STC15系列内部SPI驱动24位ADC芯片ADS1256

#include "C:\Keil\C51\INC\STC\STC15F2K60S2.H" #include "ads1256.h" void sendStr(unsigned char *s); void sendChar(unsigned char ch); unsigned char SPI_SendByte(unsigned char SPI_SendData); //-----------------------------------------------------------------// // 功 能：延时 // 入口参数: 延时时间 delay * us // 出口参数: / // 全局变量: / // 备 注: //-----------------------------------------------------------------// void Delay(unsigned int dal) { unsigned int i; for(i = 0;i < dal;i ++); } //-----------------------------------------------------------------// // 功 能：ADS1256 写数据 // 入口参数: / // 出口参数: / // 全局变量: / // 备 注: 向ADS1256中地址为regaddr的寄存器写入一个字节databyte //-----------------------------------------------------------------// void ADS1256WREG(unsigned char regaddr,unsigned char databyte) { ADS_CS = 0; while(ADS_DRDY);//当ADS1256_DRDY为低时才能写寄存器 //向寄存器写入数据地址 SPI_SendByte(ADS1256_CMD_WREG | (regaddr & 0xF)); //写入数据的个数n-1 SPI_SendByte(0); //向regaddr地址指向的寄存器写入数据databyte SPI_SendByte(databyte); ADS_CS = 1; } //-----------------------------------------------------------------// // 功 能： // 入口参数: / // 出口参数: / // 全局变量: / // 备 注: //-----------------------------------------------------------------// unsigned long ADS1256ReadData(void) { unsigned char i=0; unsigned long sum=0; unsigned long r=0; ADS_CS = 0; while(ADS_DRDY); //当ADS1256_DRDY为低时才能写寄存器 SPI_SendByte(ADS1256_CMD_SYNC); SPI_SendByte(ADS1256_CMD_WAKEUP); SPI_SendByte(ADS1256_CMD_RDATA); ADS_SCLK = 0; for(i=0;i<3;i++) { sum = sum << 8; r = SPI_SendByte(0); sum |= r; } ADS_CS = 1; return sum; } //-----------------------------------------------------------------// // 功 能：ADS1256初始化子程序 // 入口参数: / // 出口参数: / // 全局变量: / // 备 注: / //-----------------------------------------------------------------// void ADS1256_Init(void) { ADS_CS = 0; // 发送复位命令 // ADS_RESET = 0; // Delay(DELAY_10ms); ADS_REST = 1; ADS1256WREG(ADS1256_STATUS,0x04); // 高位在前、校准、使用缓冲 ADS1256WREG(ADS1256_MUX,0x08); // 初始化端口A0为‘+’，AINCOM位‘-’ ADS1256WREG(ADS1256_ADCON,0x00); // 放大倍数1 ADS1256WREG(ADS1256_DRATE,ADS1256_DRATE_5SPS); // 数据5sps ADS1256WREG(ADS1256_IO,0x00); // IO状态输入 ADS_CS = 1; } //-----------------------------------------------------------------// // 功 能：读取ADS1256单路数据 // 入口参数: / // 出口参数: / // 全局变量: / // 备 注: / //-----------------------------------------------------------------// void ADS_sum(unsigned char road) { unsigned long results=0; unsigned long Result_sum=0; unsigned long fVoltage; unsigned char buf[12],i,rod; ADS1256WREG(ADS1256_MUX,road); //设置通道 // SPI_SendByte(ADS1256_CMD_SELFCAL); //偏移和增益自动校准 // SPI_SendByte(ADS1256_CMD_SYSOCAL); //系统失调校准 // SPI_SendByte(ADS1256_CMD_SYSGCAL); //系统增益校准 if(road/16 == 0) //根据手册P21 本次读取的数据是上一次转换的值 rod = (7 + 0x30); //进行通道-1计算 else rod = ((road/16 + 0x30) -1); sendStr("第"); sendChar(rod); sendStr("路："); results = ADS1256ReadData();//读取AD值，返回24位数据。 ///////发送AD转换后实际电压值到串口,因为计算精度问题，电压值有小的偏差///////// Result_sum = results >> 1; if(Result_sum<0x400000) //测得电压值为正的情况 { fVoltage=Result_sum*119; //119=2*2.5/2^22*100000000 2.5为基准电压 1000000000为为了计算的准确性转换为整形计算 buf[0]=(unsigned char)(fVoltage/100000000); buf[0]=buf[0]+0x30; buf[1]='.'; buf[2]=(unsigned char)((fVoltage%100000000)/10000000); buf[2]=buf[2]+0x30; buf[3]=(unsigned char)((fVoltage%10000000)/1000000); buf[3]=buf[3]+0x30; buf[4]=(unsigned char)(fVoltage%1000000/100000); buf[4]=buf[4]+0x30; buf[5]=(unsigned char)(fVoltage%100000/10000); buf[5]=buf[5]+0x30; buf[6]=(unsigned char)(fVoltage%10000/1000); buf[6]=buf[6]+0x30; buf[7]=(unsigned char)(fVoltage%1000/100); buf[7]=buf[7]+0x30; buf[8]=(unsigned char)(fVoltage%100/10); buf[8]=buf[8]+0x30; buf[9]=(unsigned char)(fVoltage%10); buf[9]=buf[9]+0x30; buf[10]='V'; //V buf[11]=0x20; } else //测得电压值为负的情况 { //buf[0]='-'; //取‘-’号 Result_sum=0xfffff-Result_sum; //取反运算 fVoltage=Result_sum*119; //119=2*2.5/2^22*100000000 2.5为基准电压 1000000000为为了计算的准确性转换为整形计算 buf[0]=(unsigned char)(fVoltage/100000000); buf[0]=buf[0]+0x30; buf[1]='.'; buf[2]=(unsigned char)((fVoltage%100000000)/10000000); buf[2]=buf[2]+0x30; buf[3]=(unsigned char)((fVoltage%10000000)/1000000); buf[3]=buf[3]+0x30; buf[4]=(unsigned char)(fVoltage%1000000/100000); buf[4]=buf[4]+0x30; buf[5]=(unsigned char)(fVoltage%100000/10000); buf[5]=buf[5]+0x30; buf[6]=(unsigned char)(fVoltage%10000/1000); buf[6]=buf[6]+0x30; buf[7]=(unsigned char)(fVoltage%1000/100); buf[7]=buf[7]+0x30; buf[8]=(unsigned char)(fVoltage%100/10); buf[8]=buf[8]+0x30; buf[9]=(unsigned char)(fVoltage%10); buf[9]=buf[9]+0x30; buf[10]='V'; //V buf[11]='-'; } i=0; while(i<12) { sendChar(buf[i]); i++; } } /*********发送AD转换后的十六进制码到串口，使用时打开*************/ /* void ADS_sum(unsigned char road) { unsigned long results=0; results = ADS1256ReadData();//读取AD值，返回24位数据。 sendChar((unsigned long)(results >> 16) & 0x0000ff); //发送最高位 sendChar((unsigned long)(results >> 8) & 0x0000ff); //发送中间位 sendChar((unsigned long)results & 0x0000ff); //发送低位 } */