30 rt-thread ov2640 模拟iic 初始化失败

发布于 2020-11-30 23:19:25 浏览：1897 订阅该版

[tocm]

本人移植的官方ov2640（ART-PI）驱动程序，在stm32F429上接的微雪的扩展板子连得微雪的ov2640可以初始化成功也可以使用，但是最近迁到stm32f407上发现无法初始化成功。另外原子的自带晶振，以下是关键代码片段：
```c
static rt_err_t ov2640_read_id(struct rt_i2c_bus_device *bus)
{
    rt_uint8_t read_value[2];
    rt_uint16_t id = 0;
    read_reg(bus, OV2640_SENSOR_MIDH, 1, &read_value[0]);
    read_reg(bus, OV2640_SENSOR_MIDL, 1, &read_value[1]);
    id = ((rt_uint16_t)(read_value[0] << 8) & 0xFF00);
    id |= ((rt_uint16_t)(read_value[1]) & 0x00FF);

if (id != OV2640_MID)
    {
        LOG_E("ov2640 init error, mid: 0x%x    ", id);
        return RT_ERROR;
    }

LOG_I("ov2640 read mid success, mid: 0x%x    ", id);

read_reg(bus, OV2640_SENSOR_PIDH, 1, &read_value[0]);
    read_reg(bus, OV2640_SENSOR_PIDL, 1, &read_value[1]);
    id = ((rt_uint16_t)(read_value[0] << 8) & 0xFF00);
    id |= ((rt_uint16_t)(read_value[1]) & 0x00FF);

if (id != OV2640_PID)
    {
        LOG_E("ov2640 init error, pid: 0x%04x     ", id);
        return RT_ERROR;
    }

LOG_I("ov2640 read hid success, pid: 0x%04x", id);

return RT_EOK;
}
void rt_stm32407_atk_miniexpolre()
{
    GPIO_InitTypeDef GPIO_Initure;
    __HAL_RCC_GPIOG_CLK_ENABLE();           
   GPIO_Initure.Pin=GPIO_PIN_9|GPIO_PIN_15;//PG9,15  PG9---->PWDN  PG15------>RST
   GPIO_Initure.Mode=GPIO_MODE_OUTPUT_PP;  
   GPIO_Initure.Pull=GPIO_PULLUP;          
   GPIO_Initure.Speed=GPIO_SPEED_HIGH;     
   HAL_GPIO_Init(GPIOG,&GPIO_Initure);     
   rt_thread_mdelay(50);
   /* refence
   OV2640_PWDN=0;	//POWER ON
   delay_ms(10);
   OV2640_RST=0;	//
   delay_ms(10);
   OV2640_RST=1;	//
   */
  HAL_GPIO_WritePin(GPIOG,GPIO_PIN_9,GPIO_PIN_RESET);
  rt_thread_mdelay(10);
  HAL_GPIO_WritePin(GPIOG,GPIO_PIN_15,GPIO_PIN_RESET);
  rt_thread_mdelay(10);
  HAL_GPIO_WritePin(GPIOG,GPIO_PIN_15,GPIO_PIN_SET);
  rt_thread_mdelay(10);
  __HAL_RCC_GPIOD_CLK_ENABLE();           //
    
    //PD6.73?ê??ˉéè??
    GPIO_Initure.Pin=GPIO_PIN_6|GPIO_PIN_7;
    GPIO_Initure.Mode=GPIO_MODE_OUTPUT_PP;  //í?íìê?3?
    GPIO_Initure.Pull=GPIO_PULLUP;          //é?à-
    GPIO_Initure.Speed=GPIO_SPEED_FAST;     //?ì?ù
    HAL_GPIO_Init(GPIOD,&GPIO_Initure); 
  
   
}

int rt_ov2640_init(void)
{
    rt_uint16_t i = 0;
    rt_device_t dcmi_dev = RT_NULL;
    rt_stm32407_atk_miniexpolre();
    i2c_bus = rt_i2c_bus_device_find(I2C_NAME);
    if (i2c_bus == RT_NULL)
    {
        LOG_E("can't find %c deivce", I2C_NAME);
        return RT_ERROR;
    }
    write_reg(i2c_bus, OV2640_DSP_RA_DLMT, 0x01);
    rt_thread_delay(10);
    write_reg(i2c_bus, OV2640_SENSOR_COM7, 0x80);
    rt_thread_delay(500);
    ov2640_read_id(i2c_bus);

for (i = 0; i < sizeof(ov2640_svga_init_reg_tbl) / 2; i++)
    {
        write_reg(i2c_bus, ov2640_svga_init_reg_tbl[i][0], ov2640_svga_init_reg_tbl[i][1]);
    }

ov2640_rgb565_mode();
    ov2640_set_light_mode(0);
    ov2640_set_color_saturation(3);
    ov2640_set_brightness(4);
