convert HEX string to Decimal in arduino

Question

i have an Hex String like this : \"0005607947\" and want to convert it to Decimal number , i test it on this site and it correctly convert to decimal number and answer is :

Answer 1

Drop all that code, and just use 'strtol' from the standard library.

 #include <stdlib.h>
 long strtol (const char *__nptr, char **__endptr, int __base)

For your use:

long decimal_answer = strtol("0005607947", NULL, 16);

Answer 2

You are trying to store the value 90208583 in an int. Arduino has a 2 byte int size meaning that the largest number you can store is 2^16-1 (65535). You have a couple of options:

1. Use an unsigned int
   • min number: 0
   • max number: 4,294,967,295
   • cons: can only be used for positive numbers
2. Use a long int
   • min number: -2,147,483,648
   • max number: 2,147,483,647