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花了幾天時間用stm32和ov7670搞了個圖像采集，這比我預想的要難很多。ov7670一百多個寄存器而且ov公司的datasheet簡陋得常常讓我想說一句：我去年買了個表。后來還是借鑒了網絡上的一些寄存器配置，在加上苦讀ov推出的資料終于還是搞出了個簡陋的摸樣出來。 話不多說了，給大家分享一下心得體會，以便幫助后面學習的朋友少走些彎路。 一：攝像頭不比其他的傳感器，有一定的難度，而且資料太過簡陋，后面學習的朋友盡量買些成熟產品做開發(fā)，比如說淘寶買的開發(fā)套件。我就吃了這虧，stm32和攝像頭完全從零做起，啥都沒有，連上位機都準備自己寫，這沒必要時間成本太高了。 二：不要指望自己一個一個寄存器去配置，本來資料就簡陋，有很多寄存器你看了資料未必能明白啥個意思，在網上找個配置方案（也可以借用我的配置方案）修改一些關鍵地方就行了。 三：注意焦距的調節(jié)，如果焦距調節(jié)不正確，可能畫面模糊一片，慢慢調節(jié)一下焦距圖像畫面應該就出來了（前提是你已經采集到了圖像） 四：注意SCCB（也就是I2C）的時序，可以借鑒我的初始化，但配置完成后用串口讀取一些寄存器的值打印出來，看是否配置成功，如果這個都沒有配置成功，你先別浪費時間找圖像了。 五：網上能下載到的上位機，一般都會顯示255的灰度圖像，而ov7670是不能夠輸出灰度圖像的，所以只能將輸出格式配置成為YUV，然后人為去掉UV，將Y傳給上位機顯示就是灰度圖像了。（注意網上下載的上位機軟件可能會有一些協議，最好先弄清楚，要不然你顯示肯定是顯示不出來的） 六：分辨率配置 （具體配置參考代碼）主要有一下幾個寄存器 0x 17 HSTART 0x 18 HSTOP 0x 19 VSTRT 0x 1A VSTOP 0x 03 VREF HREF 的高電平寬度等于我們所要顯示的一行 HREF = WEIGHT*2; 乘以二是因為每個像素點是有兩個 HSTOP=START + HREF; 184 + 320*2 = 824; 然后在用824對784求余就是HSTOP的值（其原因，請仔細度ov7670的時序，如果懶得看，直接用就行） 七：配置為YUV格式關鍵寄存器配置：（引用于網絡論壇，感謝他的分享） {0x12, 0x10},//QVGA YUV
{0x3a, 0x14},//使用固定UV輸出
{0x3d, 0x80},//使用固定UV輸出
{0x67, 0x11},//固定U值，0x11，方便測試
{0x68, 0xFF},//固定V值，0xFF，方便測試
{0x40, 0xC0},//初始配置，YUV模式，這個寄存器必須設置，否則不好使
為方便調試，都是用固定的U值和V值，
向67中寫入11，向68中寫入FF，出來的是XX11XXFF，說明配置成功。
要注意的就是{0x40, 0xC0}，這個必須設置成初始化值，默認配置便是YUV，不能再用RGB565的配置。順便說一句，YUV模式為YUV 4:2:2，不是說8位里面4位Y，2位U，2位V的意思， Y/U/V都是8位數據，只是U和V是隔著Y輪流輸出的，高字節(jié)的是Y，低字節(jié)為U或V，做飛思卡爾智能車一般用的OV7620就是這樣，一般只用Y的數據，用來判斷黑白。 八：我的程序說明，各引腳（懶得打字，請看圖片吧），串口用的是STM32的UART3，還有需要注意的是我是用一個外部按鍵作為一幀圖片的發(fā)送，每按一次發(fā)送幀的圖片信號，用的是PA3。 寄存器配置 void set_Cmos7670reg(void) { WrCmos7670(0x67, 0xaa); WrCmos7670(0x68,0x55); WrCmos7670(0x3a,0x14); WrCmos7670(0x40,0xC0); WrCmos7670(0x12,0x10); WrCmos7670(0x32,0x80); WrCmos7670(0x17,0x16); WrCmos7670(0x18,0x04); WrCmos7670(0x19,0x02); WrCmos7670(0x1a,0x7b); WrCmos7670(0x03,0x06); WrCmos7670(0x0c,0x00); WrCmos7670(0x3e,0x00); WrCmos7670(0x70,0x3a); WrCmos7670(0x71, 0x35); WrCmos7670(0x72,0x11); WrCmos7670(0x73,0x00); WrCmos7670(0xa2,0x02); WrCmos7670(0x11,0x81); WrCmos7670(0x7a,0x20); WrCmos7670(0x7b,0x1c); WrCmos7670(0x7c,0x28); WrCmos7670(0x7d,0x3c); WrCmos7670(0x7e,0x55); WrCmos7670(0x7f,0x68); WrCmos7670(0x80,0x76); WrCmos7670(0x81,0x80); WrCmos7670(0x82,0x88); WrCmos7670(0x83,0x8f); WrCmos7670(0x84,0x96); WrCmos7670(0x85,0xa3); WrCmos7670(0x86,0xaf); WrCmos7670(0x87,0xc4); WrCmos7670(0x88,0xd7); WrCmos7670(0x89,0xe8); WrCmos7670(0x13,0xe0); WrCmos7670(0x00,0x00); WrCmos7670(0x10,0x00); WrCmos7670(0x0d,0x00); WrCmos7670(0x14,0x28); WrCmos7670(0xa5,0x05); WrCmos7670(0xab,0x07); WrCmos7670(0x24,0x75); WrCmos7670(0x25,0x63); WrCmos7670(0x26,0xA5); WrCmos7670(0x9f,0x78); WrCmos7670(0xa0,0x68); WrCmos7670(0xa1,0x03); WrCmos7670(0xa6,0xdf); WrCmos7670(0xa7,0xdf); WrCmos7670(0xa8,0xf0); WrCmos7670(0xa9,0x90); WrCmos7670(0xaa,0x94); WrCmos7670(0x13,0xe5); WrCmos7670(0x0e,0x61); WrCmos7670(0x0f,0x4b); WrCmos7670(0x16,0x02); WrCmos7670(0x1e,0x37); WrCmos7670(0x21,0x02); WrCmos7670(0x22,0x91); WrCmos7670(0x29,0x07); WrCmos7670(0x33,0x0b); WrCmos7670(0x35,0x0b); WrCmos7670(0x37,0x1d); WrCmos7670(0x38,0x71); WrCmos7670(0x39,0x2a); WrCmos7670(0x3c,0x78); WrCmos7670(0x4d,0x40); WrCmos7670(0x4e,0x20); WrCmos7670(0x69,0x00); WrCmos7670(0x6b,0x60); WrCmos7670(0x74,0x19); WrCmos7670(0x8d,0x4f); WrCmos7670(0x8e,0x00); WrCmos7670(0x8f,0x00); WrCmos7670(0x90,0x00); WrCmos7670(0x91,0x00); WrCmos7670(0x92,0x00); WrCmos7670(0x96,0x00); WrCmos7670(0x9a,0x80); WrCmos7670(0xb0,0x84); WrCmos7670(0xb1,0x0c); WrCmos7670(0xb2,0x0e); WrCmos7670(0xb3,0x82); WrCmos7670(0xb8,0x0a); WrCmos7670(0x43,0x14); WrCmos7670(0x44,0xf0); WrCmos7670(0x45,0x34); WrCmos7670(0x46,0x58); WrCmos7670(0x47,0x28); WrCmos7670(0x48,0x3a); WrCmos7670(0x59,0x88); WrCmos7670(0x5a,0x88); WrCmos7670(0x5b,0x44); WrCmos7670(0x5c,0x67); WrCmos7670(0x5d,0x49); WrCmos7670(0x5e,0x0e); WrCmos7670(0x64,0x04); WrCmos7670(0x65,0x20); WrCmos7670(0x66,0x05); WrCmos7670(0x94,0x04); WrCmos7670(0x95,0x08); WrCmos7670(0x6c,0x0a); WrCmos7670(0x6d,0x55); WrCmos7670(0x6e,0x11); WrCmos7670(0x6f,0x9f); WrCmos7670(0x6a,0x40); WrCmos7670(0x01,0x40); WrCmos7670(0x02,0x40); WrCmos7670(0x13,0xe7); WrCmos7670(0x15,0x00); WrCmos7670(0x4f,0x80); WrCmos7670(0x50,0x80); WrCmos7670(0x51,0x00); WrCmos7670(0x52,0x22); WrCmos7670(0x53,0x5e); WrCmos7670(0x54,0x80); WrCmos7670(0x58,0x9e); WrCmos7670(0x41,0x08); WrCmos7670(0x3f,0x00); WrCmos7670(0x75,0x05); WrCmos7670(0x76,0xe1); WrCmos7670(0x4c,0x00); WrCmos7670(0x77,0x01); WrCmos7670(0x3d,0x80); WrCmos7670(0x4b,0x09); WrCmos7670(0xc9,0x60); WrCmos7670(0x41,0x38); WrCmos7670(0x56,0x40); WrCmos7670(0x34,0x11); WrCmos7670(0x3b,0x02); WrCmos7670(0xa4,0x89); WrCmos7670(0x96,0x00); WrCmos7670(0x97,0x30); WrCmos7670(0x98,0x20); WrCmos7670(0x99,0x30); WrCmos7670(0x9a,0x84); WrCmos7670(0x9b,0x29); WrCmos7670(0x9c,0x03); WrCmos7670(0x9d,0x4c); WrCmos7670(0x9e,0x3f); WrCmos7670(0x78,0x04); WrCmos7670(0x79,0x01); WrCmos7670(0xc8,0xf0); WrCmos7670(0x79,0x0f); WrCmos7670(0xc8,0x00); WrCmos7670(0x79,0x10); WrCmos7670(0xc8,0x7e); WrCmos7670(0x79,0x0a); WrCmos7670(0xc8,0x80); WrCmos7670(0x79,0x0b); WrCmos7670(0xc8,0x01); WrCmos7670(0x79,0x0c); WrCmos7670(0xc8,0x0f); WrCmos7670(0x79,0x0d); WrCmos7670(0xc8,0x20); WrCmos7670(0x79,0x09); WrCmos7670(0xc8,0x80); WrCmos7670(0x79,0x02); WrCmos7670(0xc8,0xc0); WrCmos7670(0x79,0x03); WrCmos7670(0xc8,0x40); WrCmos7670(0x79,0x05); WrCmos7670(0xc8,0x30); WrCmos7670(0x79,0x26); WrCmos7670(0x09,0x00); } 