How to convert a String to a Byte[] ?

Projects Programming
1

Im having trouble converting a String containing 7 numbers into a a byte[]
Whats happening is the numbers from the String are not translating through to the "real" number value

For instance, String value of 1 becomes 49, 2 becomes 50, 3 becomes 51, etc.

Obviously I want a String with a value of "1" to equal a byte value 1 not 49...

Here is my code

String days = "111111"
byte buff[days.length()];
char c;
for(int i=0;i<7;i++){
  c = days.charAt(i);
  buff[i] = byte(c);
  Serial.print(buff[i]); 
}

The output for is 49494949494949 instead of 1111111

How do I fix this!?
I know I must be missing a step here somewhere....

An answer plus a simple explanation would be fantastic!

2

Obviously I want a String with a value of "1" to equal a byte value 1 not 49...

Then, your expectations are unreasonable. The value of '1' IS 49.

What is it you intend to do with the byte array?

Here's a hint, though. '1' - '0' = 1.

3

...because ASCII value of "1" is not "1" but "49" - you must decrease 48

4 
String days = "111111"

for(int i=0;i<7;i++)

You have only six '1's in your String, but no semicolon after it.

5

Wow such a simple solution!
..just minus 48 from it...perfect.

"What is it you intend to do with the byte array?"
It represents the 7 days of the week as either 0 or 1...on or off...think scheduling...

"You have only six '1's in your String, but no semicolon after it."
yes, correct. 2 mistakes in my trying. This is just an extract of a much larger sketch (around 135Kb) hand typed
Lucky this html form isnt a C++ compiler.. :stuck_out_tongue:

6

..just minus 48 from it...perfect.

decimalVal = charVal - '0';

is much easier to remember.

7

It represents the 7 days of the week as either 0 or 1...on or off...think scheduling...

Why not think '0' and '1'? What is the benefit of converting the String to a series of 0s and 1s as opposed to '0's and '1's?