Skip to main content
khouja_houssem
Associate III
September 12, 2013
Question

DCMI interface + camera module

  • September 12, 2013
  • 3 replies
  • 969 views
Posted on September 12, 2013 at 20:27

Hi,

I am trying to interface the OV5642 camera module with the STM32F4 microcontroller. 

So I wanted to ask about the XCLK signal in the camera, should it stay NC, or should I connect it to a clock (10Mhz to 24Mhz clock), or maybe I can generate that clock signal from the STM32F4 controller.

What do you suggest?
    This topic has been closed for replies.

    3 replies

    Tesla DeLorean
    Guru
    September 12, 2013
    Posted on September 12, 2013 at 21:30

    A cursory review of the

    http://www.uctronics.com/download/cam_module/ov5642.zip

    indicate you need to provide a clock. Something synchronous with the STM32F4 at 6-27 MHz would be fine.

    You should be able to generate 24 MHz via an APB2 TIM from 168 MHz, perhaps also MCO2 via PLLI2S. You could get 8 MHz via MCO/HSE
    Tips, Buy me a coffee, or three.. PayPal VenmoUp vote any posts that you find helpful, it shows what's working..
    michaelmccartyeng
    Associate III
    September 12, 2013
    Posted on September 12, 2013 at 22:04

    /**
    * @brief Set PA8 Output SYSCLK/2.
    * @param None
    * @retval None
    */
    void MCO1_Init(void)
    {
    GPIO_InitTypeDef GPIO_InitStructure;
    RCC_ClockSecuritySystemCmd(ENABLE);
    /* Enable GPIOs clocks */
    RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
    GPIO_PinAFConfig(GPIOA, GPIO_PinSource8, GPIO_AF_MCO);
    /* Configure MCO (PA8) */
    GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8;
    GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
    GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
    GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
    GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP; 
    GPIO_Init(GPIOA, &GPIO_InitStructure);
    RCC_MCO1Config(RCC_MCO1Source_PLLCLK, RCC_MCO1Div_3);
    }

    khouja_houssem
    Associate III
    September 13, 2013
    Posted on September 13, 2013 at 22:27

    Thanks again for your help!! ^^

    So if I use the HSE clock as a source with RCC_MCO1Div_1, I will get 8Mhz.

    Does it work that way I just want to make sure cause I don't have an oscilloscope to verify it.