Skip to main content
radupaulstefan
radupaulstefan
Associate
February 21, 2016
Question

stm32f4 and ov7725

  • February 21, 2016
  • 4 replies
  • 1731 views
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.

    This topic has been closed for replies.

    4 replies

    Tesla DeLorean
    Tesla DeLorean
    Guru
    February 21, 2016
    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.

    Tips, Buy me a coffee, or three.. PayPal Venmo (See Profile) Up vote any posts that you find helpful, it shows what's working..
    radupaulstefan
    radupaulstefanAuthor
    Associate
    February 21, 2016
    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) .

    Tesla DeLorean
    Tesla DeLorean
    Guru
    February 21, 2016
    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.

    Tips, Buy me a coffee, or three.. PayPal Venmo (See Profile) Up vote any posts that you find helpful, it shows what's working..
    radupaulstefan
    radupaulstefanAuthor
    Associate
    February 21, 2016
    Posted on February 21, 2016 at 23:28

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

    Take care.

    Terms & ConditionsAccessibility statement