DLPDLCR2000EVM: proj_on_ext doesnt works as expected

Hello,

Doesn‘t anyone have an idea?

edit:

Found something in this thread:  DLP Lightcrafter 2000 EVM

Philippe Dollo wrote: "...> HOST_PRESENTZ is an active-low signal which is used by the EVM to tell whether a host processor is connected to the system, and controls whether PROJ_ON_EXT is referenced by the system...."

Now my question is:

Does this mean, that HOST_PRESENTZ has to be set to HIGH or LOW in order to "activate" the PROJ_ON_EXT Input?

I can't find anything about "HOST_PRESENTZ" in the Datasheets....


Regards
Reiner

Hello Vivek,

Thank you very much, that sounds plausible. I will test it later in the day...

But the function and relationship of these two pins is not described in any of your documents.  Also not in section 3.2 of your attached document.

regards

Reiner

Hello Vivek,

Unfortunately, it only works partially.

I now control the two pins via the Raspberry Pi with a small Python script.

First I set HOST_PRESENTZ to 0.

Directly afterwards PROJ_ON_EXT is also set to 0.

The beamer then goes off (everything is correct so far).

Now I wait for a keypress after which a video should be started.

After the keystroke I set PROJ_ON_EXT to 1 again and start the video.

The video runs (I hear the sound), but the beamer remains inactive. (If I start the video by hand on the command line, before setting PROJ_ON_EXT to 1,  it runs without problems !)

In short: if I activate the beamer once with PROJ_ON_EXT=0, I cannot reactivate it by setting PROJ_ON_EXT to 1.

Did i miss anything?

regards

Reiner