int x_int=2100;
float x_max-30;
float x_min= -30;
int bits=12;
float uint_to_float(int x_int, float x_min, float x_max, int bits)
 {
   /// converts unsigned int to float, given range and number of bits ///
   float span = x_max - x_min;//计算差值
   float offset = x_min;
   return (((float)x_int)*span/((float)((1<<bits)-1)) + offset);
   }
return=????










