Is Stm32f769IIT feasible with ST7701 and NT35510MH LCD IC driver?

[MYous.8]

I'm using DSI in video mode +LTDC in Stm32f769IITX to interface with LCD driver "ST7701"

and i am facing problems to display an image even i followed the manufacturer initialization sequence. so, i contacted with the the "ST7701" supplier which said that "STM mcu is not compatible with lcd driver "ST7701" ,"NT35510MH" as well.

[TDK]

> i contacted with the the "ST7701" supplier which said that "STM mcu is not compatible with lcd driver "ST7701" ,"NT35510MH" as well.

Seems like you got a pretty direct answer there. It's one thing if you read a random post that says something, but if the manufacturer of the LCD is saying it won't work, I would consider alternatives.

[MYous.8]

Hello,

I need more than "no". I need an answer for "why" to think in a work around solution and to make a better choice the next time.

[ari_v2]

Hi,

I'm also using the ST7701 lcd driver with stm32F469 and I'm facing problems.

Could you please tell me if you've solved your problem? Could you please share with me conclusions?

Thanks,

Ari

[MYous.8]

Unfortunately, we didn't know the problem of compatibility which make mcu using DSI didn't work with ST7701.

so we had to use RGB instead.

Wish you good luck

[JMD]

Hello,

Please, does somebody know why ST7701 is not compatible with STM32F4 or STM32F7 ?

Thank you.

Best regards.

[TDK]

Maybe contact the supplier? Or reference timing diagrams between reference manual and datasheet.

[ari_v2]

Hi all,

My board consists of stm32f469 and LCD with ST7701 controller, DSI interface.

The LCD works. But performance is not 100%. I'll be glad to share code.

I wonder if those that didn't succeed mean that , LCD didn't work at all or they experienced bad performance?

Ari

[JMD]

Hi ,

Thank you so much for your feedback, I am happy to listen your experience.

My supplier say to me I don't have any example with mipi :) so I am alone and ST7701 are used but with linux most of the time so the platform is different.

When I read It doesn't work I am a littlle ambarased because I have so many lcd screen with ST7701.

Performance is not an issue for the moment for me I just want to display 15-30 fps even if it is a partial screen.

There is an example with DSI and another controller for stm32469 and so one and some commands seems to be the same so I prepare a special PCB to verify the actual code in example to test with my LCD (ST7701) https://www.buydisplay.com/4-inch-tft-lcd-display-480x480-pixel-with-mipi-interface-for-iot-devices.

In few days I will received my custom board to test the LCD but I am anxious due too the non feasibility explain in first posts

Can you tell me more about performance "is not 100%" can I obtain 30 fps on 480*480 24 bits ?

I am very late on my project if you can share with me a little project or sample code to use my ST7701 LCD It will be really a gift for me just before holidays :)

Thank you so much.

[ari_v2]

Hi,

Please find attached. I hope it will help.

My LCD is 480*800 (Portrait).

Regarding performance, images on screen often are darker than expected, after changing screen I see faded "leftovers" from the previous screen and also some screens flicker, while others are stable. I don't know how to explain these problems.

[JMD]

Hi,

Thank you so much for the code.

Artefacts are maybe due to available bandwith or some timing that are not perfect ?

I will try soon and I will keep you inform on my LCD 480*480

Thank so much for your sharing.

Best regards,

Julien.

[Tesla DeLorean]

480x480x24bpp @ 60 Hz should be below 400 Mbps, well within the scope of a 2-lane DSI implementation

32-bit wide SDRAM?

DSIHOST needs to clock at least as fast as the LTDC spills data too it.

Data sheets are usually pretty explicit about the line totals and horizontal, vertical and pixel clocking expectations/ranges

On the STM32 side, watch for contending sources on the frame-buffer

It's been my experience with a lot of vendors, is they lack engineering talent and interest to spend hours explaining to end-users how to configure and program displays, or write drivers for random MCU and OSs

[ari_v2]

Hi,

My LCD is 480*800*16bpp @60 Hz, results to 368.64 mhz. SDRAM is 16 bit wide.

Please see attached clock configuration. Could you see any indication for bad performance? images on screen often are darker than expected, after changing screen I see faded "leftovers" from the previous screen and also some screens flicker, while others are stable.

Thanks