Add print(float) to save space (VS double).

Author: honnet

Diff for: cores/arduino/Print.cpp

@@ -129,6 +129,11 @@ size_t Print::print(unsigned long long n, int base)
   }
 }
 
+size_t Print::print(float n, int digits)
+{
+  return printFloat(n, digits);
+}
+
 size_t Print::print(double n, int digits)
 {
   return printFloat(n, digits);
@@ -221,6 +226,13 @@ size_t Print::println(unsigned long long num, int base)
   return n;
 }
 
+size_t Print::println(float num, int digits)
+{
+  size_t n = print(num, digits);
+  n += println();
+  return n;
+}
+
 size_t Print::println(double num, int digits)
 {
   size_t n = print(num, digits);
@@ -406,6 +418,58 @@ size_t Print::printULLNumber(unsigned long long n64, uint8_t base)
   return bytes;
 }
 
+size_t Print::printFloat(float number, uint8_t digits)
+{
+  size_t n = 0;
+
+  if (isnan(number)) {
+    return print("nan");
+  }
+  if (isinf(number)) {
+    return print("inf");
+  }
+  if (number > 4294967040.0) {
+    return print("ovf");  // constant determined empirically
+  }
+  if (number < -4294967040.0) {
+    return print("ovf");  // constant determined empirically
+  }
+
+  // Handle negative numbers
+  if (number < 0.0) {
+    n += print('-');
+    number = -number;
+  }
+
+  // Round correctly so that print(1.999, 2) prints as "2.00"
+  float rounding = 0.5;
+  for (uint8_t i = 0; i < digits; ++i) {
+    rounding /= 10.0;
+  }
+
+  number += rounding;
+
+  // Extract the integer part of the number and print it
+  unsigned long int_part = (unsigned long)number;
+  float remainder = number - (float)int_part;
+  n += print(int_part);
+
+  // Print the decimal point, but only if there are digits beyond
+  if (digits > 0) {
+    n += print('.');
+  }
+
+  // Extract digits from the remainder one at a time
+  while (digits-- > 0) {
+    remainder *= 10.0;
+    unsigned int toPrint = (unsigned int)remainder;
+    n += print(toPrint);
+    remainder -= toPrint;
+  }
+
+  return n;
+}
+
 size_t Print::printFloat(double number, uint8_t digits)
 {
   size_t n = 0;

Diff for: cores/arduino/Print.h

@@ -37,6 +37,7 @@ class Print {
     size_t printNumber(unsigned long, uint8_t);
     size_t printULLNumber(unsigned long long, uint8_t);
     size_t printFloat(double, uint8_t);
+    size_t printFloat(float, uint8_t);
   protected:
     void setWriteError(int err = 1)
     {
@@ -86,6 +87,7 @@ class Print {
     size_t print(unsigned long, int = DEC);
     size_t print(long long, int = DEC);
     size_t print(unsigned long long, int = DEC);
+    size_t print(float, int = 2);
     size_t print(double, int = 2);
     size_t print(const Printable &);
 
@@ -100,6 +102,7 @@ class Print {
     size_t println(unsigned long, int = DEC);
     size_t println(long long, int = DEC);
     size_t println(unsigned long long, int = DEC);
+    size_t println(float, int = 2);
     size_t println(double, int = 2);
     size_t println(const Printable &);
     size_t println(void);