panda 4500

Hello Sanjeev,

Thanks for your response.I have managed to display patterns through video port,but I still have some questions.

1.To display patterns in white,I set  G0:G7  to RED,R0:R7 to GREEN and B0:B7 to BLUE.In this case,the white can be displayed,but other mixed color like Cyan is not normal and the pattern is in mess.Is it  the normal phenomenon?What can I do to make it better?

2.As I mentioned before,I want to have a bigger memory to store patterns. Now  we use video port,but we still need to make patterns into video and store it .At first ,we choose pandaborad 4500,but we cannot buy it in China.We change to pandaboard ES .As I know from the pdf ,it can work out. However ,I want to make sure if it can coordinate with DLP 4500 well because we don't want to buy it wrong.Can you give me the affirmatory answer?

Best regards!

Jiong

Hello Jiong,

#1. You are talking about two things, first, color not normal and secondly, pattern is in mess.

For the first, there is simple way to get the colors proper, use InputDataChannelSwap command USB-0x1A37 I2C-0x04, select different options to set the color order in which you want.

For the second, pattern is in mess, you should be very careful in which order the data is read in the system, DataChannelSwap provide more details about this, default ABC=>BCA. Then the other factor is Pattern Display LUT.

#2. Yes, PandaBoard ES can also work with LightCrafter4500, 

Regards,

Sanjeev

Hello Sanjeev,

#1.In solution,I set DEFAULT.PORTCONFIG.ABC_MUX  to 0*0---ABC=>ABC.It can show red,green and blue correctly,but the mixed color is wrong.

#2. From the pdf,I found that pandaboard software need to obtain the Ubuntu® kernel from the repository.Can I use win7?

#3.We hope to download the video into pandaboard through Ethernet.The video can be stored in the sdram.When we want to display the patterns through video port,the pandaboard can transmit the video into DLP4500 to project.It also use a output trigger to synchronize a camera.Can it work out in your opinion?

Best regard 

Jiong

Hello Jiong,

#1. Can you please explain what do you mean by mixed colors wrong. After setting ABC_MUX setting, do one more thing, select mixed color say CYAN = BLUE + GREEN (ON), now switch ABC_MUX settings step by step, when it displays right color then it has to be the proper settings for the data you are sending.

#2. No. The PandaBoard image has to be built on Linux system like Ubunutu OS on a PC.

#3. Okey, your plan is to communicate with Pandaboard via Ethernet port, use this link to transfer the pattern data, then Pandabaord display data on its display buffer. Yes, it is possible, it is very impt that you understand the delay in transferring the pattern data over Ethernet. It will be slow, if it speed is not a problem for you then it should work.

Enabling Ethernet connection on PandaBoard, sending pattern data over Ethernet, etc needs to be developed on your own.

Regards,

Sanjeev

Hello Sanjeev

The first picture is projected by DLP4500(ignore the 'H' which was sticked by others).The second is original picture from PC.DLP4500 was working from video port of pattern sequence.

You can find that in the projected picture the red is normal,but other color is in mess.But in video mode,it is fine.

Best  regards

Jiong

Hello Jiong,

It looks to me the second picture is not correct, in the GUI it looks like you are in Pattern Sequence Mode, refer to "Operating Mode" section. 

In the first picture the image is messed up because of your Pattern Sequence mode configuration. 

Please provide step-by-step procedure on what you did to get the messed up image. Also let us know what are you trying to configure.

Regards,

Sanjeev

Hello Sanjeev,

#1. Yes, it was in pattern sequence mode  through video port. I set  G0:G7  to RED,R0:R7 to GREEN and B0:B7 to BLUE.Internal trigger and exposure time are 500us. Is it  the normal phenomenon as  I set?We need to use 1-bit pattern.

#2.What do you mean by saying that the second picture is not correct? It is the screen of the PC which connected to the DLP4500.I use the graphic card to send video to video port. So ,the PC and the picture projected are synchronized.

