基于MSP430的AD7745的模拟IIC驱动

#include <msp430.h> #include <math.h> #include <stdlib.h> #include <stdio.h> #include <string.h> #define CPU_F ((double)1500000) #define delayus(x) __delay_cycles((long)(CPU_F*(double)x/1000000.0)) #define delayms(x) __delay_cycles((long)(CPU_F*(double)x/1000.0)) #define OP_READ 0x91 //器件地址读 #define OP_WRITE 0x90 //器件地址写 #define uchar unsigned char #define uint unsigned int #define SDA_OUT P1DIR |= BIT6 #define SDA_IN P1DIR &= ~BIT6 #define SCL_OUT P1DIR |= BIT7 #define SCL_IN P1DIR &= ~BIT7 #define SDA_H P1OUT |= BIT6 //#define SDA_H P1DIR &= ~BIT6 #define SDA_L P1OUT &= ~BIT6 //#define SDA_L P1DIR |= BIT6; P1OUT &= ~BIT6 #define SCL_H P1OUT |= BIT7 #define SCL_L P1OUT &= ~BIT7 //********************************* //定义常量 //********************************* #define FULL_SCALE 0xFFFFFF #define SEMI_SCALE 0x800000 //#define SEMI_SCALE 0x000000 #define CAPDAC_UNIT 0.133858 // 17pF/(2^7-1) CAPDACA 7位有效 #define DataNumber 8 // 电容数据平均 //********************************* //定义变量 //********************************* unsigned char in_buff[3]; // the data buffer unsigned char out_buff[6] = {0x80,0x00,0x0B,0x39}; // config the data buffer unsigned char offset_buf[2] = {0x8A,0xD0}; long int CDC_Register_data; // CDC寄存器数据 float CAPDAC; // 偏移的电容值 float CDC_Capacitance,CDC_Capacitance1,CDC_Capacitance2; // 测量电容值 int cap_convert_over = 0; unsigned char Capdac_Parameter = 30; unsigned char capdac_buf[5] = {0x80,0x00,0x0B,0x39}; //原配置{0x80,0x00,0x08,0x39}; unsigned char capdac_offset; long capdac_register_data; unsigned char Int_dec = 0; unsigned char i = 0; float Accumulator = 0; float Impedance_temp; float Capacitance; float Max=0; float Min=0; unsigned char MaxFlag,MinFlag,Exchange; float DataArr[DataNumber]; // 电容数据存储 int InitFlag=0; unsigned char ucLen =0; char Data[25]={0}; unsigned char k=0; void write_byte(uint data); /**************************** Initialize System Clock ************************/ //Configuration: F_DCO = 24MHz, F_MCLK = 24MHz, F_SMCLK = 6MHz, F_ACLK = 750kHz void InitCLK(void) { //password for CS CSCTL0 = CSKEY; // Set max. DCO setting. Set DC0 =24MHz CSCTL1 |= DCORSEL + DCOFSEL0 + DCOFSEL1; // set ACLK = MCLK = DCO CSCTL2 = SELA_3 + SELS_3 + SELM_3; // set dividers: MCLK: 1, SMCLK: 4, ACLK: 32 CSCTL3 = DIVA__32 + DIVS__4 + DIVM_4; } void start() { SCL_OUT; SDA_OUT; SDA_H; delayms(1); SCL_H; delayms(1); SDA_L; delayms(1); SCL_L; delayms(1); } void stop() { SDA_OUT; SCL_OUT; SDA_L; delayms(1); SCL_H; delayms(1); SDA_H; delayms(1); } void Ack() { SDA_OUT; SCL_OUT; SCL_L; SDA_L; delayms(1); SCL_H; delayms(1); SCL_L; } void NAck() { SDA_OUT; SCL_OUT; SCL_L; SDA_H; delayus(2); SCL_H; delayus(2); SCL_L; } unsigned int WAck() { SDA_H; SDA_IN; SCL_H; while(P1IN & BIT6) { } SCL_L; delayms(1); return 0; } //mcu读取数据 uchar read_byte() { uchar i,read_data; SDA_OUT; SCL_L; SDA_H; for(i = 0;i<8;i++) { SDA_H; delayus(2); SCL_H; SDA_IN; delayus(2); read_data <<= 1; if(P1IN & BIT6) read_data |= 0x01; SDA_OUT; SCL_L; } delayms(5); return(read_data); } void write_byte(uint data) { uchar i; SCL_OUT; SDA_OUT; for(i = 0;i<8;i++) { if(data & 0x80) SDA_H; else SDA_L; delayms(1); SCL_H; delayms(1); SCL_L; delayms(1); data = data << 1; } // SCL_L; // delayus(2); delayms(5); } //向指定地址写数据 void write_dat(uchar addr,uchar write_data) { start(); write_byte(OP_WRITE); WAck(); write_byte(addr); WAck(); write_byte(write_data); WAck(); stop(); delayus(1000); } //从指定地址读数据 uchar read_random(uint random_addr) { uchar i; start(); write_byte(OP_WRITE); WAck(); write_byte(random_addr); WAck(); start(); write_byte(OP_READ); WAck(); i = read_byte(); stop(); return i; } void Init_AD7745() { start(); write_byte(0X09); WAck(); write_byte(0xBF); delayus(500); WAck(); stop(); } void EEPROM_WriteArray (unsigned char dest_addr, unsigned char* src_addr, unsigned char len) { unsigned char i; start(); write_byte(OP_WRITE); WAck(); write_byte(dest_addr); WAck(); for( i = 0; i < len; i++ ) { write_byte(src_addr[i]); WAck(); } stop(); delayus(1000); } void EEPROM_ReadArray (unsigned char* dest_addr, unsigned char src_addr, unsigned char len) { uchar i; start(); write_byte(OP_WRITE); WAck(); write_byte(src_addr); WAck(); start(); write_byte(OP_READ); WAck(); for( i = 0; i < len; i++ ) { dest_addr[i] = read_byte(); if(i!=len-1) Ack(); else NAck(); } stop(); } void Capdacsetup(void) { EEPROM_WriteArray(0x0D, offset_buf, sizeof(offset_buf)); // OFFSET寄存器初始化 Capdac_Parameter = 127; capdac_offset = Capdac_Parameter; out_buff[4] = 0x80+capdac_offset; //CAPDACA is set to capdac_offset out_buff[5] = 0x80; //CAPDACB is set to 0 CAPDAC = (float)(capdac_offset*CAPDAC_UNIT); //CAPDAC只会取4值，即4.25，8.5，12.75，17 EEPROM_WriteArray(0x07, out_buff, sizeof(out_buff)); // data collect memset(DataArr,0,sizeof(float)*DataNumber); } void ReadData(void) { EEPROM_ReadArray(in_buff, 0x01, sizeof(in_buff)); // read the data register CDC_Register_data = 0; CDC_Register_data = in_buff[0]; CDC_Register_data <<= 8; CDC_Register_data += in_buff[1]; CDC_Register_data <<= 8; CDC_Register_data += in_buff[2]; CDC_Register_data &= 0x00ffffff; CDC_Capacitance2 = (float)(FULL_SCALE-SEMI_SCALE); if(CDC_Register_data>= SEMI_SCALE) { CDC_Capacitance1 = (float)(CDC_Register_data-SEMI_SCALE); CDC_Capacitance = 4.096 * (CDC_Capacitance1/CDC_Capacitance2); } else { CDC_Capacitance1 = (float)(SEMI_SCALE-CDC_Register_data); CDC_Capacitance = -4.096 * (CDC_Capacitance1/CDC_Capacitance2); } CDC_Capacitance = CAPDAC+CDC_Capacitance; DataArr[Int_dec++]=CDC_Capacitance; if(Int_dec==DataNumber) Int_dec=0; /////////////////////////////////////////////////////////// for(i=0;i<DataNumber;i++) // DataNumber个数据求和 { Accumulator +=DataArr[i]; } Capacitance = Accumulator/DataNumber; Accumulator = 0; } int main( void ) { // Stop watchdog timer to prevent time out reset WDTCTL = WDTPW + WDTHOLD; uchar data; InitCLK(); ; while(1) { data = read_random(0x00); data = data + 1; } }