Conversione float to string

International Italiano Generale
3

Bonjour,

I'm using the following function to convert a float to a string:

String ftoa(float number, uint8_t precision, uint8_t size) {
  // Based on mem,  16.07.2008
  // http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num = 1207226548/6#6

  // prints val with number of decimal places determine by precision
  // precision is a number from 0 to 6 indicating the desired decimial places
  // example: printDouble(3.1415, 2); // prints 3.14 (two decimal places)

  // Added rounding, size and overflow #
  // ftoa(343.1453, 2, 10) -> "    343.15"
  // ftoa(343.1453, 4,  7) -> "#      "
  // avenue33, April 10th, 2010

  String s = "";

  // Negative 
  if (number < 0.0)  {
    s = "-";
    number = -number;
  }

  double rounding = 0.5;
  for (uint8_t i = 0; i < precision; ++i)    rounding /= 10.0;

  number += rounding;
  s += String(uint16_t(number));  // prints the integer part

  if(precision > 0) {
    s += ".";                // prints the decimal point
    uint32_t frac;
    uint32_t mult = 1;
    uint8_t padding = precision -1;
    while(precision--)     mult *= 10;

    frac = (number - uint16_t(number)) * mult;

    uint32_t frac1 = frac;
    while(frac1 /= 10)    padding--;
    while(padding--)      s += "0";

    s += String(frac,DEC) ;  // prints the fractional part
  }

  if (size>0)                // checks size
    if (s.length()>size)        return("#");
    else while(s.length()<size) s = " "+s;

  return s;
}

Enjoy!