Beagle Vga board from beagleboardtoys in Sydney

Hi all,

Is it possible to buy "Beagle Vga board" from www.beagleboardtoys.com
in Sydney, Australia? There is no contact details on website and I
can't add Australian address at checkout. Thanks.

Cheers,
Max.

As a note of advise, if it is for the -xM it won’t work, it has some issues that produce wrong gamma

Lioric

Hi Lioric,

Thanks for your response. It seems that you've done a lot of work
trying to get VGA output from BB-xM. Could you please share your
results with us? Are there any not very expensive "DVI-D -> VGA"
adapters which were tested with BB-xM? Thanks in advance.

Cheers,
Max.

I would be really appreciate if anyone tell me if I can use this DVI-D
-> VGA adapter with BB-xM:

http://www.fit-pc.com/web/fit-pc2/accessories/fit-vga/

Is it OK if this adapter doesn't have an external power adapter? Can
it be powered from DVI port on BB-xM? Thanks.

Cheers,
Max.

It might. I would need to understand more on how it works. They may be taking the DVID signal, decompressing it and then driving an A/D. But there isn’t enough information to know for sure. But it sounds promising. I would say give it a try and let us know if it works. The pricing looks very good for such a function.

Gerald

2011/2/23 Ира Галемина <irina.galemina@gmail.com>

Considering the price for this adapter is rather high ($40) it can be used with BB, but you need to try :slight_smile:
Another pros is the phrase “fit-VGA can be used with other computers having only digital display interface”. “Only digital” is the only one that BB has

Yes, if possible, test it and report

Im currently testing several other “active” converters and will post the results, as we definitely need a converter for those who need that option

The only thing that worries me about the “fit-pc” converter is that is is driven using the available dvi current (and not uses its own supply, as the ones that Im testing), and from previous reports on a similar converter (the hd furry-something) it seems that this type won’t work (even more with the -xM board that seems to have tighter current specs)

Lioric

Yes, I have tested several, and Im in the process of testing some more, as soon as I identify a cost sensible, working solution I will provide the results

Lioric

Ok, I received my fit-VGA converter. And of course it has an issue. :slight_smile:
I can see 1280x1024 picture on my monitor for a couple of seconds
(which is good, colors are OK) and after that monitor goes to the
power saving mode (which is bad). I'm not surprised as I read about
this issue before:

http://www.fit-pc2.com/wiki/index.php?title=Connecting_fit-VGA_to_a_computer_other_than_fit-PC2

So here are possible solutions:

- Disable DDC / EDID in BIOS (if supported).
- Disable DDC / EDID in display driver (if supported).
- Disable DDC / EDID in display (if supported).
- Uninstall display driver in order to use default VESA drivers that
do no query DDC.

How can I disable DDC/EDID in linux kernel drivers (2.6.32)? Or how
can I use VESA driver (which is enabled only for x86 platform)? Or can
I just remove DDC/EDID pins from the monitor VGA connector? Thanks.

Cheers,
Max.

Update: fit-VGA works fine with parameter "omapfb.mode=dvi:
800x600MR-24@60" so I'm happy enough. At higher resolutions (1024x768
and 1280x1024) monitor IBM ThinkVision L174 goes to the suspend mode
after some period of time (10..60 seconds) and i can see some weird
artifacts on the picture. There are no any messages in "/var/log/
messages" and I tried to compile kernel with different drivers and
even commented out all the code responsible for suspending displays,
so probably my monitor just can't recognize video signal from fit-VGA
with resolutions higher than 800x600.

P.S. I'm using QT application with output to the framebuffer (without
X window system).

Cheers,
Max.

DDC system is disabled by default in Linux kernel for BB.

2011/2/26 Max Galemin <maksim.galemin@gmail.com>

that implies there is ddc support for beagle, which there isn’t

That doesn’t seems to be a DCC issue, most probably its a timings issue

If the display is only powered for a couple of seconds, then that might shown that u-boot timings are correct, but as soon as the kernel display driver kicks in, the adapter don’t support those timings

Just see what timings your monitor uses for each of the resolutions you want to use by connecting your monitor to a dev machine, and then use fbset or cat directly to the dss display0 timings file (in a boot script)

How can I disable DDC/EDID in linux kernel drivers (2.6.32)?

As far as I know bb doesn’t use DDC in the current kernel

can I use VESA driver (which is enabled only for x86 platform)?

This is embedded world, were almost all (if not all) is specialized, there are not VESA drivers for bb

I just remove DDC/EDID pins from the monitor VGA connector? Thanks.

Sure, just purchase a cheap VGA cable extension and remove pins 12 and 15

But then again bb kernel dont uses this data, but maybe the fit-pc adapter does(?)

Lioric

Guys, did you read my the very last message? There is nothing to do
with DDC/EDID because fit-VGA works at 800x600. It's a probably issue
with my monitor.

Cheers,
Max.

Hi guys,

I found the exact reason for the issue with power saving mode:

http://maxgalemin.blogspot.com/2011/03/dvi-d-to-vga-converter-for-beagleboard.html

Cheers,
Max.

That sounds great, now we have at least a confirmed option for VGA

Yet, sadly it still requires a mod

Will post my findings on other options later

Lioric