MSP430杂谈--AD7793硬件SPI驱动与模拟SPI驱动

最近项目中用到了AD7793读取铂电阻值来得到相应的温度，编写了基于MSP430的硬件驱动程序和模拟驱动程序，并且能成功运行，现在记录一下分享给大家。
AD7793硬件IIC驱动完整版下载链接：https://download.csdn.net/download/qq_42580947/11041933
AD7793模拟IIC驱动完整版下载链接：https://download.csdn.net/download/qq_42580947/11041961
PS：目前资源积分无法自行调整，有谁知道可以修改积分的方法请告知，我想免费分享给大家。
 
1. AD7793硬件SPI驱动
单片机型号为：MSP430F57XX
硬件SPI驱动失败的几个原因有：单片机配置SPI资源错误（包括SPI的时钟，SPI的运行模型等配置错误），单片机的系统时钟配置错误（注意MCLK, SMCLK, ACLK的分配）
1.1 SPI read with AD7793

/******************** SPI read with AD7793 ***********************/void AD7793_R(unsigned char addr, unsigned char *buffer, int n){  unsigned int index;  unsigned char temp;  AD7793_CS_DIS;  __delay_cycles(200);   AD7793_CS_EN;    // t1>0ns  __delay_cycles(200);   // send address  while(!(UCB0IFG & UCTXIFG));                  UCB0TXBUF = addr;  while(!(UCB0IFG & UCRXIFG));                temp = UCB0RXBUF;  // Delay > 10us, after writing to RAM  Delay10us(2);      // Read data from register and load in buffer[]  for(index=0; index < n; index++)  {    while(!(UCB0IFG & UCTXIFG));                  UCB0TXBUF = 0x00;    while(!(UCB0IFG & UCRXIFG));                buffer[index] = UCB0RXBUF;    Delay10us(100);  }    AD7793_CS_DIS;}1.2 SPI write with AD7793

/******************** SPI write with AD7793 ***********************/void AD7793_W(unsigned char addr, unsigned char *buffer, char n){  unsigned char index;    AD7793_CS_EN;    // t1>0ns  __delay_cycles(200);   // send address  while(!(UCB0IFG & UCTXIFG));                UCB0TXBUF = addr;    // Delay > 10us, after writing to RAM  Delay10us(2);      // Read data from register and load in buffer[]  for(index=0; index < n; index++)  {    while(!(UCB0IFG & UCTXIFG));                UCB0TXBUF = buffer[index];  }   AD7793_CS_DIS;  }1.3 AD7793 相关寄存器配置

/******************** AD7793 Configuration ***********************/void AD7793_CON(void){  AD7793_CS_EN;    //single model  SPI_Data[0] = 0x20;    //64k intenal CLK，4.17Hz update rate（stable time 500ms）  SPI_Data[1] = 0x0f;                     //Model regeister  AD7793_W(0x08, SPI_Data, 2);    AD7793_CS_DIS;  }1.4 电压测量

/******************** voltage measurement ***********************/void V_measure (void){ /*** Read the both sides voltage of RTD ***/    //bioplar encoding, 8 times, input range 312.5mV  //external reference voltage, buffer mode, AIN1 input  AD7793_CON();  SPI_Data[0] = 0x03;  SPI_Data[1] = 0x10;                       AD7793_W(0x10, SPI_Data, 2);    //IEXC1,IEXC2 connected with IOUT1，current is 210uA  //IO register  SPI_Data[0] = 0x0E;  AD7793_W(0x28, SPI_Data, 1);  //data register  AD7793_R(0x58, SPI_Data, 3);  //get the temperature values  ad_result_T = SPI_Data[0];  ad_result_T <<= 8;  ad_result_T += SPI_Data[1];  ad_result_T <<= 8;  ad_result_T += SPI_Data[2];  ad_result_T &= 0x00ffffff;  ad_result_T -= 8388608;  T =(float)ad_result_T*3.7104E-5;   /*** Read the ambient temperature ***/    //bioplar encoding, 8 times, input range 312.5mV  //external reference voltage, buffer mode, AIN1 input  SPI_Data[0] = 0x00;  SPI_Data[1] = 0x86;                       AD7793_W(0x10, SPI_Data, 2);  //data register  AD7793_R(0x58, SPI_Data, 3);  //get the ambient temperature  ad_result_T1 = SPI_Data[0];  ad_result_T1 <<= 8;  ad_result_T1 += SPI_Data[1];  ad_result_T1 <<= 8;  ad_result_T1 += SPI_Data[2];  ad_result_T1 &= 0x00ffffff;  ad_result_T1 -= 8388608;  Tenvir =(float)ad_result_T1*3.7104E-5;}2. AD7793模拟SPI驱动
模拟SPI驱动失败的最主要原因是：时钟！时钟！时钟！注意时钟的配置和延时的处理
2.1 AD7793基础子函数的处理

