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DLP4710EVM-LC: Disable and disconnet light engine

Part Number: DLP4710EVM-LC
Other Parts Discussed in Thread: DLPC3479, DLPC3470, DLPC3478

Hi Experts,

We are working on DLP4710EVM-LC and want to disable and remove the light engine. We can easily find the RGB enable command (0x52) in section 4.2.4 of the document (https://www.ti.com/lit/ug/dlpu074a/dlpu074a.pdf) but we are looking for a procedure to disable completely the light engine in firmware (to avoid the issue with DLP startup) and then remove it from DLP.

Hope for some guidance on this problem.

Thank you

Mumtaz

Researcher

University of Glasgow

  • Mumtaz,

    Have you tried using the Flash Batch Update feature on the DLP Light Control GUI? A similar discussion was had on this topic here:

    https://e2e.ti.com/support/dlp/f/dlp-products-forum/891954/dlp3010evm-lc-how-to-set-all-the-led-disabled-when-booting-up?ReplyFilter=Answers&ReplySortBy=Answers&ReplySortOrder=Descending

    I hope this helps.

    Regards,

    Philippe Dollo

  • Hi Philippe,

    Thanks for forwarding the helpful link.

    After using the DLP GUI feature of the flash batch update on the original firmware file (dlpc3479_fw_8.1.0.img), can we remove the light engine from DLP? The shared link provides a solution about disabling LEDs on startup but in our setup LED will not be connected.

    Hope for guidance on this problem

    Thank you

    Mumtaz

  • Hello Mumtaz,

    The firmware will check for LED connection at power to prevent damage to Power Management IC. You can add dummy load in the LED connection line and disconnect the LEDs to the engine. 

    This will let the firmware boot up with out LEDs from optical engine connected.

    regards,

    Vivek

  • Hi Vivek, 

    That seems logical. I will try to work on this with the consideration of power management IC, and ask you if any information needed.

    Thank you

    Mumtaz

  • Mumtaz,

    Let us know if you need any additional information.

    Regards,

    Mayank

  • Hi Mayank,

    We are working on the setup of disabled LEDs (updated the DLP firmware with the batch file) and removed the light engine from DLP. In this setup, we are using DMD with only electronic boards. On power-up, the DLP GUI communicating through USB and showing "EVM Status: Connected and Powered Off". Also, the only thing we can do through GUI is to update the firmware. We checked the DMD holder and its connections with the electronic boards but the problem is not solved.

    Before moving to dismantle DLP (above setup), we successfully checked the DLP with modified firmware (same as above stated) and remove RGB connectors between the board and light engine. We successfully checked the DLP response to different GET commands from GUI.

     I hope for some help in solving the above issue (also snapshot uploaded).

    Thank you

    Mumtaz

  • Mumtaz,

    The closest you can get to this is a Red-Only LED firmware available on the Firmware Selector tool. It isn't possible to run the system with a firmware build that has zero LEDs whatsoever. You will still need at least the one LED load for the system to boot.

    https://software-dl.ti.com/dlp/pico-fw-selector/ 

    This firmware build is available on the DLPC3470, DLPC3478, and DLPC3479. 

    I hope this helps.
    Regards,

    Philippe Dollo

  • Hi Philippe,

    We just checked the DLP with different firmwares (suggested by TI of red LED only, and original firmware). Also, all fans and LEDs are reconnected and powered from DLP main electronic board. The status on GUI is showing "Error while trying to gain access to the I2C bus" and "EVM Status: Connected, Powered Off" (same as before). But with any firmware configuration, we can update the DLP firmware through USB.


    Status of the mainboard LEDs:

    LEDs D43 and D57 light up when the SW28 slide switch moved to the ON position.
    LEDs D36, D33, and D34  are always OFF when SW21 push-button pressed. With SW21, only LED D56 flash two times, and LED D57 status change to OFF and then again ON.

    Hope for some guidance on this issue.


    Thank you
    Mumtaz

  • Mumtaz,

    Did you use the correct EVM firmware? If you use the wrong option (pin mapping, PMIC, etc.) the system will not boot. Be sure to verify what configuration you are using with your EVM before proceeding.

    If you write the wrong firmware, you can still write new firmware to the flash device even if your system isn't booting.

    Regards,

    Philippe

  • Hi Philippe,

    I wrote the firmware of red LED only for our DLP4710EVM-LC with the following configuration:

    After the issue (explained in the previous post) with above firmware, I wrote the original firmware (downloaded from https://www.ti.com/tool/DLP4710EVM-LC) and tested it with no success. Following is our DLP setup:

    1) The DLP main electronic board is connected with LEDs, fans, and DMD

    2) DMD with its electronic card is mounted on a separate system but connected with DLP main electronic board with the flex cable.

    Is this the problem with DMD (with DMD electronic/interface card)? Is it possible we check separately the DMD is working or not?

    Hope for some guidance on this issue.

    Thank you

    Mumtaz

  • Mumtaz,

    I would recommend to assemble the EVM like it was before making any hardware change and try to test the original EVM firmware and check if you are able to get the display running. 

    Regards,

    Mayank

  • Hi Mayank,

    I tested the whole system by attaching fans and LEDs to the DLP mainboard but GUI shows "EVM Status: Connected, Powered Off". Is it possible we test DMD and/or the mainboard issues separately by using test pads/connections or some software utility?

    Hope for some guidance on this issue.

    Thank you

    Mumtaz

  • Mumtaz,

    Note you can still download firmware to the board even if it is not booting up. The flash update feature communicates directly with the SPI Flash device over USB so it is impossible to brick your system by flashing an incorrect firmware to your system.

    Are you able to use said flash update feature?

    - Philippe

  • Hi Philippe,

    Can you please tell me how I access the flash update feature? I can communicate with DLP through USB and only able to use the GUI firmware option (below snap). In the last test, I used original firmware with fans, LEDs, DMD connected but had no success.

    Available to provide more information, if needed.

    Thank you

    Mumtaz 

  • Mumtaz,

    The option you are using above is correct. Does the flash update complete successfully? Can you confirm you are using the original DLP4710-LC EVM Firmware from here: https://www.ti.com/tool/DLP4710EVM-LC 

    If so, you should confirm that you have everything connected properly and seated. If any of the LEDs are not connected properly or the DMD is not connected properly the system will fail to boot entirely.

    Regards,
    Philippe

  • Hi Philippe,

    Thanks for explaining the possible reasons. We will consider the mention points when we restart working on DLP.

    Best regards

    Mumtaz

  • Mumtaz,

    No problem. Let us know if you have further questions.

    Best Regards,

    Philippe