Convert a Bitstring into an integer value

Question

I have got a String filled up with 0 and 1 and would like to get an Integer out of it:

String bitString = ""; 
int Number;
int tmp;
bitString = "";
 for (i=1;i<=10;i++)
 {
 tmp= analogRead (A0);
 bitString += tmp % 2;
 delay(50);
 }
// now bitString contains for example "10100110" 
// Number = bitstring to int <-------------
// In the end I want that the variable Number contains the integer 166

• Craig: What is the question? What do you expect this code to do and what is it doing? What else have you tried?
• kimliv: @Craig I eddited the question. For example If the bitString contains a "10100110" I want the programm to save it as the decimal 166 in the int variable.
• Craig: Do you need the string? You could create the integer representation directly.
• kimliv: @Craig i would also like to print out the bitstring

Answer 1

If you only need the string for printing you can store value in an integer and then use the Serial.print(number,BIN) function to format the output as a binary value. Appending integers to strings is a potentially costly operation both in performance and memory usage.

int Number = 0;
int tmp;
for (int i=9;i>=0;i--) {
 tmp = analogRead (A0);
 Number += (tmp % 2) << i;
 delay(50);
}
Serial.print(Number, BIN);

• kimliv: Yes your solution looks more efficient! and does the work

Answer 2

Check out strtoul()

It should work something like this:

unsigned long result = strtoul(bitstring.c_str(), NULL, 2);

Now you have a long variable which can be converted into an int if needed.

• Doowybbob: @kimliv Did you add .c_str() to the end of bitstring as Peter pointed out above? c_str() should return a const char*.
• kimliv: it is working that way!