#3.Recently,i have found that when the Vsync triggered the DLP4500 ,then the patterns were projected without the influence of   Vsync.I tested the trigger_out_1.The pulse is 20us.The interval is set to 500us.Every 24 pulses is a period.After a period,there is a longer interval aroud 250us.So ,the period is 500*24+250=12250us.The frame rate is 60hz. The projected period is not synchronized with the frame rate.If I play a video at 60hz,the camera triggered by trigger_out_1 will capture the picture with overlapping,When I set the internal trigger and exposure time to 694us,the period is 16.7ms.I don't understamd why the period of  trigger_out_1 is less than 16667us when the interval is set to 500us.Is it because that the DLPC350 stores two 24-bit frames in its internal memory buffer?When the first pattern is displayed ,the second is stored and doesn't need the Vsync signal.Am i right?

Best regards

Jiong

Hello Jiong,

#1. I think you are confused the RGB input data with Pattern color information selection. Based on your color selection setting I think it is expected behavior.

In the Pattern Mode, the incoming RGB24 bit data can be selected with any color you are interested it is nothing do with R7:0 or G7:0 or B7:0. For example Red bit#4, you can set to any color Red, Green, Blue, Cyan, Magenta or Yellow or white. 

Please send me details what you want to display the RGB24bit data in Pattern Mode? 

#2. What i meant is that in the GUI, under the Mode Selection option, i see you have selected Mode - Pattern Sequence and video displayed like a regular video. This is not correct. In Pattern Sequence mode you will not see video like this.

#3. 

500*24+250=12250us

Last or + 250us at the end is because you have selected clear the DMD i.e., run black pattern at end of displaying patterns.

I don't understamd why the period of  trigger_out_1 is less than 16667us when the interval is set to 500us.Is it because that the DLPC350 stores two 24-bit frames in its internal memory buffer?

[Sanjeev] Your source input is from external RGB24bit video port, this maps to 'Trigger Mode 0" refer to DLPC350 Programmer's  Guide section 2.4.3.2 Trigger Controls, the behavior fixed as described in the document. Since you have set the pattern exposure as 500us, on the trigger_out_1, it will show pattern exposure period, there are 24 patterns, so you will see 24 exposure pulses on this signals. This period is nothing to do with frame-period which 16667us in your case.

Programmer Guide Figure 2-9. Trigger Mode 0 Timing Diagram Example documents this.

The incoming VYSNC is just used as trigger input synchronization signal, so on vsync, it runs as per Pattern Sequence LUT setting, in your case you have selected to display all the 24 bit patterns with 500us exposure from the VSYNC reference. 

When the first pattern is displayed ,the second is stored and doesn't need the Vsync signal.Am i right?

[Sanjeev] This is correct.

Regards,

Sanjeev

Hello Sanjeev,

#1. We want to make colorful image reconstruction.But at first monochrome image is enough.What I did before is just a try.

#2.You said the video shouldn't be like that. Then, what should it be ?

    My laptop cannot set to 912*1140,so I connected it to another display via VGA port and the framerate is 60hz. The DLP4500 is connected to my laptop via HDMI port. The HDMI is first changed to DVI-D  and then changed to mini HDMI. Finally, it projects like that,as you said,like a regular video.Where is wrong?

#3.I didn't select clear the DMD.The trigger internal and the pattern exposure are the same .Then why 250us

appears?

#4. Since the vsync is not need , when I play a video at 60hz. Each frame is 16667us,when the pattern exposure is 500us,the pictures taken by the synchronized camera will not be what  I want to take  as it will be faster than the frames.Is the way to solve this situation to change the pattern exposure to 694us?

Best Regards

Jiong

Hello Jiong,

#1. OK

#2. My point was - as compared to how the PC monitor is shown 'Video Mode" vs 'Pattern Mode" differs significantly. Your GUI snapshot showing you are in 'Pattern Mode' but the output image looks like as if it is "Video Mode" i.e., all colors like a regular output.

#3. I think we are missing something important, can you explain via timing diagram? Show the VSYNC and with reference to VYSNC how the trigger_out_1 is appearing, and where is 250us period you have concern?

#4. Playing a video is nothing to do with VSYNC, irrespective of you play video or not, the video data is always available on digital interface to the EVM, when you play video in full screen mode on the LightCrafter 4500 port, each output video frame written. Sorry I am not able to understand what you are planning to say here...

Regards,

Sanjeev