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DLP350 Lightcrafter 4500 Firmware bug causing intermittent crashing when switching between pattern mode and video mode.

We have created a custom IMG for the lightcrafter 4500. 

The image instructs the projector to boot into pattern mode.   This works if the project is not connected to a PC via HDMI, however if a PC is connected via HDMI, the presence of the HDMI seems to force the projector into video mode as opposted to pattern mode.

If we boot the projector before turning on the PC it will boot into pattern mode and stay in that mode when the PC boots up.

How can we stop the PC from changing the mode to video mode?

Thanks

Gavin

  • Hi Gavin,

    Welcome to the E2E forum and thank you for your interest in DLP technology!

    To be sure that we're starting on the right page, are you using a DLPLCR4500EVM or a custom board?

    Regards,

    Austin

  • We are using 3 different boards , including that one from Wintec, but the results are the same on each of them so it must be the firmware as it is common to all 3.

    Regards

    Gavin

  • Gavin,

    To be clear, these boards are all unique designs?

    The reasoning behind my question is that if these boards are DLPLCR4500EVMs, then they are behaving as one would expect. The EVMs will automatically switch to external video when data is detected at the HDMI port due to a micro-controller on the board. In such a case, we may be able to alter the code to avoid this behavior. However, if these are custom boards it may be in your best interest to speak with the designer and firmware author.

    Regards,

    Austin

  • Hi, this issues is actually a follow up to an issue we raised last week   ( support/dlp/f/94/t/968244 )

    If you have a read of that one it will provide some context.   In the original issue we found a bug in the base ROM for the lightcrafter 4500 that causes the projector to crash after repeatedly switching from pattern mode to video mode. ( we supplied a sample program for you to run with the source to recreate the issue )

    In order to find a workaround for the bug until it is fixed, we made an alternative rom using our own INI file, which instead of starting the projector in video mode and then issuing USB commands to switch to external pattern mode, we would simply ask the projector to boot up into external pattern mode.

    When you say it acting as designed I think you are assuming that if a HDMI signal is detected, the controller believes the data structure will for normal video in 24bit color, however, we are using it to stream pattern modes over hdmi ( not internal pattern modes from onboard ram )

    So yes, we wish to use HDMI, but we want it to remain in pattern mode over HDMI and not desktop video mode.

    Thanks

     

  • Hello Gavin,

    One of our team member will get back in couple of days on this issue.

    regards,

    Vivek

  • Hello Gavin,

    Can you read the current mode of the Lightcrafter 4500 before sending the video? When controller is configured in external video mode, as soon as it seen vsync is start processing. In External Streaming mode one of the precondition is for the front-end to detect the video source properly it does this in video mode only. 

    One other way is to stream blank video in video mode and then switch to external streaming when th source is locked and controller is ready to display the data.

    If you have access to DLPC530 UART0 TX line you can look read and send us the UART debug log, for this you can UART TTL 3.3 to USB converter cable and tap connect the RX line to TX line from controller and any GND point.

    Regards,

    Sanjeev