Hi All,
I'm getting some weird results with my code, I'm trying to change a received string to a unsigned long, depending on the string received, I get different results, my code below

Serial.println("From the trigger");
Serial.println(str);
unsigned long B = atol(str.c_str());
unsigned long A = (long) strtol(str.c_str(),NULL,0);
Serial.println("this is A");
Serial.println(A);
Serial.println("this is B");
Serial.println(A);
WorkingString= String(A);
Serial.println("working string");
Serial.println(WorkingString);
Serial.println("and A");
Serial.println(A, HEX);
When I get a "working" value like 384311219 , the conversion is correct, but for something like 2291061678, the conversion becomes 2147483647
Any help would be appreciated please
Serial output below
From the trigger
2291061678
this is A
2147483647 *incorrect conversion*
this is B
2147483647 *incorrect conversion*
working string
2147483647
and A
7FFFFFFF
7FFFFFFF
From the trigger
384311219
this is A
384311219 *correct conversion*
this is B
384311219 *correct conversion*
working string
384311219
and A
16E81FB3
16E81FB3
//long long B = atol(str.c_str());
unsigned long A = (long) strtol(str.c_str(),NULL,0);
Serial.println("this is A");
Serial.println(A);
Serial.println("this is B");
Serial.println(B);
I get the same, by the way it a Arduino pro mini
From the trigger
2291061678
this is A
2147483647
this is B
2147483647
working string
2147483647
and A
7FFFFFFF
7FFFFFFF
              
unsigned long A = (long) strtol(str.c_str(),NULL,0);
Why not use B but some function call which we can't see?

Why cast the damn thing to a singed int again?

Why not use a real null pointer 'nullptr'?
Serial.println("this is B");
Serial.println(A);
Why print A if you tell it's B?
Questions questions questions...
              
i tried this
unsigned long A = atol(str.c_str());
it is still converting till 2,147,483,647 which is the upper limit of long data type. so just declaring a unsigned would only change the data type of the number stored in A but would not convert a number which is larger than

2,147,483,647.
still looking for converting a string with digits greater than 2,147,483,647 and less than 4,294,967,295 to unsigned long which actually increases the capacity of a number per say.
my observation thought i should share.