freescale单片机单精度浮点与16进制与ascii之间的转化

//—将单精度浮点转化成unsigned char数组，然后将unsigned char数组转化成ascii码字符串

float BallData[8] = {-8.925133};

unsigned char *f2char;

unsigned char ControlData[64];

void float2uchar2ascii(void)

{

unsigned char i = 0;

f2char = &BallData;//float to unsiged char[]

//8个floatd对应于32个unsigned char,所以f2char为32位

//f2char[32]={0xC10EDC58,0xC10EDC58,0xC10EDC58,0xC10EDC58,…,0xC10EDC58}

for(i=0;i<32;i++)

{

ControlData[2*i ] = f2char[i]/16+(f2char[i]/16>9?55:48);//unsigned char to ascii char

ControlData[2*i+1] = f2char[i]+(f2char[i]>9?55:48);

//本例中，f2char[0]=0xC1，要把它转化为ascii码字符串首先要得到高四位，然后得到低四位

//假如四位的值大于9，则应转化为字母a~f，不然应转化为0~9

//字母的应该在成果上+55，由于a的ascii码为65，基数为10，所以加55

//数字的应该在成果上+48，由于0的ascii码为48，基数为00，所以加48

}

}

//—将ascii码字符串转化成单精度浮点

unsigned char ControlData[64]={“C10EDC58”};

float BallData[8];

void asciistring2single(void)

{

unsigned char i=0,k=0;

unsigned char temp[4];

for(i=0;i<64;i++)

{

temp[i]=ControlData[i%4];

if(i%4==3)

{

BallData[k++]=(*((float*)temp));

}

}

}

//—将16进制与float之间的转化

union f_to_char

{

uchar chr[4];

float ft0;

} test;//界说一个union，直接对test.float操作，即从chr[4]中得到16进制的数组；反之亦然

test.ft0=3.14;//→chr[4]={0x40,0x48,0xF5,0xC3};