmicro.ir/forum/showpost.php?p=62912&postcount=504

Test Vga & Cvbs Deployment Cubiboard Ver 2.30
http://digitalcontrol.persiangig.com/weblog/neviseh_1361551106.html
or
http://naatamam.blogfa.com/post-1924.aspx


Title: Re: VGA from Cubieboard
Post by: OmahaVike on February 27, 2013, 09:43:51 pm
Personally, I'd rather take a flogging than to manually wire this stuff up.  But I sincerely admire you all for taking the initiative.

I took a different route and bought this:

http://www.amazon.com/gp/product/B007SM7O2U/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1

It works *perfectly* for the stock Android distro.  Picked up my monitor settings and came in full screen.  I tried it also on the Linaro Desktop and it appears as if there will need to be some Xorg (or whatever they use) configuration adjustments.  Same for Linaro's Ubuntu Server terminal -- although, that really wasn't a surprise.

If you want my monitor's specs, just let me know.  I'm currently typing this away on my kids computer for which my key clicks are my childrens' lullaby.
Title: Re: VGA from Cubieboard
Post by: vasek_blr on March 03, 2013, 03:15:50 pm
naatamam, can you show your's PCB? it was great if you told more and show your configs for different connections.
Title: Re: VGA from Cubieboard
Post by: vasek_blr on March 03, 2013, 03:29:02 pm
Iranmicro, can you show your schematic? You use 27 and 30 pin's from another connector?
Title: Re: VGA from Cubieboard
Post by: iranmicro on March 06, 2013, 06:24:45 am
yes,
Title: Re: VGA from Cubieboard
Post by: ircan on March 10, 2013, 06:16:51 am
Hi, on revision 09-09 working vga without this chip from pins 27,30 from other connector with default android distro...
But I dont have other Linux mashine, pls can somebody upload upgrated script.bin for linaro or berryboot for boot on VGA?
Title: Re: VGA from Cubieboard
Post by: vasek_blr on March 11, 2013, 01:55:13 pm
Get this =)
Title: Re: VGA from Cubieboard
Post by: vasek_blr on March 11, 2013, 01:57:20 pm
VGA work after switch in android? I don't have hdmi and cant switch, where is setting's file in android?
Title: Re: VGA from Cubieboard
Post by: Dariush on March 11, 2013, 02:42:52 pm
You should configure the "sys_config1.fex" file in order to enable VGA.
Or use CVBS and then switch to VGA in android itself.
Title: Re: VGA from Cubieboard
Post by: ale92_ on March 16, 2013, 05:08:40 am
hi,
which circuit do you recommend, the one from the first post or the one from the second?

i'm leaning towards the first because seems easier, any suggestion?
Title: Re: VGA from Cubieboard
Post by: leet on March 16, 2013, 07:30:38 am
Greetings ...

 Silly question, if I want EDID support in my VGA adapter, do I need a level shifter for the I2C/EDID/[SDA/SDC] lines?  I see the lines marked on the second circuit, but missing on the first.

 I have been warned about connecting the SDA/SDC lines to the Cubie, because I might need a level shifter, but I can't find any details about voltage for either DDC on VGA or I2C interface on Cubie.  I know on some I2C device been connected to Arduino the difference between 3.3V and 5V is a problem, so a level shifter is used.

Thanks
LeeT
Title: Re: VGA from Cubieboard
Post by: lawrence on March 18, 2013, 09:33:30 am
http://pinouts.ru/Video/VGAVesaDdc_pinout.shtml

If you want EDID for the VGA side, you'll probably need to write code for it too.

Currently you set resolution via fex or fbset over VGA vs reading whats supported.

I've only had it working with R,G,B, and sync lines, haven't tried anything more adventurous.  Haven't really seen the need either.. (although I do need to set lower frequencies for my own use at some point)
Title: Re: VGA from Cubieboard
Post by: iranmicro on March 20, 2013, 06:17:14 am
@   lawrence
I see cubiebase board use lcd1 HS/VS
I think not work for vga
!!?https://store.iotllc.com
Title: Re: VGA from Cubieboard
Post by: GeorgeIoak on April 03, 2013, 10:00:51 pm
Quote
@   lawrence
I see cubiebase board use lcd1 HS/VS
I think not work for vga
!!?https://store.iotllc.com

My baseboard was designed before the problem was found on the Wiki for the connection. A simple modification on the intial boards allowed the VGA to work. This has been changed  in the design now.
Title: Re: VGA from Cubieboard
Post by: ariee on April 05, 2013, 12:49:55 pm
I made a summary how to create VGA out for cubieboard.
Just check from this link http://taqlim.blogspot.de/2013/04/vga-out-for-cubieboard.html

I have tested my circuit and works just fine. :)
Title: Re: VGA from Cubieboard
Post by: safari on April 09, 2013, 11:55:16 am
Hi, on revision 09-09 working vga without this chip from pins 27,30 from other connector with default android distro...
But I dont have other Linux mashine, pls can somebody upload upgrated script.bin for linaro or berryboot for boot on VGA?
ircan, what is revision 09-09, is not it (https://dl.dropbox.com/u/8635482/img/IMG_0509.JPG)?
Title: Re: VGA from Cubieboard
Post by: safari on April 11, 2013, 01:28:34 am
O, yes! A have connected VGA with only 3 resistors.
Without resistors there are noise bars.

Title: Re: VGA from Cubieboard
Post by: ircan on April 11, 2013, 12:52:27 pm
Yes, your picture is revision 09-09...
Title: Re: VGA from Cubieboard
Post by: diogoc on June 06, 2013, 05:45:24 am
After reading this I get confused.
The VGA-HSYNC/VSYNC should not be on pins 33 and 35 of the connector U15?
Or only works on pins 27 and 30 of the connector U14? It is not possible to change the configuration of the pins?