void AD7793_CS_SET()//CS置1{    P1OUT |= BIT1; }void AD7793_CS_CLR()//CS置0{    P1OUT &=~ BIT1; }void AD7793_SCLK_SET(){    P2OUT |= BIT2; }void AD7793_SCLK_CLR(){    P2OUT &=~ BIT2; } void AD7793_DIN_SET(){    P1OUT |= BIT6;}void AD7793_DIN_CLR(){    P1OUT &=~ BIT6;}unsigned int AD7793_DOUT_GET(){    unsigned int i;    if(P1IN & BIT7)      i = 1;    else      i = 0;    return i;}2.2 向AD7793写入一个字节

void WriteToReg(unsigned char ByteData) //向AD7793写入一个字节{    unsigned char temp;    unsigned char i;    AD7793_CS_CLR();    AD7793_SCLK_SET();    temp=0x80;    for(i=0;i<8;i++)    {        if((temp & ByteData)==0)        {            AD7793_DIN_CLR();        }        else        {            AD7793_DIN_SET();        }        AD7793_SCLK_CLR();        Delay();        AD7793_SCLK_SET();        Delay();        temp=temp>>1;    }    AD7793_CS_SET();}2.3 复位AD7793

void AD7793_Reset(void)//AD7793复位{    P1DIR |= BIT6;          P2DIR |= BIT2;    P1DIR &=~ BIT7;        unsigned int ResetTime;    ResetTime = 32;    AD7793_SCLK_SET();    AD7793_CS_CLR();    AD7793_DIN_SET();    while(ResetTime--)    {        Delay();        AD7793_SCLK_CLR();        Delay();        AD7793_SCLK_SET();    }    AD7793_CS_SET();}2.4 读取AD7793

unsigned char AD7793_ReadStatusRegister(void) //读取7793的状态寄存器{    unsigned char j;    unsigned char temp;    WriteToReg(0x40);    AD7793_DIN_SET();    AD7793_CS_CLR();    temp=0;    for(j=0; j<8; j++)    {        AD7793_SCLK_CLR();        if(AD7793_DOUT_GET()==0)        {            temp=temp<<1;        }        else        {            temp=temp<<1;            temp=temp+0x01;        }        Delay();        AD7793_SCLK_SET();        Delay();    }    AD7793_CS_SET();    return temp;}2.5 配置相关寄存器

void Ad7793_WriteModeRegister(unsigned char ModeRegisterH,unsigned char ModeRegisterL)//配置模式寄存器{    WriteToReg(0x08);    WriteToReg(ModeRegisterH);    WriteToReg(ModeRegisterL);}void Ad7793_WriteConfigRegister(unsigned char ConfigRegisterH,unsigned char ConfigRegisterL)//配置配置寄存器{    WriteToReg(0x10);    WriteToReg(ConfigRegisterH);    WriteToReg(ConfigRegisterL);}void Ad7793_WriteIORegister(unsigned char IORegister)//配置IO寄存器{    WriteToReg(0x28);    WriteToReg(IORegister);}2.6 读取AD7793数据寄存器

long AD7793_ReadDataRegister(void){union{    unsigned char chardata[3];    unsigned long longdata;}AD7793Result;    unsigned char i,j;    unsigned char temp;    temp=AD7793_ReadStatusRegister();    while((temp&0x80)==0x80)    {        temp=AD7793_ReadStatusRegister();    }    WriteToReg(0x58);    AD7793_DIN_SET();    AD7793_CS_CLR();    for(i=0; i<3; i++)    {        for(j=0; j<8; j++)        {            AD7793_SCLK_CLR();            if(AD7793_DOUT_GET()==0)            {                temp=temp<<1;            }            else            {                temp=temp<<1;                temp=temp+0x01;            }        Delay();        AD7793_SCLK_SET();        Delay();        }        AD7793Result.chardata[3-i]=temp;    }    AD7793_CS_SET();    AD7793Result.longdata=AD7793Result.longdata>>8;    return AD7793Result.longdata;}2.7 初始化AD7793

void Init_AD7793(void)//AD7793的初始化{    AD7793_CS_SET();    AD7793_Reset();    Ad7793_WriteModeRegister(0x00,0x0F);//连续转换    Ad7793_WriteConfigRegister(0x03,0x10);//292.5mv，1.65V偏压    Ad7793_WriteIORegister(0x0E);}