DLPLCRC900DEVM: Video pattern mode does not refresh the picture display.

Hello Junfa,

Please provide a screenshot of the Parallel Port Configuration while in Video Mode.

Also please see if driving the HDMI with a different computer (make sure it is not the identical video GPU) to see if if works with another system.

Fizix

Hello Fizix ,

The configuration at 2716*1600 30Hz and 2716*1600 15Hz is shown in the following figure:

I used three other different computers (different video GPU), and the parallel port configuration while in video mode (at 2716*1600 30Hz) was the same, and the result of using it in Video Pattern Mode was similar, that is, the pattern could not be refreshed.

Hello, Ti team.

I have some other questions to explain. Because no relevant instructions were found or some instructions may be misunderstood.

1.
According to the DLP9C00 manual, A120-Hz 24-bit frame is composed of three colors (red, green and blue) with each color equally divided in the 120-Hz frame rate. Thus, each color has a2.78-ms time slot allocated.

Then my understanding is, does each color has a 2.78-ms time complete 8-bit depth display? But in the following table, the 8-bit depth display of DLP670S needs 4046us, why?

2.
According to the DLP9C00 manual, a single video frame is composed of a series of bitplanes.
For a 24-bit RGB frame image inputted to the DLPC900 controller, the DLPC900 controller creates 24 bit-planes, stores them in internal embedded DRAM, and sends them to the DMD, one bit plane at a time。

How to understand bit planes? How to understand these 24 pictures in G0-B23 (in Video Pattern Mode)? Are these 24 pictures defined by a frame of video streaming or by DLPC900 controller?

If it is the former, that is, B0-B23, these 24 pictures are defined by a frame of video streaming, what format or software will I use to package a frame of video streaming, and each picture from B0-B23 should be 1bit, that is, black or white.

As shown below, a frame of video streaming contains multiple pictures. P1 can be R0 or R0-R5, right?

In the latter case, DLPC900 controller will receive each frame image of HDMI video streaming (based on The VSYNC signal), and then divide it into 24 bit-planes, that is, these 24 pictures corresponding to G0-B23.

3.
In the Video Pattern Mode option, if Depth selects 1 and Start Bit selects G0, DMD will display G0 in Exposure time with binary pulse-width modulation, and this image is black or white.
If Depth selects 2 and Start Bit selects G0, DMD with binary pulse-width modulation displays G0+G1 in Exposure time, right?

Hello Fizix ,

Ok, I understand, thank you!
But my main problem is how to solve the problem that it can't refresh the picture display in Video Pattern Mode. This project is urgent, please help me analyze and give a solution.
The pictures we use need to be refreshed in real time and are not repeated. We will not consider the Pre-stored Pattern lode and the Pattern 0n-The-Fly Mode because the speed of switching pictures is too slow.

Hello again Junfa,

As a test, please try setting the exposure time to 33000us (from 4046us) and the dark time to 0us (from 27000us).  Update the LUT and run.  Does it display and refresh the frames. and is the Video Running checkbox on?

Let me know if this changes the behavior.  If not we will need to dig deeper.  It is not necessary to add dark time if you use the "clear".

Also be sure that Trigger in 1 and Trigger in 2 do not have any signal on them.  I recommend holding them low with a pulldown resistor. 5-10KOhm would be fine.  

Fizix

Hello Fizix,

Okay, thank you for discussing this issue. I have ensured that Trigger in 1 and Trigger in 2 are held low with a pulldown resistor of 7KOhm.

My power-on sequence is simple. I connect the HDMI cable first, then power on the device, which defaults to the Video Mode. After 5 seconds, the LED turns on.
The HDMI source is 2716*1600@30Hz, and the display is normal at this point, with the Video Running and Locked to External Source checkboxes both on.
When I switch to the Video Pattern Mode, the Video Running checkbox turns off and the Locked to External Source checkbox remains on; then I add a pattern, update the LUT, and run. Only one picture is displayed (seems to be the one loaded by DLPC900 before switching to the Video Pattern Mode), and there is no refresh of the frames. The status is as follows:

Repeating this process yields results that are basically the same. However, there was one instance where the Video Running checkbox and Locked to External Source checkbox remained on, but only a white picture was displayed, without refresh of the frames.
At this point, I stopped or did not stop the Sequencer Running, then switched the HDMI source to 2716*1600@15Hz, with the Video Running checkbox on and the Locked to External Source checkbox off. Then I updated the LUT and ran, and pictures were displayed, and the frames were refreshed, with the status as follows:

If the device powers on and enters the Video Mode (2716*1600@30Hz), switches to the Video Pattern Mode, and then switches the HDMI source to 2716*1600@15Hz, the results are the same as above.
If the device powers on and enters the Video Mode (2716*1600@15Hz), switches to the Video Pattern Mode, and then switches the HDMI source to 2716*1600@30Hz. the Video Running checkbox on and the Locked to External Source checkbox on. Then update the LUT and run. There is a display of the picture and refresh of the frames, but the picture display is incorrect (regardless of 1 depth or 8 depth), the status is as follows:

All the above tests, I used 6.1.0 (I want to know why it is currently discontinued) and 6.0.0 firmware, the result is the same. I used GTX 1650, RTX 3060, and RTX 3050 graphics cards, the result is also similar.

Hello again Junfa,

When a new version comes out (6.2.0) the previous version shows as "discontinued" to encourage people to use the latest version.

NOTE:  You must always stop the current solution from running before "updating the Video Pattern Sequence and then start it running afterward.

When you tried running at 30 HZ with the timings I suggested, does it still show the video not running?

Are you able to look at the sync signals into the controllers at TP14 and TP33 on the controller board.  Do they look correct for Vsync?

Fizix

Hi Fizix,

OK, here's the reply:

1. Yes, I tested version 6.2.0 today, but the result is a little different, that is, there is no picture displayed when switching to the Video Pattern Mode at 15hz.

2. I know that I need to stop running. I am just testing, and I will test both stopping and not stopping.

3. Yes, as the previous reply, when I use 2716*1600@30hz, in Video Mode, the video running, and then switch to the Video Pattern Mode, the video not running.

4. I can test the sync signals, as shown below, there is synchronization. Whether I use Video Mode or Video Pattern Mode, the two sync signals are always there. When I switch to 15hz, the sync signal also exists.

I suspect that this problem is a software bug, can you help to verify whether there is the same problem?
If possible, please give me a software version that fixes this bug for testing.
This was a great help to my project progress, thank you very much!

Hello Junfa,

Thank you for confirming that the Vsyncs are present.  That is good news.

I would like to try this same setup in our lab.  What are you using for video input?

Fizix

Hi Fizix,
Ok, thanks for the support. As mentioned earlier, I'm using a laptop HDMI output with a graphics card model either GTX 1650 or RTX 3050 with a resolution of 2716*1600@30hZ or 15hZ.

Junfa,

Sorry I was not clear.  What content are you sending to the DMD?   In other words how do you know that it is updating?

Fizix

Hi Fizix,

Ok, I'm using the extended mode of the multi-display Settings in the notebook, so the DMD will display the second screen content of the notebook. I opened a picture on the second screen and displayed it in full screen. There are several pictures in this folder. When displaying it in full screen, I switched the picture by left and right keys to observe whether the image of DMD has changed

Hello again Junfa,

I have sent you a friend request, to see if I can connect more directly to help you get going faster.

Fizix

Hi Fizix,

OK.