I have revision 09-09.
Title: Re: VGA from Cubieboard
Post by: ryba84 on July 17, 2013, 11:07:09 am
I tested it and VGA works only on pins 27 and 30 U14 connector. To connect VGA monitor we only must have 3 75ohm resistors, one for each color.
Title: Re: VGA from Cubieboard
Post by: drkbcn on July 17, 2013, 02:53:48 pm
Personally, I'd rather take a flogging than to manually wire this stuff up.  But I sincerely admire you all for taking the initiative.

I took a different route and bought this:

http://www.amazon.com/gp/product/B007SM7O2U/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1

It works *perfectly* for the stock Android distro.  Picked up my monitor settings and came in full screen.  I tried it also on the Linaro Desktop and it appears as if there will need to be some Xorg (or whatever they use) configuration adjustments.  Same for Linaro's Ubuntu Server terminal -- although, that really wasn't a surprise.

If you want my monitor's specs, just let me know.  I'm currently typing this away on my kids computer for which my key clicks are my childrens' lullaby.

I make Cubieez RC2 (Debian) to work properly with this one:

http://www.raspipc.es/public/home/index.php?ver=tienda&accion=verArticulo&idProducto=1083

Seems the same product but "white branded". It's an easy way to get VGA :)
Title: Re: VGA from Cubieboard
Post by: elpeibel on September 25, 2013, 12:26:21 pm
hello,

need some help. I don't know what i'm doing wrong.

I have a 09-09 revision from factory. I connected 30 and 27 U14 directly to monitor, R, G and B with 75 ohms "pull down" resistor and GND to pin 25 U15.

When I switch on the board the monitor switch on but I only see some white lines blinking randomly (is this noise bars?).

Title: Re: VGA from Cubieboard
Post by: diogoc on September 26, 2013, 03:41:00 am
Are you running android or linux?
Do you have changed the script.bin?
Title: Re: VGA from Cubieboard
Post by: elpeibel on September 27, 2013, 07:16:17 am
ok. I'm working trought VGA


i had no really edit script.bin... so thanks and sorry
Title: Re: VGA from Cubieboard
Post by: ipetrovic11 on October 09, 2013, 04:44:13 am
I am confused now.

Which is right solution? Only 3 resistors or with (74AHCT04)?

What does 74AHCT04 is for anyway? does it just make signal stronger or does it change anything?
Title: Re: VGA from Cubieboard
Post by: ipetrovic11 on October 10, 2013, 02:13:25 pm
Ok here is update:

I made it only with 3 resistors connected to the ground and it is working.
I also used 27 and 30 pins for Sync.

It is working ok, I still have to check different resolutions and few things but it is ok for now.

Thx safari and ircan for help
Title: Re: VGA from Cubieboard
Post by: JuSchu on November 16, 2013, 05:31:17 pm
I've got a few questions about the circuit from lawrence.
I'm from Germany and it looks like I can't buy the SN74AHCT04 here.
But I found the SN74HCT04 in a german shop:
http://www.produktinfo.conrad.com/datenblaetter/150000-174999/150134-da-01-en-CMOS_IC_SN74HCT04N__DIP14__TID.pdf
Can I use this IC instead? According to the datasheet the pins are the same.

But after I saw the datasheet I also wonder why we need this IC.
It's basicly a bunch of not gates. And for hsync and for vsync the circuit is using two not gates in a row. But two not gates in a row doesn't change anything.
Am I missing something?
Well, I'm more a programmer than an electrical engineer. So I think I'm missing something.

And which numbers are for the resistance value? I don't see any numbers with an Omega or "Ohm".
Is it 75Ohm for the pulldowns on the r, g and b lines and 175Ohm for the VCC pin on the IC?
Title: Re: VGA from Cubieboard
Post by: diogoc on November 18, 2013, 04:35:23 am
No, you can't use the 74HCT version because it is slower.
In the new versions of cubieboard you can connect directly the vsync and hsync pins, without the IC.

You only need 3 resistors of 75 ohm between the R, G and B signals to GND.
Title: Re: VGA from Cubieboard
Post by: JuSchu on November 19, 2013, 10:12:50 am
In the new versions of cubieboard
Do you mean Cubieboard 2 and Cubietruck or do you also mean newer Cubieboards from the first version?
Title: Re: VGA from Cubieboard
Post by: diogoc on November 20, 2013, 03:47:27 am
It should work too on Cubieboard A10 version 09/09
Title: Re: VGA from Cubieboard
Post by: jujiaqi on February 11, 2014, 11:29:34 pm
HI
my good test VGA & CVBS  (Androide And Linaro)

(http://digitalcontrol.persiangig.com/gallery/Test%20CVBS%20or%20VGA-01.jpg)
(http://digitalcontrol.persiangig.com/gallery/Test%20CVBS%20or%20VGA-02.jpg)
(http://digitalcontrol.persiangig.com/gallery/Test%20CVBS%20or%20VGA-03.jpg)

HDMI PIC (LINARO)
(http://digitalcontrol.persiangig.com/gallery/03.jpg)

Could you tell me  where  I can  download the android source which you use in pictures aboue, thank you very much!
Title: Re: VGA from Cubieboard
Post by: ahrovan on February 12, 2014, 02:12:51 am
http://brg.vvs.ir/2014/02/cubieboard-vgaboard/

(http://brg.vvs.ir/wp-content/uploads/2014/01/21323-286x300.jpg)
(http://brg.vvs.ir/wp-content/uploads/2014/01/34643634561-300x225.jpg)
Title: Re: VGA from Cubieboard
Post by: patwood on February 12, 2014, 10:37:20 am
That's very nice. BTW, when you play videos, do you get them on both LCD and VGA, or just one?