Test Pattern on NHD-3.5-320240MF-ATXL#-T-1 not working

Valin6210

• March 04, 2020 08:00

Hello,

This is my first foray into LCDs and Touchscreens.  The system is using a PIC processor to communicate/control the NewHaven display. 

There is power and the 3-wire SPI interface is connected with good data, SS and clk.  CLKIN is running at 6.6Mhz.  Have control of the Reset and hold it in Reset for 50 uSec after the PIC boots.

Backlight is working but that's just a PWM LED control and not related to any control registers.

Attempting to turn on a test pattern just to validate the NV3035C controller is reacting to the SPI commands and turn on the display. 

The display does not appear to be turning on and does not display a test pattern (SPI data sent is 0x02B3, register address 0, write bit, test pattern B, PWM disabled, Standby set to Normal Operation, ResetB set to not reset (tried RESETB both ways).

Any assistance is most appreciated.

Cheers...

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  Valin6210

  • March 04, 2020 09:07

  Update:
  
  The Touchscreen is receiving the SPI data and setting the display, however the display remains black until a push-button-reset resets the PIC processor, then the test pattern shows up until the PIC comes back on-line. 
  
  As I said before the only pins that are currently constrained/controlled are the SPI interface, RESET and CLKIN.  I have tried grounding all of those pins and none of them cause the display to turn on.
  
  Could the floating of either the VSYNC/HSYNC or any of the RGB lines be causing this behavior?
  
  Update 2: had the Backlight PWM turned off, so screen was dark, turned it up and lo and behold the test pattern appeared...sometimes it's the little things.

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  Ted M.

  NHD Staff

  • March 10, 2020 09:07

  Hi Valin6210,
  
  Thanks for the update. It's good to hear you have this working!
  
  Regards,

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