圖片采集發(fā)送 void EXTI1_IRQHandler(void) { u16 i,j,k=0; u8 t1,t2; EXTI_InitTypeDefEXTI_InitStructure; NVIC_InitTypeDefNVIC_InitStructure; EXTI_ClearITPendingBit(EXTI_Line1); Vsync_Flag++; if(Vsync_Flag==1) //FIFOD { GPIO_SetBits(GPIOE,GPIO_Pin_5); //FIFO_WRST=1; __asm{nop;} GPIO_ResetBits(GPIOE,GPIO_Pin_5); //FIFO_WRST=0; delay_us(2); GPIO_SetBits(GPIOE,GPIO_Pin_5); //FIFO_WRST=1; GPIO_SetBits(GPIOE,GPIO_Pin_3); } if(Vsync_Flag==2) { GPIO_ResetBits(GPIOE,GPIO_Pin_3); //FIFO_WR=0; //½ûÖ1êy¾YD′èëFIFO EXTI->IMR&=~(1<<4); //1رÕía2¿ÖD¶Ï EXTI->EMR&=~(1<<4); EXTI_InitStructure.EXTI_Line= EXTI_Line1; EXTI_InitStructure.EXTI_Mode= EXTI_Mode_Interrupt; EXTI_InitStructure.EXTI_Trigger= EXTI_Trigger_Falling; EXTI_InitStructure.EXTI_LineCmd= DISABLE; EXTI_Init(&EXTI_InitStructure); // NVIC_InitStructure.NVIC_IRQChannel= TIM2_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority= 0; NVIC_InitStructure.NVIC_IRQChannelSubPriority= 0; NVIC_InitStructure.NVIC_IRQChannelCmd= DISABLE; NVIC_Init(&NVIC_InitStructure); // GPIO_SetBits(GPIOE,GPIO_Pin_4); //FIFO_RCK=1; GPIO_ResetBits(GPIOE,GPIO_Pin_6); //FIFO_RRST=0; //¶áÖ¸Õë¸′λ GPIO_ResetBits(GPIOE,GPIO_Pin_4); //FIFO_RCK=0; __asm{nop;}__asm{nop;} GPIO_SetBits(GPIOE,GPIO_Pin_4); //FIFO_RCK=1; __asm{nop;}__asm{nop;} GPIO_ResetBits(GPIOE,GPIO_Pin_4); //FIFO_RCK=0; GPIO_SetBits(GPIOE, GPIO_Pin_6); //FIFO_RRST=1; __asm{nop;} delay_us(2); GPIO_ResetBits(GPIOE,GPIO_Pin_2); //FIFO_OE=0;// __asm{nop;} USART3_Putc(0xff); //請注意：這里是發(fā)送協議信號，不是圖像信號 for(i = 0; i< 9600; i++) { for(j = 0; j < 8; j ++) { GPIO_ResetBits(GPIOE,GPIO_Pin_4);//FIFO_RCK=0; __asm{nop;} GPIO_SetBits(GPIOE,GPIO_Pin_4); //FIFO_RCK=1; __asm{nop;} t1=(0x00ff&GPIOC->IDR); GPIO_ResetBits(GPIOE,GPIO_Pin_4);//FIFO_RCK=0; __asm{nop;} GPIO_SetBits(GPIOE,GPIO_Pin_4); //FIFO_RCK=1; __asm{nop;} t2=(0x00ff&GPIOC->IDR); USART3_Putc(t1); } k=0; // } GPIO_SetBits(GPIOE,GPIO_Pin_2); //FIFO_OE=1; Vsync_Flag=0; NVIC_InitStructure.NVIC_IRQChannel= TIM2_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority= 0; NVIC_InitStructure.NVIC_IRQChannelSubPriority= 0; NVIC_InitStructure.NVIC_IRQChannelCmd= ENABLE; NVIC_Init(&NVIC_InitStructure); EXTI->IMR|=(1<<4); EXTI->EMR|=(1<<4); } } 最后上圖才有真相，電路雖然丑點但是可以用的。
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