msp430g2553硬件IIC

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msp430g2553硬件IIC [复制链接]

#include "msp430g2553.h"
#include "uart.h"

unsigned char RX_Data;
void I2C_Init(unsigned char SA);//I2C初始化，SA为从器件地址
void I2C_ReadData(unsigned char address);//I2C读出某一地址的数据
unsigned char I2C_WriteData(unsigned char address,unsigned char data);//I2C向某一地址写入数据
void delay(void);

void I2C_Init(unsigned char SA)
{
  P1SEL |= (BIT6 + BIT7);
  P1SEL2|= (BIT6 + BIT7);
  UCB0CTL1 |= UCSWRST;                      // Enable SW reset
  UCB0CTL0 = UCMST + UCMODE_3 + UCSYNC;     // I2C Master, synchronous mode
  UCB0CTL1 |= UCSSEL_2 + UCSWRST;            // Use SMCLK, keep SW reset
  UCB0BR0 = 30;                             // fSCL = SMCLK/80 = ~100kHz
  UCB0BR1 = 0;
  UCB0CTL0 &= ~UCSLA10; // 7位地址模式
  UCB0I2CSA = SA;                         // Slave Address is 2ch
  UCB0CTL1 &= ~UCSWRST;                     // Clear SW reset, resume operation
  delay();
}

unsigned char I2C_WriteData(unsigned char address,unsigned char data)
{
    while( UCB0CTL1& UCTXSTP );
    UCB0CTL1 |= UCTR;                // 写模式  
    UCB0CTL1 |= UCTXSTT;             // 发送启动位  

    UCB0TXBUF = address;           // 发送字节地址  
    // 等待UCTXIFG=1与UCTXSTT=0 同时变化等待一个标志位即可  
    while((IFG2 & UCB0TXIFG)==0)
    {  
        if( UCB0STAT& UCNACKIFG )      // 若无应答 UCNACKIFG=1  
        {  
            return 1;  
        }  
    }    

    UCB0TXBUF = data;          // 发送字节内容  
    while((IFG2 & UCB0TXIFG)==0);     // 等待UCTXIFG=1  

    UCB0CTL1 |= UCTXSTP;  
    while(UCB0CTL1& UCTXSTP);       // 等待发送完成  

    return 0;  
}

unsigned char I2C_WriteNData( unsigned char address, unsigned char *pWbuf, unsigned char len)  
{
    unsigned char i;    
  while( UCB0CTL1& UCTXSTP );  
  UCB0CTL1 |= UCTR;                // 写模式  
  UCB0CTL1 |= UCTXSTT;             // 发送启动位  

  UCB0TXBUF = address;           // 发送字节地址  
  // 等待UCTXIFG=1与UCTXSTT=0 同时变化等待一个标志位即可  
  while((IFG2 & UCB0TXIFG)==0)
  {  
        if( UCB0STAT& UCNACKIFG )      // 若无应答 UCNACKIFG=1  
        {  
            return 1;  
        }  
  }    

  for( i= 0; i < len; i++)  
  {  
    UCB0TXBUF = *pWbuf++;      // 发送寄存器内容  
    while(UCB0CTL1& UCTXSTP);   // 等待UCTXIFG=1     
  }  

  UCB0CTL1 |= UCTXSTP;  
  while(UCB0CTL1& UCTXSTP);       // 等待发送完成  

  return 0;  
}  
void I2C_ReadData(unsigned char address)
{
    UCB0CTL1 |= UCTR ;
    UCB0CTL1 |= UCTXSTT;             // I2C TX, start condition
    UCB0TXBUF = address;////eeprom low addr
    while((IFG2 & UCB0TXIFG)==0);
    UCB0CTL1 &= ~UCTR;             // I2C RX,
    UCB0CTL1 |= UCTXSTT;   
    while(UCB0CTL1&UCTXSTT);
    UCB0CTL1 |= UCTXSTP;
    while((IFG2&UCB0RXIFG)==0);
    RX_Data = UCB0RXBUF;
    while(UCB0CTL1 & UCTXSTP);
}

unsigned char  I2C_ReadNData(unsigned char address, unsigned char *pRead, unsigned char len )
{
    unsigned char i;
    while( UCB0CTL1& UCTXSTP );
    UCB0CTL1 |= UCTR; // 写模式
    UCB0CTL1 |= UCTXSTT; // 发送启动位和写控制字节
    UCB0TXBUF = address; // 发送字节地址
    // 等待UCTXIFG=1与UCTXSTT=0 同时变化等待一个标志位即可
    while((IFG2 & UCB0TXIFG)==0);
    UCB0CTL1 &= ~UCTR; // 读模式
    UCB0CTL1 |= UCTXSTT; // 发送启动位和读控制字节
    while(UCB0CTL1& UCTXSTT); // 等待UCTXSTT=0
    // 若无应答 UCNACKIFG = 1
    for( i= 0; i< len -1 ; i++)
    {
        while((IFG2&UCB0RXIFG)==0);  // 读取字节内容，不包括最后一个字节内容
        *pRead++= UCB0RXBUF;
    }
    UCB0CTL1 |= UCTXSTP; // 在接收最后一个字节之前发送停止位
    while((IFG2&UCB0RXIFG)==0); // 读取最后一个字节内容
    *pRead = UCB0RXBUF;
    while( UCB0CTL1& UCTXSTP );
    return 0;
}
void delay(void)
{
  unsigned int i,n;
  for(i=0;i<100;i++)
    for(n=0;n<0xff;n++);
}

int main( void )
{
    unsigned char ReadBuf[10];
    unsigned char temp = 1;
    // Stop watchdog timer to prevent time out reset
    WDTCTL = WDTPW + WDTHOLD;
    BCSCTL1=CALBC1_1MHZ;
    DCOCTL=CALDCO_1MHZ;
    Uart_Init();
    P1DIR |= BIT0;
    P1OUT |= BIT0;
    I2C_Init(0x51);//1010 000X>>1

    //I2C_WriteData(0x02,5);
    _EINT();
    //I2C_Init(0x51);//1010 000X>>1
    //I2C_ReadData(tUart.RecBuf[0]-0x30);
    while(1)
    {
        if(tUart.RecFlag)
        {
            tUart.RecFlag = 0;
            tUart.Len = 0;

            //I2C_Init(0x51);//1010 000X>>1
            //I2C_ReadData(tUart.RecBuf[0]-0x30);
            I2C_WriteData(0x03,temp++);
            I2C_ReadNData(0x02, ReadBuf, 8 );
            UartSendStr(ReadBuf);
            //UartSendByte(RX_Data);
        }
    }
}