DLP 9000 EVM - Maximise 1bit on the fly pattern rate with HDMI/DP input

Hello User,

Welcome to the DLP Advanced Light Control section of the TI-E2E community.

For the first question: 

The rate listed in the DLPC900 User's Guide is the capability of the controller.  If you build your own board with a Displayport capable of WQXGA at 120 Hz and two DLPC900 controllers working together, then you can achieve 120 Hz video input rate.

The rate listed in the DLP LightCrafter 6500 and 9000 User's Guide is the capability of the LightCrafter evaluation kit.  The Displayport receiver used on the kit is only capable of 60 Hz. 

We are updating these two User Guides and will be putting a note to this effect in both documents to make this clear.  Thanks you for the feedback.

I am a little confused by your second question.  From the screenshot you post this appears to be achieving what you want.  Although I cannot see the remainder of the green or the blue bits the ones in the image will be shows for equal lengths of time as 1-bit images during 1/24th of the frame time.  Page 36 of the DLP LightCrafter 6500 and 9000 User's Guide explains this a little further.  The only thing that may be missing is try removing the check from the Frame Change box and then click Update LUT and run it to see if gives the result you are after.

UPDATE:  I looked again at your image and realized that you have a Frame Change between each bit - remove the Frame Change between each bit so that it will display it all in one 24-bit frame. This should work as you want.

Fizix.

Jong,

1) Video Mode:

• For Source Select there are four choices, Parallel RGB interface, internal test pattern generator, pattern images from flash memory, and solid curtain (i.e. a solid color)
• The port swap is in case the RGB input is not in the RGB order on the channels, then the correct order can be specified.
• The Pixel Data Format allows you to specify the input of the RGB data (i.e. four bits per color, 8 bits per color, etc . . .) 

All of these are discussed in § 3.5 starting on page 29 of the EVM User's Guide. --> http://www.ti.com/lit/ug/dlpu028c/dlpu028c.pdf

2) If your video is comprised of binary images you must use software to comb them into a recognizable format under Pixel Data Format.  For example your software could pack one binary pattern into each bitplane (grayscale level) of the R, G, & B of an RGB 8-8-8 video frame.

3) You simply play the constructed video from a PC to the HDMI port after setting the EVM to video pattern mode and setting each RGB bit to be re-interpreted as one binary pattern.  Details of this are in §3.2.1 starting on page 35 of the EMV User's Guide

Fizix

Jong,

I am confused by the question, "How can I synchronize the projection so that the images in each bit plane are in order?".

Each bitplane is only one image.  In the GUI it shows R 0-7, G 0-7, & B 0-7.  This is just a way of keeping track of how they are coming in.  Just think of these as indexes.  In the Pattern Design section of Video Pattern Mode you can choose the color to be displayed.  You can also specify bit depth, which consecutive bit, the exposure time for each bitplane.  But if you have syncs incoming and your total exposure time is longer than the space between syncs it will not synchronize correctly.

Fizix

Jong,

Thank you, that explanation makes it clear what you mean!  I just looked at your exposure time and realized that it is 1/2 a sec per each pattern!  At that rate you are running much slower than the input frame rate, so the effect may be somewhat unpredictable.  I originally read that as 500 µs not 500 ms.  Your effective pattern rate is only 2 Hz. Did you mean ms or µs?

What is your video input sync rate?  If it is 30 Hz then you should send the same pattern in video for 15 frames, then the next for 15 frames, etc. .. and only use one bit out of each frame (say G0).  Any thing else is a waste.  This means you can pack all 24 bits in each frame with the same bit data or all zeros except one bit (again lets say G0).  Then show that 24-bit video frame 15 times, then the next pattern the same way for 15 video frames, etc . . . .

If you meant 500 µs then your effective frame rate is near to 90 Hz (12 ms for the 24 bits plus some overhead as discussed in the user's guide).

Fizix

Jong,

When you are in the Video Pattern Mode on the Pattern Mode area under Pattern Design menu as your image shows.  This will cause the incoming stream to be divided up.  If you have 24 1-bit images in it they will show provided that your exposure time for each is short enough to fit 24 of them in the frame time.  If you are running 60 Hz then each must have an exposure time less than 1/24 of a frame time or about 694 µs.

Maybe I am nut understanding correctly.

Fizix

Jong,

The total display time can be shorter, but not longer.  If it is shorter, then there will be some dark time at the end until the next sync occurs.

Fizix