NHD-3.5-320240FT-CSXN-CTP blank screen due to EMI

rifrifo

• June 16, 2020 10:07

Hello,

We have a system in U1 rack enclosure where a supply feeds around 250V, 1.5A periodically for a short time.

We have a NHD-3.5-320240FT-CSXN-CTP on the enclosure. Most of the time everything runs smoothly but sometimes during this power surges
the LCD goes black screen but the communication is perfectly fine.

 We loop through the below cycle without any errors.
   update,
   render,
   wait_swap

what goes wrong that causes this error? How can we detect this? Are there any registers that we should read

Best Regards

0

• 

  Ted M.

  NHD Staff

  • June 16, 2020 11:07

  Hi rifrifo,
  
  It may be that the FT813 EVE2 is still active and receiving commands, but the TFT's internal NV3035C controller has been affected by the power surge.
  In this case, the TFT would need to be reset and reinitialized in order to restore communications to the FT813.
  It may be necessary to provide additional grounding to the TFT's frame, or provide additional source voltage filtering in order to prevent the chances of the power surge from disrupting the TFT.
  
  Best Regards,

  0
• 

  rifrifo

  • June 16, 2020 12:07

  Hello Ted,
  
  Thank you for your answer. Is there a way to check whether NV3035C needs a reset or not?
  
  I can reset FT813 periodically but this is something I would not prefer.
  
  Thanks

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• 

  Ted M.

  NHD Staff

  • June 18, 2020 12:07

  Hi rifrifo,
  
  There may not be an easy way to detect this condition using FTDI's software commands.
  With power surges and ESD strikes, a power cycle may be the best way to clear the error and reinitialize the hardware and software when the TFT becomes unresponsive.
  
  Best Regards,

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• 

  rifrifo

  • June 23, 2020 12:07

  hmm, that's really bad,
  
  This means that I really have to reset the LCD periodically.
  
  Thank you for your time.

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