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stm32f4 and ov7725

radupaulstefan
Associate II
Posted on February 21, 2016 at 15:58

Hello everyone,

I just started working on a personal project that includes image processing using a STM32f4 nucleo and an OV7725 camera.So by my calculations for a 9 fps rate and a 640x480 resolution,the camera outputs a 6 MHz pixel clock. It means that I have to read each byte from the parallel output port with a frequency of 6 MHz wich let me just 13-14 ticks (84/6) to save the byte and do other tasks.So this makes impossible acquisition.

Could you guys give me an ideea how to manage this problem ? 

Thank you.

4 REPLIES 4
Posted on February 21, 2016 at 16:40

This is where you use DCMI and DMA, but you'd still actually have to do something with the data. May be you need to think about just how much horse-power you need.

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radupaulstefan
Associate II
Posted on February 21, 2016 at 18:13

Thank you for your advice,I just read about the DCMI, I'm affraid stm32f4 series doesn't support DCMI tough,I checked the datasheet and there's nothing about DCMI.Maybe I just need to choose another board like stm32f2 (which supports DCMI) .

Posted on February 21, 2016 at 18:31

The one on the Nucleo might not, it's a 64-pin device.

Look at the

http://www.st.com/web/en/resource/technical/document/reference_manual/DM00031020.pdf

for the STM32F4 devices, there is a whole chapter on DCMI

Thought of the Raspberry PI 2 running at 900 MHz, with 1GB of RAM? Something you might be able to do some video image capturing and processing with.

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radupaulstefan
Associate II
Posted on February 21, 2016 at 23:28

Thank you very much,now it's clear for me.

Take care.