configuration camera with 800*480 "RK043HR005" lcd with stm32f7508

[Bhanu]

Hi,

I'm trying to interface 400*400 camera with 800*480 lcd display.

i have done changes for lcd as per the datasheet but still im not getting output as expected.

​

before i have already interfaced 400*400 camera with 480*272 lcd display it's working fine, but now I'm trying to interface with 800*480 lcd.

[KDJEM.1]

Hello @Bhanu​,

Make sure that the VSYNC, HSYNC and LTDC clock are well configured.

I advise you, when you configured the LTDC, to get inspired from this article.

Kaouthar

[Bhanu]

Hi kaouthar,

​

I have already configured VSYNC,HSYNC and LTDC clock as per the datasheet.

but still I'm not getting camera image output as excepted. you can see below lcd output image which I'm getting and please find below attached video file for your reference. thank you.

[Bhanu]

Hi kaouthar,

i have configured the display now its working by changing the lcd and camera buffer size.

DCMI_HandleTypeDef *phdcmi;
 
 phdcmi->Init.CaptureRate = DCMI_CR_ALL_FRAME;
 phdcmi->Init.HSPolarity = DCMI_HSPOLARITY_LOW;
 phdcmi->Init.SynchroMode = DCMI_SYNCHRO_HARDWARE;
 phdcmi->Init.VSPolarity = DCMI_VSPOLARITY_HIGH;
 phdcmi->Init.ExtendedDataMode = DCMI_EXTEND_DATA_8B;
 phdcmi->Init.PCKPolarity = DCMI_PCKPOLARITY_RISING;
 phdcmi->Instance = DCMI;

but when i use "DCMI_CR_ALL_FRAME" camera output image is not changing

if i use "DCMI_CR_ALTERNATE_4_FRAME" instead of "DCMI_CR_ALL_FRAME" camera output image is displaying but the image displaying is slow.

And "FrameEventCallback" function not calling when i use "DCMI_CR_ALL_FRAME".

​

please help me to solve this issue.

thanks you

[KDJEM.1]

Hi @Bhanu​,

Glad to know that initial issue is already fixed.

Regarding the new issue: I recommend the “Application note Digital camera interface (DCMI) for STM32 MCUs�? (AN5020). This application note mentioned DCMI application examples with different capture modes. You can be based for these examples to verify your configuration.

Thank you for your contribution in STCommunity.

Kaouthar

[Bhanu]

Hi kaouthar,

Thanks for the reply.

​

Actually before when I use 400*272 lcd display with same camera its working fine with the "DCMI_CR_ALL_FRAME". But the thing is when i changed to the 800*480 lcd display its not working and I have already increased the buffer size also still I'm getting the same issue.

​

Thanks you

[Bhanu]

Hi kaouthar,

please let me know is anything i'm missing in configuration after changed the lcd resolution 480*272 to 800*480?

[KDJEM.1]

Hi @Bhanu​,

For 800x480 resolution, make sure that:

• The DMA configured for higher resolution. For that, I advise you to take a look at the AN5020 and precisely DMA configuration for higher resolutions Section.
• The frame buffer size is well calculated.

Note that, in case of SXGA frame with RGB data format, the user can reduce the resolution to display the received images on the LCD_TFT by using the resizing feature of the DCMI.

I hope this helps!

Thank you

Kaouthar

[Bhanu]

Hi kaouthar,

​

I have understand what you have said but the main reason i have changed display 480*272 to 800*480 because of camera.

my camera resolution 400*400 if i use previous lcd display i need to do cropping from DCMI image so i cant able to use total camera resolution so, hat why i have changed the display resolution to 800*480 and i have increase the buffer size too but still I'm not able to use "DCMI_CR_ALL_FRAME"

is their anything to do with SDRAM? I'm using 128Mbit SDRM

[Bhanu]

Hi Kaouthar,

waiting for your response to above reply

[KDJEM.1]

Hello @Bhanu​,

The resolution of LTDC and SDRAM are related. You can refer to this post and check if the 128Mbit SDRAM is able to support 800x480 resolution.

I suggest you take a look at this AN4861 Application note LCD-TFT display controller (LTDC) on STM32 MCUs and STM32F7-LTDC and precisely Two programmable LTDC layers section.

I hope this helps!

Thank you.

Kaouthar.