花了幾天時(shí)間用stm32和ov7670搞了個(gè)圖像采集,這比我預(yù)想的要難很多。ov7670一百多個(gè)寄存器而且ov公司的datasheet簡(jiǎn)陋得常常讓我想說(shuō)一句:我去年買了個(gè)表。后來(lái)還是借鑒了網(wǎng)絡(luò)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(gè)簡(jiǎn)陋的摸樣出來(lái)。 話不多說(shuō)了,給大家分享一下心得體會(huì),以便幫助后面學(xué)習(xí)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(guò)簡(jiǎn)陋,后面學(xué)習(xí)的朋友盡量買些成熟產(chǎn)品做開(kāi)發(fā),比如說(shuō)淘寶買的開(kāi)發(fā)套件。我就吃了這虧,stm32和攝像頭完全從零做起,啥都沒(méi)有,連上位機(jī)都準(zhǔn)備自己寫(xiě),這沒(méi)必要時(shí)間成本太高了。 二:不要指望自己一個(gè)一個(gè)寄存器去配置,本來(lái)資料就簡(jiǎn)陋,有很多寄存器你看了資料未必能明白啥個(gè)意思,在網(wǎng)上找個(gè)配置方案(也可以借用我的配置方案)修改一些關(guān)鍵地方就行了。 三:注意焦距的調(diào)節(jié),如果焦距調(diào)節(jié)不正確,可能畫(huà)面模糊一片,慢慢調(diào)節(jié)一下焦距圖像畫(huà)面應(yīng)該就出來(lái)了(前提是你已經(jīng)采集到了圖像) 四:注意SCCB(也就是I2C)的時(shí)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(lái),看是否配置成功,如果這個(gè)都沒(méi)有配置成功,你先別浪費(fèi)時(shí)間找圖像了。 五:網(wǎng)上能下載到的上位機(jī),一般都會(huì)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(jī)顯示就是灰度圖像了。(注意網(wǎng)上下載的上位機(jī)軟件可能會(huì)有一些協(xié)議,最好先弄清楚,要不然你顯示肯定是顯示不出來(lái)的) 六:分辨率配置 (具體配置參考代碼)主要有一下幾個(gè)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?yàn)槊總(gè)像素點(diǎn)是有兩個(gè) HSTOP=START + HREF; 184 + 320*2 = 824; 然后在用824對(duì)784求余就是HSTOP的值(其原因,請(qǐng)仔細(xì)度ov7670的時(shí)序,如果懶得看,直接用就行) 七:配置為YUV格式關(guān)鍵寄存器配置:(引用于網(wǎng)絡(luò)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(cè)試
{0x68, 0xFF},//固定V值,0xFF,方便測(cè)試
{0x40, 0xC0},//初始配置,YUV模式,這個(gè)寄存器必須設(shè)置,否則不好使
為方便調(diào)試,都是用固定的U值和V值,
向67中寫(xiě)入11,向68中寫(xiě)入FF,出來(lái)的是XX11XXFF,說(shuō)明配置成功。
要注意的就是{0x40, 0xC0},這個(gè)必須設(shè)置成初始化值,默認(rèn)配置便是YUV,不能再用RGB565的配置。順便說(shuō)一句,YUV模式為YUV 4:2:2,不是說(shuō)8位里面4位Y,2位U,2位V的意思, Y/U/V都是8位數(shù)據(jù),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(shù)據(jù),用來(lái)判斷黑白。 八:我的程序說(shuō)明,各引腳(懶得打字,請(qǐng)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(gè)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(hào),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(qǐng)注意:這里是發(fā)送協(xié)議信號(hào),不是圖像信號(hào) 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(diǎn)但是可以用的。
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