• State Resolved
  • Locked Locked
  • Replies 4 replies
  • Subscribers 30 subscribers
  • Views 1285 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.

Lightcrafter 6500 Input trigger - synchronising actual exposure of patterns with external trigger signal

Alexander Zagajewski
Prodigy 60 points
Other Parts Discussed in Thread: DLPC900

Hi,


Just a quick question regarding how the Lightcrafter 6500 GUI works with the input trigger. For my application I am using an external trigger to cycle through prestored patterns in the DMD as part of a sequence, in a highly synchronised way.

The trigger works, and when input 1 goes high, the patterns change. However, I have been wondering if it is possible to set the GUI such the the exposure of each pattern is automatically adjusted to the trigger signal and not controlled directly from the GUI? Currently, it receives an impulse, then projects a pattern for the time specified in the GUI and then goes blank until another impulse is received. Instead, we need it such that when an impulse is received a new pattern is projected, and stays projected until another impulse arrives, which advances to the next pattern and so on.


So far we have been getting around the issue by manually adjusting the exposure to match the frequency of the input trigger, but this is not optimal and takes a lot of time. Is there a quicker and better way around the issue, by somehow getting around the exposure control in the GUI?


Many thanks

Alex

  • 0
    TI__Mastermind 30600 points
    Hi Alex,

    It sounds like you don't want there to be any dark time between patterns. If that's the case, can you just set the exposure of each pattern and put no dark time? Period = exposure?

    Are you looking to have variable exposure ? Will your input trigger be changing frequency?

    Finally - in the GUI, you can select all the patterns at one time by selecting the first one, holding down shift and then selecting the last one. That will allow you to modify the exposure of every pattern at once.

    Hope this helps,
    Paul
  • 0 in reply to Paul Goedeke
    Prodigy 60 points

    Hi Paul

    Thank you for your reply. Yes - this is what we're doing so far, adjusting the exposure time to fit the external trigger frequency.  I've just been wondering if there is a way of instructing the DMD to display the pattern until the next trigger impulse is received, not displaying them for whatever the GUI control was set to. What is currently happening is that we need to set the exposure ever so lower than the input trigger period to make sure the DMD doesn't miss input triggers which is a bit of a hassle and contributes to noise.


    Alex

  • 0 in reply to Alexander Zagajewski
    TI__Mastermind 30600 points
    Alex,

    If you look at section 2.4.2.1 of the DLPC900 programmer's guide: www.ti.com/.../dlpu018b.pdf, you'll see the available triggering modes on the device.

    I don't think that the device supports what you're looking for, I'm sorry. Perhaps you'll be able to make one of the other modes work?

    Paul
  • 0 in reply to Paul Goedeke
    Prodigy 60 points
    Hi Paul,

    Thank you for your help, we've manged to find a way around it.

    Alex