Convert Hex to Decimal

I have a BLE buffer which contain 4 Hex digits like:


I can manually convert 0005C47B to decimal =377979

How can I do this in code going from hex buffer to decimal

@Athnetix, one way uses the sscanf() C++ function:

You can use sscanf() to parse out each HEX value as an unsigned integer then sum them in their corrected bit order. For example, if 00:05:C4:7B is parsed to variables a,b,c,d then the order-corrected sum of the values is:

unsigned value = a<<24 + b<<16 + c<<8 + d; where “<<X” is “left shift by X bits” which is the same as multiplying by 2 to the X power.


Thanks peekay that works great. The part that was getting me was how best to put the bytes back together.

Just for completeness, if you had a valid HEX string already you could also use strtol(s, NULL, 16) to convert that into a numeric value.