Waiting to know if BBB supports pico projectors over its HDMI port.
I’m curious and eager, since angstrom distributions for Beagle Bone did not support Picos ( I had a sleeve for Beagle Bone that had a HDMI port ).
Please let me know ASAP since I’m planning to order one.
Thanks.
Aravind.M
What is the resolution of the Pico projector you have in mind? Typically the resolution is pretty poor. You can look at the resolutions supported as listed in the manual. I don’t recall if the Pico supports EDID. If it does it should work OK. Otherwise you may have to manually change the boot parameters to go to the desired resolution.
Gerald
Gerald,
Here are the details of the pico I have :
Technical Specifications
Actually this did not work with BEaglebone with HDMI cape ( since the supporting code was not there in the angstrom distribution ).
Please let me know if changing the display parameters in the env file would suffice to make it work as far as BBB is concerned .
Regards,
aravind.
if this is the projector you're talking about:
http://www.digikey.com/product-detail/en/2510094-0001/296-23836-ND/1960741
i have one around here somewhere and can test this as soon as i find
it. if memory serves, the projector itself has a *mini* HDMI interface
so i'd have to go out and get a mini-micro HDMI cable.
that unit is discontinued, you noticed that, right?
rday
Yes, it is the same thing and it is discontinued.
But mine is live as yet and would want to use it atleast with the BBB. Beagle bone did not work with it.
So would like to atleast put to use it now.
Please let me know once you test it. Then I will go ahead and order a BBB.
ok, i found it at the back of a drawer, it's that same model, and
yes it has a mini-HDMI input so i'll need to pop by the computer store
later today to pick up a cable or adapter. in the meantime, feel free
to tell me *exactly* the set of steps to properly test this. i've got
one BBB running the original build, and the other the latest
BBB-eMMC-flasher-2013.05.08.
rday
Thank you.
This should help you http://www.ti.com/lit/ug/dlpu003a/dlpu003a.pdf
And ideally if connected , you should be able to see the bootup screen and the terminal being projected
-Aravind
You cannot change the display parameters in the uENV.txt file. It will not work. You have to cange it in th eboot parameter file.
480x320 is really low. I don;t know that the HDMI chip we use can get that low. What we had before was a DVI-D chip.
Gerald
this page:
http://hipstercircuits.com/my-kingdom-for-a-4-3-hdmi-compatible-lcd/
suggests that 480x320 isn't going to work:
"But even if the DVI receiver chip was able to receive at a low
resolution, the TDA19988 chip that converts the signal from 16 bit
parallel RGB to Transition-Minimized Differential Signalling (TMDS)
on the BBB is unable to send at low resolutions. The lowest resolution
it can send is VGA (640×480) according to it’s datasheet, ..."
rday
Just for the record. The HDMI Cape uses the same chip as the BeagleBone Black.
Gerald
So, is the verdict going to be, pico projectors with 480x320 resolution is not going to work on BBB (with or without cape )?.
-Aravind
It will NOT work
Gerald
yes, the pico accepts 640x480 which is the lowest and mandatory HDMI mode
you're right, i should have remembered that. so if i can just lay
hands on a micro <-> mini HDMI cable, will the current image
auto-detect via EDID the correct res and simply work? still can't test
it as i've yet to pick up the cable.
rday
got the cable, plugged BBB into pico projector ... nothing. pico is
still displaying the splash "TI DLP" screen. is there a timing/order
issue? should i plug in the pico before or after boot?
i'm ssh'ed into the BBB right now, is there an EDID detect utility?
open to suggestions. oh, and i'm running the 2013.05.08 image, is that
even trying to display?
rday
That image tries to display on most monitors and does indeed succeed.I am looking at one right now. I also just saw several hundred boards in production pass testing as well.
The display needs to be plugged in to read the EDID. Power up the board and connect the projector and then reset the board to make sure the projector is ready to give EDID, assuming it can, and that the board can then read it…
Gerald
assuming i'm reading you correctly, i:
* powered off BBB
* disconnected HDMI
* powered BBB back on, waited for full boot
* ssh'ed in just to verify proper boot
* connected pico projector
* pressed "reset" button on BBB
no luck -- still standard "TI DLP" splash image.
rday
Are you sure the projector has EDID? Back in the day when I worked with those guys on that I don’t recall that ever being discussed.We did not have EDID support in SW on the -xM.
If nothing is found out on the HDMI by reading HDMI, I think the SW assumes nothing is there. Sounds like we need a way to force the display to turn on. Can you get it working on a regular monitor and then just move the cable to the projector?
Gerald
it's entirely possible there isn't -- i'll check on that later this
evening or tomorrow. ubuntu has a "read-edid" package i've used
before.
rday
The original pico projectors lack the edid register bits. After a few
months, all of them still on the shelves had been recalled to be
'reworked' and the edid register bits had been added to them. These
reworked/later units had the big #2 revision sticker on top of side of
the case...
Regards,