can i run standard VGA into my pico projector?

while all the graphics related traffic lately has been related to BB
to projector, can i drive stock VGA video from, say, a laptop with an
HDMI port directly into the projector? the projector box seems to
suggest that.

rday

while all the graphics related traffic lately has been related to BB
to projector, can i drive stock VGA video from, say, a laptop with an
HDMI port directly into the projector? the projector box seems to
suggest that.

Yes, the beagle does exactly that. There are 2 things to consider:

* the projector only supports 640x480@60Hz
* it has no DDC, so you'll have to manually enable the video output (OSX has a big FAIL in that category)

regards,

Koen

hmmmmm ... i just tried that. i have access to one of these:

http://www.quantumdata.com/products/882E.asp

so i switched it to generate a VGA@60Hz test pattern, and ran HDMI-out
from the video generator into the projector. the result was not
pretty. i'll try again later. thanks.

rday

Yes, the beagle does exactly that. There are 2 things to consider:

* the projector only supports 640x480@60Hz
* it has no DDC, so you'll have to manually enable the video output
(OSX has a big FAIL in that category)

DDC = Display Data Channel? In given case - Why is the patch for changing
I2C_3 from 400kHz to 100kHz then needed for the projector in case the DDC
lines aren't connected?

Best regards - Thanks for teaching me - I'm confused :slight_smile:
  Søren

We’ve seen I2C work at 400khz but not always. The I2C writes work but reads work intermitently. The slower clock speed provides margin. We are studying what modifications may be possible to the projector to improve this.

Hi Jim

We've seen I2C work at 400khz but not always. The I2C writes work but

reads work intermitently.

The slower clock speed provides margin. We are studying what

modifications may be possible

to the projector to improve this.

That part I understand, but I still don't understand the sentence:
"* it has no DDC, so you'll have to manually enable the video output" from
Koen last posting.

This indicates, that the projector doesn't have DDC at all => A change from
400kHz to 100kHz shouldn't affect anything since it isn't used/connected.
Now since you confirm, that the projector has DDC (which was my
understanding before as well) I unfortunately still don't understand Koens
sentence :slight_smile:

/Søren

Op 23 jan 2009 om 20:34 heeft Søren Steen Christensen <sorenschristensen@stofanet.d

het volgende geschreven:\

Hi Jim

We've seen I2C work at 400khz but not always. The I2C writes work
but

reads work intermitently.

The slower clock speed provides margin. We are studying what

modifications may be possible

to the projector to improve this.

That part I understand, but I still don't understand the sentence:
"* it has no DDC, so you'll have to manually enable the video
output" from
Koen last posting.

This indicates, that the projector doesn't have DDC at all => A
change from
400kHz to 100kHz shouldn't affect anything since it isn't used/
connected.
Now since you confirm, that the projector has DDC (which was my
understanding before as well) I unfortunately still don't understand
Koens
sentence :slight_smile:

It has a non-ddc i2c device on that bus.

Regards,

Koen

I2C may be of interest to a beagler to perform projector control…i.e on/off, brightness, etc…

http://focus.ti.com/pdfs/dlpdmd/PicoKitGuide.pdf

Page 15 has a list of I2c commands supported.

It has a non-ddc i2c device on that bus.

OK - Thanks - Now I got the point, except that DDC is the actual bus [1] (display-guys language for a "long distance" I2C bus between devices - Previously it could as well be another electrical protocol though :-)).

I think you mean, that the projector isn't EDID compliant [2], which is the definition of the actual data being send over the link - Correct?

This however raises two new questions:

1) In case it isn't EDID compliant a normal transmitting device won't be able to query it for information, and thereby will only work in case you can manually force it to transmit in a format which the projector understands? I think this is basically what you wrote earlier - Right?

2) What is the I2C bus used for? Proprietary I2C setup/adjusting/tuning of the projector? What can it do - Flip the image? - Invert the colors? - Etc.? I'm just curious. :slight_smile:

[1] http://en.wikipedia.org/wiki/Display_Data_Channel
[2] http://en.wikipedia.org/wiki/Extended_display_identification_data

Thanks to Jim for answering my question 2 meanwhile :slight_smile:
  Søren

i had no luck trying to drive my pico projector from the video
signal generator mentioned above. i switched the VSG to generate
simple VGA@60Hz, but all i got was a narrow smear of colour down the
middle of the image.

  i'm open to further suggestions.

rday