[求助] 实在是没办法了请高手帮帮忙啊

sinianhuan 2012-10-10 17:16 楼主

最近在弄430I2C协议，不知道那里出问题了总是调不出来，我已经调试了两天了，今天测试程序连往芯片里写都没法写根本检测不到应答信号。使用的是MSP430F1611，晶振使用的4M晶振。希望有高手能帮我看看程序。

程序.zip (2012-10-10 17:16 上传)

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430程序

回复评论（3）

沙发 deweyled

可以用示波器看看430输出的波形是否满足24C02的访问时序

点赞 2012-10-10 19:18

板凳 sinianhuan

用示波器没看出波形来，可能是不大会用吧，我这里调试也挺麻烦的，几个人共用一个仿真器，示波器这边还没有，还得去别的地方用。

点赞 2012-10-12 13:53

以前写过，拿出来参考下

void I2C_init(void)
{
SET(PT(I2C_SCL_PORT,DIR,I2C_SCL_BIT));
CLR(PT(I2C_SCL_PORT,OUT,I2C_SCL_BIT));
}

void I2C_wait(void)
{
asm("NOP");
asm("NOP");
asm("NOP");
asm("NOP");
asm("NOP");
asm("NOP");
asm("NOP");
asm("NOP");
}

void I2C_ack(void)
{
SET(PT(I2C_SDA_PORT,DIR,I2C_SDA_BIT));
PT(I2C_SDA_PORT,OUT,I2C_SDA_BIT) = 0;
I2C_wait();

PT(I2C_SCL_PORT,OUT,I2C_SCL_BIT) = 1;
I2C_wait();

PT(I2C_SCL_PORT,OUT,I2C_SCL_BIT) = 0;
I2C_wait();
PT(I2C_SDA_PORT,OUT,I2C_SDA_BIT) = 1;
}

void I2C_noack(void)
{
SET(PT(I2C_SDA_PORT,DIR,I2C_SDA_BIT));
PT(I2C_SDA_PORT,OUT,I2C_SDA_BIT) = 1;
I2C_wait();

PT(I2C_SCL_PORT,OUT,I2C_SCL_BIT) = 1;
I2C_wait();

PT(I2C_SCL_PORT,OUT,I2C_SCL_BIT) = 0;
I2C_wait();
PT(I2C_SDA_PORT,OUT,I2C_SDA_BIT) = 1;
}

unsigned char I2C_start(void) //在scl高电平过程中，sda产生一个下降沿
{
SET(PT(I2C_SDA_PORT,DIR,I2C_SDA_BIT));
SET(PT(I2C_SDA_PORT,OUT,I2C_SDA_BIT));
I2C_wait();

SET(PT(I2C_SCL_PORT,OUT,I2C_SCL_BIT));
I2C_wait();

CLR(PT(I2C_SDA_PORT,DIR,I2C_SDA_BIT));
if(PT(I2C_SDA_PORT,IN,I2C_SDA_BIT) == 0)// SDA 为低，则说明有其他设备使用sda
   return 0;

SET(PT(I2C_SDA_PORT,DIR,I2C_SDA_BIT));
PT(I2C_SDA_PORT,OUT,I2C_SDA_BIT) = 0; //产生一个下降沿
I2C_wait();

PT(I2C_SCL_PORT,OUT,I2C_SCL_BIT) = 0;
I2C_wait();
PT(I2C_SDA_PORT,OUT,I2C_SDA_BIT) = 1;

return 1;
}

void I2C_stop(void)
{
SET(PT(I2C_SDA_PORT,DIR,I2C_SDA_BIT));
PT(I2C_SDA_PORT,OUT,I2C_SDA_BIT) = 0;
I2C_wait();

PT(I2C_SCL_PORT,OUT,I2C_SCL_BIT) = 1;
I2C_wait();
PT(I2C_SDA_PORT,OUT,I2C_SDA_BIT) = 1; // rasing edge
I2C_wait();

