native 16bit int and large floats fix

README.md

@@ -172,7 +172,7 @@ int length = sprintf(NULL, "Hello, world"); // length is set to 12
 | PRINTF_NTOA_BUFFER_SIZE            | 32        | ntoa (integer) conversion buffer size. This must be big enough to hold one converted numeric number _including_ leading zeros, normally 32 is a sufficient value. Created on the stack |
 | PRINTF_FTOA_BUFFER_SIZE            | 32        | ftoa (float) conversion buffer size. This must be big enough to hold one converted float number _including_ leading zeros, normally 32 is a sufficient value. Created on the stack |
 | PRINTF_DEFAULT_FLOAT_PRECISION     | 6         | Define the default floating point precision |
-| PRINTF_MAX_FLOAT                   | 1e9       | Define the largest suitable value to be printed with %f, before using exponential representation |
+| PRINTF_MAX_FLOAT                   | 1e9       | Define the largest suitable value to be printed with %f, before using exponential representation. Note that this should be set to be less than int32 max (2,147,483,647) to avoid issues |
 | PRINTF_DISABLE_SUPPORT_FLOAT       | undefined | Define this to disable floating point (%f) support |
 | PRINTF_DISABLE_SUPPORT_EXPONENTIAL | undefined | Define this to disable exponential floating point (%e) support |
 | PRINTF_DISABLE_SUPPORT_LONG_LONG   | undefined | Define this to disable long long (%ll) support |

printf.c

@@ -380,7 +380,7 @@ static size_t _ftoa(out_fct_type out, char* buffer, size_t idx, size_t maxlen, d
     prec--;
   }
 
-  int whole = (int)value;
+  int32_t whole = (int32_t)value;
   double tmp = (value - whole) * pow10[prec];
   unsigned long frac = (unsigned long)tmp;
   diff = tmp - frac;