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Ebun.1
Senior
February 24, 2021
Question

LTDC color and DE signal

  • February 24, 2021
  • 1 reply
  • 729 views

Thank you for helping.

MCU: STM32F769BI

Board: Custom

I set up LTDC using TouchGFX and STM32CubeIDE.

I thought that the RGB color signal would be output in synchronization with the DE signal.

When checked with an oscilloscope, the color signal (for example, R5) is output asynchronously with the DE signal.

Do I need to set the parameters of the LTDC to synchronize?

Please tell me how to synchronize.

Thank you.

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1 reply

Ebun.1
Ebun.1Author
Senior
February 24, 2021

Thank you for helping.

Supplement.

I will attach an image taken with an oscilloscope.

At the top is the R5 signal.

The middle is the DE signal.

The R5 and DE signals are out of sync.

I pasted a white image on the left half and a black image on the right half with TouchGFX.

So the signal of R5 should be H only in the first half of DE as shown at the bottom.

What should I do to synchronize the signals?

In software

Where does the color signal change?

Where is the place to change the DE signal?

Thank you.