OV7670花屏异常描述及解决

最新推荐文章于 2025-04-24 00:46:02 发布

苏墨实验室

最新推荐文章于 2025-04-24 00:46:02 发布

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分类专栏：杂项

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本文记录了一次使用STM32F103和OV7670摄像头进行图像识别时遇到的问题及解决过程。在更换PCBA后，图像显示出现大量噪点，通过调整刷新率从60pcs降至30pcs解决了花屏问题。分析指出，异常可能由工作电压不稳定引起，导致通信错误率增加。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

前端时间用STM32F103+OV7670做简单图像识别，程序已经搞定并测试OK了，今天刚好收到新的PCBA，于是烧好程序测试下，发现工作不正常！于是把数据抓到电脑上：花屏了......没办法，只能一顿故障查找，详述如下。

无图无真相，先上图，可以看到有大量噪点，但能够显示物体样貌，中部黑色阴影部分是一条黑色电线。

在旧版PCBA上调试OV7670并通过串口在电脑上显示彩色图像，为了摄像头采集速度调解了PLL将刷新率提高到了60pcs，测试效果OK。换了新的PCBA后同样的程序测试有些花屏，即：图像能够显示，但有很多随机的噪点盖在图像上。所使用的程序和摄像头与第1步中的完全相同，哪都没查到原因，后来将刷新率降到30pcs就一切正常了。

注：我用的摄像头是单单的一个FPC排线连接的那种，上述两板PCBA的摄像头驱动电路是有区别的，后来测试发现工作电压稍有异常，但调整工作电压后依然无法在60pcs条件下正常显示。对于该异常现象，个人认为很可能还是工作电压有异常，使PLL及IO通信等稳定性降低，导致通信出现一定的错误率，进而产生了噪点；刷新率降低后，通信容错能力增强，故而噪点消失。

附录1。OV7670初始化是调整刷新率的寄存器。

附录2。OV7670+FIFO的标准电路。

附录3：OV7670配置。有同学需要，这里更新下，附上初始化配置程序。

//-------------------------------------------------------------------------------------
//函数名称：void set_Cmos7670reg(void)
//函数功能：OV7670初始化配置
//入口参数：无
//出口参数：无
//其他说明：
//-------------------------------------------------------------------------------------
void set_Cmos7670reg(void)
{

   WrCmos7670(0x3a, 0x04);
   WrCmos7670(0x40, 0xd0);
   WrCmos7670(0x12, 0x14);
   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, 0xe0);                       //设置PLL倍频,提高运行频率,赋值0x60为30pcs,0xe0为60pcs.
   WrCmos7670(0x6b, 0x60);                           //30pcs

   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, 0xc2);
   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);
}