How can I split a string into multiple parts?

Question

I currently gather a string via bluetooth to my arduino and the string only has 5 different letters. "HELLO". I now wish to store these individual letters in a string on their own. Right now i have this code:

First I create a single string:

String readString;

Then I read my BTLEserial which is where I get the value that is being sent to the arduino and i store it in my string:

char c = BTLEserial.read();
readString += c;

readString now has the value "HELLO". Now i want to split it and what I have tried is to do it like this:

String stringOne = readString.substring (0,1); //H
String stringTwo = readString.substring (1,2); //E
String stringThree = readString.substring (2,3); //L
String stringFour = readString.substring (3,4); //L
String stringFive = readString.substring (4,5); //O

But with this i do not get the correct values in each string.

Appreciate every help I can get! :)

Answer 1

An array is 0 indexed, which means that number 5 is out of index. "Hello" should be index valued 0-4 and not 0-5.

Here is a better code to try out:

void setup() {
    Serial.begin(9600);
}

void loop() {

String recivedMessage = "";

// Read
while (Serial.available())
{
    recivedMessage += Serial.read();
}

// Print debug
Serial.print("recivedMessage: ");
Serial.println(recivedMessage);


//// Uncomment the row under if you are not sure that the splitting is working
// recivedMessage = "Hello";

// Split
char first  = recivedMessage.substring(0, 1)[0];    // H
char second = recivedMessage.substring(1, 2)[0];    // E
char third  = recivedMessage.substring(2, 3)[0];    // L
char forth  = recivedMessage.substring(3, 4)[0];    // L
char fifth  = recivedMessage.substring(4)[0];       // 0

// Print debug
Serial.print("Cut message: ");
Serial.println(first);
Serial.println(second);
Serial.println(third);
Serial.println(forth);
Serial.println(fifth);

}

Answer 2

I think it would be easier if you used a char array. Here's some sample code.

char recievedData[100]
int numChars = 0
//Now we are in the receiving loop
recievedData[numChars] = BLTEserial.read()
numChars++

Now that you have a character array with all of the members, you can simply use the numChars variable to figure out how much you got from the serial buffer (for example, using it as the upper limit for a for loop).

Answer 3

String are the not the recommended way to use with Arduino although try using single parameter instead of two like substring(1) and let me know

char data[5];
for(int i=0;i <5 ;i++)
{
 data[i]=Serial.read();
}
char data1=data[0];
char data2=data[1];

so on and so forth ..