147 lines
3.2 KiB
C
147 lines
3.2 KiB
C
#include "max31865.h"
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/***********************************************
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调用方式：MAX31865_Init()
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返回值：
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SDO ---> PC10
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CS ---> PC12
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SCLK ---> PC9
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SDI ---> PC11
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DRDY ---> PC13
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函数说明：MAX31865 初始化,软件模拟
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************************************************/
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void MAX31865_Init(void)
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{
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GPIO_InitTypeDef GPIO_InitStructure ;
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RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC|RCC_APB2Periph_GPIOB|RCC_APB2Periph_GPIOA,ENABLE);
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GPIO_InitStructure.GPIO_Pin = MAX31865_CS|MAX31865_SCLK|MAX31865_SDI;
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GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
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GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
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GPIO_Init(MAX31865_CONTROL_PORT,&GPIO_InitStructure);
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GPIO_InitStructure.GPIO_Pin = MAX31865_SDO|MAX31865_DRDY;
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GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
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GPIO_Init(MAX31865_CONTROL_PORT,&GPIO_InitStructure);
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MAX31865_CS_SET;
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MAX31865_SCLK_SET;
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}
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/***********************************************
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调用方式：MAX31865_Write()
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返回值：
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函数说明：MAX31865 写寄存器,addr:寄存器地址,data:数据
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************************************************/
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void MAX31865_Write(unsigned char addr, unsigned char data)
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{
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unsigned char i;
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MAX31865_CS_CLR;
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for(i=0;i<8;i++) //写地址
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{
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MAX31865_SCLK_CLR;
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if(addr&0x80) MAX31865_SDI_SET;
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else MAX31865_SDI_CLR;
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MAX31865_SCLK_SET;
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addr<<=1;
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}
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for(i=0;i<8;i++) //写数据
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{
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MAX31865_SCLK_CLR;
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if(data&0x80) MAX31865_SDI_SET;
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else MAX31865_SDI_CLR;
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MAX31865_SCLK_SET;
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data<<=1;
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}
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MAX31865_CS_SET;
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}
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/***********************************************
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调用方式：MAX31865_Read()
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返回值： data
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函数说明：MAX31865 读寄存器 ,addr:寄存器地址
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************************************************/
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unsigned char MAX31865_Read(unsigned char addr)
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{
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unsigned char i;
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unsigned char data=0;
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MAX31865_CS_CLR;
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for(i=0;i<8;i++) //写地址
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{
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MAX31865_SCLK_CLR;
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if(addr&0x80) MAX31865_SDI_SET;
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else MAX31865_SDI_CLR;
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MAX31865_SCLK_SET;
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addr<<=1;
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}
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for(i=0;i<8;i++) //读数据
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{
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MAX31865_SCLK_CLR;
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data<<=1;
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MAX31865_SCLK_SET;
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if(MAX31865_SDO_READ) data|=0x01;
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else data|=0x00;
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}
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MAX31865_CS_SET;
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return data;
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}
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/***********************************************
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调用方式：MAX31865_Cfg()
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返回值：
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函数说明：MAX31865 配置
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************************************************/
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void MAX31865_Cfg(void)
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{
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//BIAS ON,自动，4线，50HZ 根据文件修改四线还是三线
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MAX31865_Write(0x80, 0xC3);
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}
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/***********************************************
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调用方式：MAX31865_GetTemp()
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返回值：
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函数说明：MAX31865 获取温度
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************************************************/
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float MAX31865_GetTemp(void)
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{
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unsigned int data;
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float Rt;
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float Rt0 = 100; //PT100
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float Z1,Z2,Z3,Z4,temp;
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float a = 3.9083e-3;
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float b = -5.775e-7;
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float rpoly;
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// MAX31865_Write(0x80, 0xD3);
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data=MAX31865_Read(0x01)<<8;
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data|=MAX31865_Read(0x02);
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data>>=1; //去掉Fault位
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Rt=(float)data/32768.0*RREF;
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Z1 = -a;
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Z2 = a*a-4*b;
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Z3 = 4*b/Rt0;
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Z4 = 2*b;
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temp = Z2+Z3*Rt;
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temp = (sqrt(temp)+Z1)/Z4;
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if(temp>=0){
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return temp;
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}
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rpoly = Rt;
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temp = -242.02;
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temp += 2.2228 * rpoly;
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rpoly *= Rt; // square
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temp += 2.5859e-3 * rpoly;
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rpoly *= Rt; // ^3
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temp -= 4.8260e-6 * rpoly;
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rpoly *= Rt; // ^4
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temp -= 2.8183e-8 * rpoly;
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rpoly *= Rt; // ^5
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temp += 1.5243e-10 * rpoly;
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return temp;
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}
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