• State
  • Locked Locked
  • Replies 8 replies
  • Subscribers 28 subscribers
  • Views 780 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DLPLCR4500EVM: 120 Hz Pattern Sequence Mode Issues

Jonathan Trisnadi
Prodigy 100 points
Part Number: DLPLCR4500EVM

Hello,

I am interested in using the DLPLCR4500EVM in Pattern Sequence Mode in order to output 24-bit images at 120 Hz. Specifically, I want to use a pattern of 24 1-bit images so that a binary-image framerate of 24*120 Hz = 2.88 kHz can be achieved.

I have set up the pattern using Hirak's suggested .ini file found in this thread and take measurements of the DMD output using a photodiode connected to an oscilloscope. My PC recognizes the 4500EVM as a projector/monitor and sets the refresh rate to 60 Hz. Under these settings, the pattern seems to be working flawlessly -- I am able to play binary images at 24*60 Hz = 1.44 kHz when I set the exposure time to 694 microseconds. I can also adjust the exposure time to e.g. 347 microseconds (2.88 kHz) and see that the DMD is able to keep up, but it spends half the time waiting for the next 60 Hz trigger.

Screenshot of GUI (pattern is R0 R1 R2 R3 R4 R5 R6 R7 G0 G1 G2 G3 G4 G5 G6 G7 B0 B1 B2 B3 B4 B5 B6 B7):

Alternating on and off 1.44 kHz (694 us exposure, 60 Hz refresh rate):

Alternating on and off (347 us exposure, 60 Hz refresh rate):

Main Problem

The issue arises when I try to go to 120 Hz. I am using an Nvidia GTX 745 on a Windows 7 PC. This video card has a dual-link DVI-D output which I connect to the HDMI port on the 4500EVM. I make a custom resolution using the Nvidia control panel at 912 x 1140 @ 120 Hz. What I observe is that the DMD outputs an on pulse (width 347 microseconds) every 2.78 ms (which corresponds to 1 second divided by 120 divided by 3). Furthermore, this output does not change depending on the input image i.e. it's unresponsive. I can attempt to show alternating B&W, all white (always on), all black (always off), but the result is always the same.

Output at 120 Hz refresh rate (always looks like this no matter the input pattern):

May I ask you guys about the details of your setup and how you get 120 Hz refresh rate working in Pattern Sequence? What cable do you use, what kind of video card, what is the video source, do you need a custom resolution, etc. I'm particularly interested in the cable you use, since as I understand, a DVI-D dual link to HDMI adapter will only send a single link signal, which can possibly limit the refresh rate. 

Thanks for the assistance,

Jon

  • 0
    TI__Genius 12785 points

    Hello Jon,

    Welcome back to the forum!

    There are a few different setups that we use. One successful use has been an Intel UHD Graphics 620 GPU on a Windows 10 machine via an HDMI to HDMI cable.

    These tests are performed by simply by using the EVM as an extension of the computer's display, placing any desired test pattern into the frame and adjusting the refresh rate within the Window's advanced display settings.

    You may want to attempt an HDMI to HDMI cable to avoid the potential frame rate limiting if this is possible.

    Regards,
    Austin

  • 0 in reply to Austin Snyder
    Prodigy 100 points

    Hi Austin,

    Thanks for the quick reply. I tried HDMI to HDMI and got the same result. If I try using Windows Advanced Display settings to change the refresh rate (rather than Nvidia control panel), all I see is a blank drop-down menu:

    I tried HDMI to HDMI on a second PC (with Intel HD 520 graphics), and the Advanced display settings look identical.

    Does your device also show up as 'Generic PnP Monitor'? It is apparently running on Microsoft drivers from 2006 -- maybe needs an update?

    Btw, do you know if the HDMI version is important (e.g. HDMI 1.4 vs 2.1, etc)?

  • 0 in reply to Jonathan Trisnadi
    TI__Genius 12785 points

    Hello Jon,

    Yes, it appears in Device Manager as 'Generic PnP Monitor.'

    These are the screens we use to set the refresh rate. Try updating the drivers to see if this corrects the issue.

    Regards,

    Austin

  • 0 in reply to Austin Snyder
    Prodigy 100 points

    It seems Windows has determined that those 2006 drivers are the up-to-date ones. I am going to try getting my hands on a different PC or video card to test with and will update you when I can. Have you ever encountered this issue with the refresh rate drop-down menu being blank?

    Also, if there are more examples of video cards that have been successfully tested 120 Hz, it would be very helpful to know the models.

    Any other suggestions would be appreciated, thanks.

  • 0 in reply to Jonathan Trisnadi
    TI__Genius 12785 points

    Hi Jonathan,

    I have not encountered the issue with a blank refresh rate menu. Even if only one option is possible, the single option will appear.

    You may also consider attempting this as an admin. It may be that you are restricted by permissions.

    Generally speaking, I believe this to be a front-end issue. Please let us know if there is any further help we might provide to support the EVM.

    Kind regards,

    Austin

  • 0 in reply to Austin Snyder
    Prodigy 100 points

    Hi Austin,

    I managed to get my hands on a PC with Windows 10 and Intel UHD 620, and I'm still unable to set the 120 Hz. See screenshots below. What is the process for enabling 120 Hz? Every computer I've tried, it doesn't show a 120 Hz refresh rate by default, so there must be some way to enable it. Do you have an image of what your drop-down menu looks like?

    Image of Windows advanced display settings:

    I try to set a custom resolution and refresh rate in the Intel graphics settings, but it isn't allowed (I also tried using all the timing standards):

    Intel graphics settings only showing 59 Hz and 60 Hz:

    It'd be very helpful to see screenshots of your system, to make sure we're talking about the same settings, etc. One additional note: I've tried two different HDMI cables, so I don't think the cable is the issue. Thanks again for the help.

    Best,

    Jon

  • 0 in reply to Jonathan Trisnadi
    TI__Genius 12785 points

    Jon,

    Please find my frame screen shot below:

    Keep in mind that this frame rates are in relation to my monitor as I do not have access to an EVM at the moment. The frame rates will differ from display to display. No special settings were configured for this display or for the EVMs.

    Regards,

    Austin

  • 0 in reply to Austin Snyder
    TI__Genius 12785 points

    Hello Jon,

    I believe we have done what is possible on our side. You may want to continue probing the possibilities of configuring the video input on the front end.

    For now I will be closing this thread. Please let us know if you have any further issues regarding the EVM.

    Kindly,
    Austin