OV7670 camera

[hitsumen]

Posted on February 15, 2012 at 08:55

Good day,

I have some problem here, I took some code from another project, I rewrote some parts. But my camera do not want to work. I just want to read the ID of camera through I2C (or so called SCCB), but I always get 0xFF. I even tried to scan all I2C devices (0x00-0xFF). Here is some code:

http://codepad.org/iohLbCkq

I use STM3210C-EVAL board with stm32f107 mcu. I connected camera to PB6 (SCL), PB7(SDA), 2.8V voltage and ground. Maybe I did something wrong, but I cannot find the mistake..sensor datasheet:

http://www.trulydisplays.com/ccm/specs/0.3M Sensor OV7670.pdf

and the camera:

http://www.emartee.com/Images/websites/emartee.com/products/thumbnails/big/41908.jpg

[mtaallah]

Posted on February 16, 2012 at 09:02

Hi,

The problem is that Alternate function are not configured. change

i2c_cfg

(

) as follow :

void

i2c_cfg

(

void

)

{

GPIO_InitTypeDef

GPIO_InitStructure

;

I2C_InitTypeDef

I2C_InitStruct

;

RCC_APB1PeriphClockCmd

(

RCC_APB1Periph_IOE_I2C

,

ENABLE

);

RCC_APB2PeriphClockCmd

(

RCC_APB_IOE_I2C_PORT

|

RCC_APB_GPIO_IOE_ITPORT

|

RCC_APB2Periph_AFIO

,

ENABLE

);

/* Alternate function configuration : modify parameters with your application requirement */  GPIO_PinAFConfig(

IOE_I2C_PORT

, GPIO_PinSource6, GPIO_AF_I2C1);  GPIO_PinAFConfig(

IOE_I2C_PORT

, GPIO_PinSource9, GPIO_AF_I2C1);   

/* Configure I2C1 GPIOs *****************************************************/

GPIO_InitStructure

.

GPIO_Pin

=

IOE_SCL_PIN

|

IOE_SDA_PIN

;

GPIO_InitStructure

.

GPIO_Mode

=

GPIO_Mode_AF

;

 

GPIO_InitStructure

.

GPIO_OType

=

GPIO_OType_OD

;

 

GPIO_InitStructure

.

GPIO_PuPd

=

GPIO_PuPd_NOPULL

;

 

GPIO_InitStructure

.

GPIO_Speed

=

GPIO_Speed_50MHz

;

GPIO_Init

(

IOE_I2C_PORT

,

&

GPIO_InitStructure

);

/* Configure I2C1 ***********************************************************/

/* I2C DeInit */

I2C_DeInit

(

I2C1

);

/* Enable the I2C peripheral */

I2C_Cmd

(

I2C1

,

ENABLE

);

/* Set the I2C structure parameters */

I2C_InitStruct

.

I2C_Mode

=

I2C_Mode_I2C

;

I2C_InitStruct

.

I2C_DutyCycle

=

I2C_DutyCycle_2

;

I2C_InitStruct

.

I2C_OwnAddress1

=

0xFE

;

I2C_InitStruct

.

I2C_Ack

=

I2C_Ack_Enable

;

I2C_InitStruct

.

I2C_AcknowledgedAddress

=

I2C_AcknowledgedAddress_7bit

;

I2C_InitStruct

.

I2C_ClockSpeed

=

30000

;

/* Initialize the I2C peripheral w/ selected parameters */

I2C_Init

(

I2C1

,

&

I2C_InitStruct

);

}

[hitsumen]

Posted on February 18, 2012 at 15:04

Hi Kurosaki,

Thank you for the reply.You see I took this code from another board, another cpu, but I2C Write and Read functions matches.I have STM3210C-EVAL board. It uses stm32f107 cpu. So the difference is that stm32f10x.h library:

http://www.keil.com/dd/docs/arm/st/stm32f10x/stm32f10x.h

typedef struct{  __IO uint32_t CRL;  __IO uint32_t CRH;  __IO uint32_t IDR;  __IO uint32_t ODR;  __IO uint32_t BSRR;  __IO uint32_t BRR;  __IO uint32_t LCKR;} GPIO_TypeDef;and stm32f2xx.h:

http://www.keil.com/dd/docs/arm/st/stm32f2xx/stm32f2xx.h

typedef struct{ __IO uint32_t MODER;__IO uint32_t OTYPER;__IO uint32_t OSPEEDR;__IO uint32_t PUPDR;__IO uint32_t IDR;__IO uint32_t ODR;__IO uint16_t BSRRL; /* BSRR register is split to 2 * 16-bit fields BSRRL */ __IO uint16_t BSRRH; /* BSRR register is split to 2 * 16-bit fields BSRRH */__IO uint32_t LCKR;__IO uint32_t AFR[2];} GPIO_TypeDef;

So in my library I do not see the function called:

GPIO_PinAFConfig(

IOE_I2C_PORT

, GPIO_PinSource6, GPIO_AF_I2C1); //6 SCL

GPIO_PinAFConfig(

IOE_I2C_PORT

, GPIO_PinSource7, GPIO_AF_I2C1); //7 SDA 

[armindavatgaran]

Posted on April 22, 2015 at 16:40

Hello

I can write to registers but can't read them, what is the reason?I supply xclk pin with 42MHz sysclk coming from MCO2.Thanks. 

[armindavatgaran]

Posted on June 28, 2015 at 16:26

Hello

My problem was solved,  it was related to the incompatibility of SCCB protocol and HAL_I2C_Mem_Read function of the stm32cubef4 software package.