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DLPLCRDC4422EVM: DLPLCRDC4422EVM: Failed to configure PWM out by DLPC4422 GUI

Part Number: DLPLCRDC4422EVM
Other Parts Discussed in Thread: DLPDLCR660TEVM, , DLPC4422, DLPC3439

Hi,

Thanks for your time.

My customer is using DLPLCRDC4422EVM and DLPDLCR660TEVM. Currently the system basically works fine. They can successfully display solid TPG pattern and external source. However customer failed to configure the GPIO PWM output. After change the value and click set, the command didn't work. If read back the register, the value will still be the original number.

Is there any special configuration needed of the PWM signal?

Their system and FPGA version are as below.

The GUI version is 1.0.

Please let me know if there is any additional information needed.

Best regards,

Kevin

  • Hello Kevin,


    Thank you for posting on the DLP E2E forums.
    I was able to replicate the same issues on our hardware and I also noticed some other weird behavior as well. 
    Let me look into this issue.

    In the meantime, may I ask what frequency and duty cycle your customer is using to configure the ports?
    Also have they noticed any error messages in the GUI when trying to configure the ports?

    Regards,
    Oscar

  • Hello Oscar,

    Appreciate for your reply.

    What my customer want to do is to use this PWM output and LED enable to design their own LED driver. So to your question:

    1. Customer suppose the frequency is 10KHz and duty cycle is 1-99.

    2. There was no error message.

    Best regards,

    Kevin

  • Kevin,

    The DLPC4422 EVM has an existing PWM SSI Driver Interface to be used with LED drivers. This interface contains the PWM and enable signals.
    The GUI also offers a "SSI" page under projector control in order to control the PWM and enable signals. (also supports SPI drivers) This is what we recommend for customers to use when trying to control a PWM Driver.

    Also there is a new LED Driver reference design that may prove useful to your customer in developing their LED driver. 

    Regards,
    Oscar

  • Hi Oscar,

    Thanks for your reply and reference design.

    What is the difference between using Driver Levels in SSI page and PWM output in PWM page? As they are configure the same PWM signal, right?

    By the way, it seems that customer also failed to configure the registers in SSI page. The same phenomenon as in PWM page.

    Best  regards,

    Kevin

  • Hello Oscar,

    Thanks for your reply.

    I tested  "Sequence Duty Cycle" and  " Driver levels:(PWM only)"  in "SSI" page of GUI.I could read the value, but I could not set it. I get the default value after i set new value. It seams it's just readable.

    My project only needs the blue LED, it's monochrome. So i just need two control signals:

    The first one is a blue LED switch signal. The blue LED switch signal should  synchronize with the projector data flame which is 50 or 60hz. After the system is powered on, it is only set once.

    The second one is a blue LED brightness signal. I want to use a PWM signal to control the LED driver board to achieve the brightness. The adjustment arrange is 1-1023 refer to dlpc3439, but it seams that dlpc4422 does not privode such adjustment arrange. After the system is powered on, it should be adjusted momentarily.

  • Hello Wang,

    The PWM signal when using the SSI page is configured at 18Khz with 1024 levels of adjustments. This is what you require correct?

    I also know why the GUI would not properly send the updated value. The firmware you downloaded was configured for a SPI driver. You will need a firmware that is configured for PWM drivers. 

    I will work with Kevin on getting you an updated project to work with PWM drivers, this will be faster than updated the TI.com firmware package.

    Regards,
    Oscar

  • Hello Oscar,

    Thanks for your reply.

    "The PWM signal when using the SSI page is configured at 18Khz with 1024 levels of adjustments.  This is what you require correct?"

    --That is what i need.

    I will contact Kevin for the new firmware.