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1  Using Arduino / Programming Questions / Re: Programing question on: January 16, 2013, 01:49:23 pm
Thank you Arrch.
2  Using Arduino / Programming Questions / Programing question on: January 15, 2013, 12:56:23 pm
Hello, I’m trying to figure out a few things with Arduino hooked up to Parallax reader but got stuck on some code. Tried to look at Arduino help/reference doesn’t give me much hope. I guess this is completely beginner inexperience not to say lack of knowledge and if anyone can spare a few minutes to clarify that for me, I would be grateful.
What is the difference between the following variable declarations:

First question:

---------------------------------------
String  keyCode;
String  accessList[NumberOfKeys];
char    code[10];
--------------------------------------
I can see two arrays have been allocated but what is basically confusing me is string and char. What is the difference between them?

Second question:
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keyCode = code;
       keyCode = keyCode.substring(0,10);
-------------------------------------
What is happening here, keyCode variable has been assigned code value, why we need the next line of code with keyCode.substring(0,10)?


Thank you very much in advance,
Tom
3  Community / Exhibition / Gallery / Re: PRFID Mod Parallax RFID reader on: January 13, 2013, 05:20:02 am
Hello,

Pretty interesting topic and since I am a complete beginner in programming, got stuck understanding your code as follows:

1.   Why this line is necessary, some kind of data conversion?
keyCode = keyCode.substring(0,10);

2.   What will happen here, if the  first if statement is correct, the code will execute and else statement will be skipped, am I right?  Actually what is the purpose of the first statement.

if((keyCode == Master) && (programmingMode == false))
       {programmingMode = true;
        digitalWrite(PROGRAMMING_LIGHT,HIGH);
      }
       else
       {if(programmingMode == false)


Thanks in advace, Tom
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