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Random color pixel problem

erkanc
Associate III

Hi everyone. 

I set a flag, and checked it in handleTickEvent of any page. I give new location to images when the flag is set. I have a problem in this point. Sometimes(approximately 1/50 flag set), i see random color on some pixels. I research this problem at now. Do you have any idea about this problem? If i can find source of this problem, i will think the solution. 

I need to ideas about source of this problem. 

I have take many photos about this problem. You see that in following SS.

Info:

  • STM32G0B1
  • EXT FLASH IC

 

IMG_20240302_174305.jpgIMG_20240302_174423.jpgIMG_20240302_174815.jpgIMG_20240302_180001.jpg

Best regards,

1 ACCEPTED SOLUTION

Accepted Solutions
erkanc
Associate III

I probably caught the problem. I used double TFT that one of them is on custom board and other one connected by cables about 200mm lenght. And I connected as parallel each other without TE pin. I only used the TE pin of custom board TFT. And this problem solved. Probably, Pin's cables should not be length. 

In following SS:
TFT that is connected with 200mm length cable, TE pin was connected to MCU. Custom board TFT has clear image but there are random pixel colors on TFT that is connected cables.

I hope this information may help otherones.

@MM..1 you're right. This problem was specific. So I thought that this informations is enough for community. Or rather, I didn't know which information is need about this problem. Thank you for your interest.

Custom board TFT(MCU): ST7789V 

Other(connected with 200mm cables) TFT(MCU): ST7789P3

tft.jpg

View solution in original post

4 REPLIES 4
MM..1
Chief II

Your info lacks info... How buffer method , how display bus ...

erkanc
Associate III

I probably caught the problem. I used double TFT that one of them is on custom board and other one connected by cables about 200mm lenght. And I connected as parallel each other without TE pin. I only used the TE pin of custom board TFT. And this problem solved. Probably, Pin's cables should not be length. 

In following SS:
TFT that is connected with 200mm length cable, TE pin was connected to MCU. Custom board TFT has clear image but there are random pixel colors on TFT that is connected cables.

I hope this information may help otherones.

@MM..1 you're right. This problem was specific. So I thought that this informations is enough for community. Or rather, I didn't know which information is need about this problem. Thank you for your interest.

Custom board TFT(MCU): ST7789V 

Other(connected with 200mm cables) TFT(MCU): ST7789P3

tft.jpg

GaetanGodart
ST Employee

Hello @erkanc ,

 

So setting tearing effect interrupt pins have solved your issue?

If so, could you select your comment as best answer so other can find the solution quickly and so that I can close this thread?

 

Regards,

Gaetan Godart
Software engineer at ST (TouchGFX)

I tested many hours. Yes, when I abridged the all of data cables, this problem is solved. I didn't run into again with this problem. I waited the test results for feedback. If I run into the any problem like this, i will write here again.