    ov2640_set_contrast(3);
    ov2640_jpeg_mode();
    ov2640_set_image_window_size(0, 0, 800,600);
    ov2640_set_image_out_size(800, 600);
    
    //ov2640_set_image_window_size(0, 0, 1200,800);
    //ov2640_set_image_out_size(1200, 800);

dcmi_dev = rt_device_find("dcmi");
    if (dcmi_dev == RT_NULL)
    {
        LOG_E("can't find dcmi device!");
        return RT_ERROR;
    }
    rt_device_open(dcmi_dev, RT_DEVICE_FLAG_RDWR);

jpeg_data_buf = rt_malloc(JPEG_BUF_SIZE);
   if (RT_NULL == jpeg_data_buf)
   {
       rt_kprintf("jpeg data buf malloc error!\n");
       return RT_ERROR;
   }

/* start dcmi capture 开启双缓冲*/
    //rt_hw_dcmi_dma_config((rt_uint32_t)JPEG_LINE0_BUF, (rt_uint32_t)JPEG_LINE1_BUF, JPEG_LINE_SIZE);
    rt_kprintf("camera init success!\n");
    return RT_EOK;
}
INIT_APP_EXPORT(rt_ov2640_init);
```
原子的初始化代码片段：
```c
u8 OV2640_Init(void)
{ 
	u16 i=0;
	u16 reg;
	//ÉèÖÃIO

GPIO_InitTypeDef GPIO_Initure;
    __HAL_RCC_GPIOG_CLK_ENABLE();			//¿ªÆôGPIOGÊ±ÖÓ
	
    GPIO_Initure.Pin=GPIO_PIN_9|GPIO_PIN_15;//PG9,15
    GPIO_Initure.Mode=GPIO_MODE_OUTPUT_PP;  //ÍÆÍìÊä³ö
    GPIO_Initure.Pull=GPIO_PULLUP;          //ÉÏÀ
    GPIO_Initure.Speed=GPIO_SPEED_HIGH;     //¸ßËÙ
    HAL_GPIO_Init(GPIOG,&GPIO_Initure);     //³õÊ¼»¯
		
		HAL_GPIO_WritePin(GPIOG,GPIO_PIN_9,GPIO_PIN_RESET);
  delay_ms(10);
  HAL_GPIO_WritePin(GPIOG,GPIO_PIN_15,GPIO_PIN_RESET);
  delay_ms(10);
  HAL_GPIO_WritePin(GPIOG,GPIO_PIN_15,GPIO_PIN_SET);
  delay_ms(10);
	
//	OV2640_PWDN=0;	//POWER ON
//	delay_ms(10);
//	OV2640_RST=0;	//¸´Î»OV2640
//	delay_ms(10);
//	OV2640_RST=1;	//½áÊø¸´Î» 
	
  	SCCB_Init();        		//³õÊ¼»¯SCCB µÄIO¿Ú	 
	SCCB_WR_Reg(OV2640_DSP_RA_DLMT, 0x01);	//²Ù×÷sensor¼Ä´æÆ÷
 	SCCB_WR_Reg(OV2640_SENSOR_COM7, 0x80);	//Èí¸´Î»OV2640
	delay_ms(50); 
	reg=SCCB_RD_Reg(OV2640_SENSOR_MIDH);	//¶ÁÈ¡³§¼ÒID ¸ß°ËÎ»
	reg<<=8;
	reg|=SCCB_RD_Reg(OV2640_SENSOR_MIDL);	//¶ÁÈ¡³§¼ÒID µÍ°ËÎ»
	if(reg!=OV2640_MID)
	{
		printf("MID:%d\r\n",reg);
		return 1;
	}
	printf("MID:%x\r\n",reg);
	reg=SCCB_RD_Reg(OV2640_SENSOR_PIDH);	//¶ÁÈ¡³§¼ÒID ¸ß°ËÎ»
	reg<<=8;
	reg|=SCCB_RD_Reg(OV2640_SENSOR_PIDL);	//¶ÁÈ¡³§¼ÒID µÍ°ËÎ»
	if(reg!=OV2640_PID)
	{
		printf("HID:%d\r\n",reg);
		//return 2;
	}
	printf("HID:%x\r\n",reg);
 	//³õÊ¼»¯ OV2640,²ÉÓÃSXGA·Ö±æÂÊ(1600*1200)  
	for(i=0;i<sizeof(ov2640_uxga_init_reg_tbl)/2;i++)
	{
	   	SCCB_WR_Reg(ov2640_uxga_init_reg_tbl[i][0],ov2640_uxga_init_reg_tbl[i][1]);
 	} 
  	return 0x00; 	//ok
} 
```

微雪的ov2640原理图：
![image.png](/uploads/20201130/dfb23a6771ae0e9b6fd99268816e894f.png)

原子的ov2640原理图：
![image.png](/uploads/20201130/37ac427b779340a524f0ec888ac3fd8f.png)

二者的区别SCL SDA应该是原子没有上拉
原子在模拟sscb初始化的时候gpio上拉了，
我的rtt下模拟iic的引脚定义
![image.png](/uploads/20201130/d6ec6ed6218b57b235524b7bf7497164.png)

目前现象初始化读id不正确，不知道哪里的问题。恳请大佬指点迷津
### 现在问题解决了一半了
![image.png](/uploads/20201201/83fa549ee75c7848d577ff1c2f658bd7.png)
现在可以读到id了，但是执行的时间太慢了啊。
![image.png](/uploads/20201201/50ab04524485f270fc0a1482000cc079.png)
90多秒钟才能配置完