UPLOAD THIS SKETCH TO ARDUINO:

// Demonstrate 2-way communication between

// Mac [OSX 10.6.4] running REALStudio 2010r3 and Arduino

// Demo requires this sketch be uploaded to Arduino

// and program entitled "twoway" to be run on the Mac side

// Written by: Ken Jenkins - August 2010 [No rights reserved]

const int ledPin = 13; // the pin that the LED is attached to

int incomingByte; // a variable to read incoming serial data into

void setup() {

  // initialize serial communication:
  Serial.begin(9600);
  // initialize the LED pin as an output:
  pinMode(ledPin, OUTPUT);

}

void loop() {

  // see if there's incoming serial data:
  if (Serial.available() > 0) {
    // read the oldest byte in the serial buffer:
    incomingByte = Serial.read();
    // if it's a capital H (ASCII 72), turn on the LED:
    if (incomingByte == 'H') {
      digitalWrite(ledPin, HIGH);
    } 
    // if it's an L (ASCII 76) turn off the LED:
    if (incomingByte == 'L') {
      digitalWrite(ledPin, LOW);
    }
  }
  // You can play with this delay, but without it as the
  // program stands now you will get more sync errors on
  // the Mac side

  delay(100);

  Serial.print("@:AA:BB:CC:DD:EE:FF:");

}

THIS IS THE REALSTUDIO CODE FOR THE MAC SIDE

I CAN'T FIGURE OUT HOW TO UPLOAD THE "PROJECT" AS A WHOLE SO IT CAN BE LOADED UNDER REALStudio HERE AND I CAN'T FIGURE OUT HOW TO LOAD THE SCREEN LAYOUT EITHER. SORRY.

Class TwoWaySerial

Inherits Application

Const kEditClear = "&Delete"

Const kFileQuit = "&Quit"

Const kFileQuitShortcut = ""

End Class

Class Main Inherits Window

Main.Close:

Sub Close()

   SerialCom.close
   quit

End Sub

Main.Open:

Sub Open()

    //Initialization
    //Set globals for record and field separators and
    //number of fields
    GB_recordseparator="@"
    GB_recordlength=20
    GB_fieldseparator=":"
    GB_fieldcount=6

    //Open a serial port
    If SerialCom.Open then
       //MsgBox "The serial port is open."
    Else
       MsgBox "The serial port could not be opened."
       quit
    End if

End Sub

Main Control SerialCom:

Sub DataAvailable()

    do
        // Attempt to process some data
        dim count as Integer = GB.process_packet( me.LookAhead )
        // If we have a full packet,then count will be >0
        if count > 0 then
           // Remove the data from the RB internal buffer
           call me.Read( count )
        else
           // We didn't process an entire packet, so we want to bail out
           exit
        end if
     loop until me.BytesAvailable <= 0

End Sub

End Class

Module GB

GB.process_packet:

Function process_packet(data as string) As integer

    //Process Packet
    dim packet as string
    dim ldata as integer
    static sync_error_count as integer
    static good_count as integer
    dim hexstring as string
    dim fieldarray() as string
    dim i as integer

    ldata=len(data)

    //Wait until you have a complete packet
    if ldata >=GB_recordlength then
       packet=left(data,ldata)
       //Check that the record separator is the first byte in the packet and that the //packet is the expected length .... else reject it
       if left(packet,1)=GB_recordseparator and ldata=GB_recordlength then
       //This is where you do stuff with good packets ****************************************
       //Here's a easy way to split the fields into a string array
       fieldarray() = split(mid(packet,1),GB_fieldseparator)
       //Update display
       for i = 1 to GB_fieldcount
           Main.field(i).text = fieldarray(i)
       next i
       //Keep track of good packet count
       good_count=good_count+1 Main.GoodPackets.AppendText " [ "+str(ldata)+" ]"+packet+chr(13) 
       Main.GoodCount.text=str(good_count)
       //Just to demonstrate that while the Arduino is talking to me I can talk to it as well //Toggle status of LED on every good packet
       //Send "H" or "L" back to Ardunio to change staus on PIN 13 LED
       If GB_LED_status=TRUE then
             Main.LED.fillcolor=&cFF0000 //Update display RED
            Main.SerialCom.write ("H")
            GB_LED_status=FALSE
       else
            Main.LED.fillcolor=&c00FF00 //Update display GREEN
            Main.SerialCom.write ("L")
            GB_LED_status=TRUE
       end if
   else
       //This is where you reject packets which either do not begin with the record separator //or are not the expected length.
       //Keep track of sync errors
       sync_error_count=sync_error_count+1 
       Main.BadPackets.AppendText " [ "+str(ldata)+" ]"+packet+chr(13)
       hexstring=EncodeHex(packet,TRUE)
       Main.BadPackets.AppendText hexstring+chr(13)
       Main.SyncErrorCount.text=str(sync_error_count)
   end if
   return ldata
 else
   return 0

end if

End Function

GB_fieldcount As Integer

GB_fieldseparator As string

GB_LED_status As Boolean

GB_recordlength As Integer

GB_recordseparator As string

End Module