PT(I2C_SCL_PORT,OUT,I2C_SCL_BIT) = 0;
I2C_wait();
PT(I2C_SDA_PORT,OUT,I2C_SDA_BIT) =1;
}

unsigned char I2C_waitack(void)
{
unsigned int x = 0xffff;
SET(PT(I2C_SDA_PORT,DIR,I2C_SDA_BIT));
SET(PT(I2C_SDA_PORT,OUT,I2C_SDA_BIT));
I2C_wait();
CLR(PT(I2C_SDA_PORT,DIR,I2C_SDA_BIT));
I2C_wait();

PT(I2C_SCL_PORT,OUT,I2C_SCL_BIT) = 0;
I2C_wait();
PT(I2C_SCL_PORT,OUT,I2C_SCL_BIT) = 1;

while(PT(I2C_SDA_PORT,IN,I2C_SDA_BIT) == 1)
{
      x--;
      if(!x)
      {
         PT(I2C_SCL_PORT,OUT,I2C_SCL_BIT) = 0;
         return 0;
      }
}

PT(I2C_SCL_PORT,OUT,I2C_SCL_BIT) = 0;
SET(PT(I2C_SDA_PORT,DIR,I2C_SDA_BIT));
return 1;
}

void I2C_send_bit(unsigned char value)
{
SET(PT(I2C_SDA_PORT,DIR,I2C_SDA_BIT));

if(value != 0)
      PT(I2C_SDA_PORT,OUT,I2C_SDA_BIT) = 1;
else
      PT(I2C_SDA_PORT,OUT,I2C_SDA_BIT) = 0;
I2C_wait();

PT(I2C_SCL_PORT,OUT,I2C_SCL_BIT) = 1;
I2C_wait();

PT(I2C_SCL_PORT,OUT,I2C_SCL_BIT) = 0;
I2C_wait();
PT(I2C_SDA_PORT,OUT,I2C_SDA_BIT) = 1; //拉高sda，不影响其他设备使用sda
}

void I2C_send_byte(unsigned char value,unsigned char order)
{
unsigned char i;
SET(PT(I2C_SDA_PORT,DIR,I2C_SDA_BIT));

if(order == 1) //先发送高位，在发送低位
{
      for(i=0; i<8; i++)
      {
         I2C_send_bit(value & 0x80);
         value <<= 1;
      }
}
else//先发送低位，再发送高位
{
      for(i=0; i<8; i++)
      {
         I2C_send_bit(value & 0x01);
         value >>= 1;
      }
}
}

unsigned char I2C_receive_bit(void)
{
unsigned char c;


PT(I2C_SCL_PORT,OUT,I2C_SCL_BIT) = 1;
I2C_wait();

if(PT(I2C_SDA_PORT,IN,I2C_SDA_BIT) == 1)
      c = 1;
else
      c = 0;

PT(I2C_SCL_PORT,OUT,I2C_SCL_BIT) = 0;
I2C_wait();

return c;
}

unsigned char  I2C_receive_byte(unsigned char order)
{
unsigned char i, value = 0;
SET(PT(I2C_SDA_PORT,DIR,I2C_SDA_BIT));
SET(PT(I2C_SDA_PORT,OUT,I2C_SDA_BIT)); //将sda拉高,防止影响
CLR(PT(I2C_SDA_PORT,DIR,I2C_SDA_BIT));

if(order == 1) //数据从高位开始接收
{
      for(i = 0; i < 8; i++)
      {
         value <<= 1;
         if(I2C_receive_bit() == 1)
            value |= 0x01;
      }
}
else//数据从低位开始接收
{
      for(i = 0;i < 8; i++)
      {
         value >>= 1;
         if(I2C_receive_bit() == 1)
            value |= 0x80;
      }

}

SET(PT(I2C_SDA_PORT,DIR,I2C_SDA_BIT));
SET(PT(I2C_SDA_PORT,OUT,I2C_SDA_BIT));
return value;
}

set就是置1， clr 就是置0:

希望对你有帮助