How to connect stm32f746 to av camera?

[Mohammad Rostamian]

Posted on December 12, 2017 at 07:36

Hello

I want connect stm32f746 to av camera and show the camera picture or video on Lcd.

Can anybody suggest how i can do it?

Also can i use hdmi to show the video or picture on lcd with stm32f746?

Tanks

[AVI-crak]

Posted on December 12, 2017 at 11:15

AV is possible, but without color.

You need an external fast ADC on the DCMI bus, external sdram memory, some simple logic and three timers. It's very simple and fast. I use an analog camera to fix the contour of the cutting tool. External adc tvp5150am1, it was the cheapest.

There are ready solutions with a lower price, direct connection of the screen of any brand (without ST).

I apologize, the automatic translation module lives its own life.

[Mohammad Rostamian]

Posted on December 13, 2017 at 08:58

Hello

I can not understand your replay

Best regards.

[Imen.D]

Posted on December 12, 2017 at 17:09

Hello,

You have the AN4861 application note about LCD-TFT display controller (LTDC) and the  AN5020: Digital Camera Interface (DCMI) on STM32 MCUs, it will help you to understand the features, architecture and configuration of the DCMI with detailed examples.

I recommend that you download the schematic package of the STM32F7x board that you have selected and you find the camera type used in that board.

Best Regards

Imen

[Mohammad Rostamian]

Posted on December 12, 2017 at 19:17

Tank you Imen.

Your help is always  usefull.

My main problem is how can be an av cammera connected to micro?

I think, I have found solution. Using ADV7181 to convert av video to digital, then using DCMI to connect the ADV7181.

Thank you for your consideration.

[Tamas Novak]

Posted on December 14, 2017 at 11:01

I think you can't do it fine  directly with a STM32 if you use high-resolution (>800*600) cam+display.

You read camera stream with DCIM module, store to external SDRAM (as MCU doesn't have enough SRAM to hold screen),

probably do something with it (you may want to 'process' the picture), then read back to Chrome-ART and output to TFT controller.

Bandwidth needed may be roughly calculated as 1Mpixel * 2byte/pixel * 30fps = 60MBytes/sec. And you may count this more times:

- DMA from camera to external DRAM,

- DMA from external DRAM to internal SRAM buffer to process,

- DMA back to external SDRAM framebuffer,

- DMA read from ext DRAM to ChromeArt and TFT Controller. 

I think this can't be achived by a 300-400MHz MCU.  Go for  ARM A family chip...or pick a Raspberry Pi.

If you still want to use STM32 then you must use external hardware for high througput streams, MCU may only control the show.