read incoming serial data as a string?

prismspecs

I have an Arduino program that is sending data to Processing via serial. It is meant to send a heads up message based on what kind of data is to follow. For example, when I want the Arduino to pipe some image data via serial, the message begins with ">IMG:". So I'd like to test for that string, then do something with the array of numbers that follow.

  if ( port.available() > 0) {  // If data is available,
    //val = port.read();         // read it and store it in val

    String test[] = {
      "","","","",""
    };

    for (int i = 0; i < test.length; i++) {
      test[i] = str(char(port.read()));
    }
    println(test);
    if(test == "> I M G :") {
      println("yup");
    }

I can never figure out how to make Processing play nice with strings. I just want to take in the first 4 chars and see if combined they form ">IMG:"

Also, if the Arduino is sending serial data as HEX, is there anything special I need to do when reading via Processing to make sure it safely converts to a usable int of the same value?

GoToLoop

http://processing.org/reference/String_equals_.html

prismspecs

Hmm no dice. Even though it is clearly printing "> I M G :" in the console, it isn't passing the IF statement

  if (port.available() > 0) {
    String test[] = {
      "", "", "", "", ""
    };

    for (int i = 0; i < test.length; i++) {
      test[i] = str(char(port.read()));
    }

    println(test);

    if(test.equals("> I M G :") == true) {
      println("yup");
    }
  }

GoToLoop

Perhaps trim() might help that out: http://processing.org/reference/trim_.html

PhiLho

Yes, most people having problems with equality of strings coming from serial solve them with trim(), because there can be extra spaces or newline chars.