Putting it all together

Code from class, circuit schematics, etc. are at the bottom

Let’s get the chocolate in the peanut butter

• Serial communication – you’ve already done this! Serial monitor in Arduino
  • Give us even more power to compare different things in unique and weird ways
  • sending voltage along the USB cable to represent numbers, letters, and punctuation
    • one number/letter is easy
    • more will require you to make up your own protocol (agreement between systems)
      • Physical system is already determined for us, as is the mechanism for communication.
      • We’re gonna make up our own words and hooks that uniquely identify our information (formatting above all else)
      • baud rate must be in agreement
    • println() on Arduino side – just like the serial monitor. Gonna replace the duck with a processing program
• Processing doesn’t have a native idea of serial (Arduino can only communicate with one other thing, Processing can communicate with many at the same time).
  • Make sure Arduino is sending information
  • Close serial monitor (Ardy can only talk to one at a time)
  • import serial lib
    
    Java

    import processing.serial.*;

    1	import processing.serial.*;

  • make serial object & initialize
    • need to choose the correct port
      
      Java

      println(Serial.list()); // Print out the list and look for port your Microcontroller is on // Finding the Arduino is not easy because they have weird names like "/dev/tty.usbmodem1421" or COM1 String portName = Serial.list()[0]; myPort = new Serial(this, portName, 9600);

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      println(Serial.list());   // Print out the list and look for port your Microcontroller is on   // Finding the Arduino is not easy because they have weird names like "/dev/tty.usbmodem1421" or COM1   String portName = Serial.list()[0];   myPort = new Serial(this, portName, 9600);

  • set up listener/callback/what have you
    
    Java

    myPort.readStringUntil('\n');

    1	myPort.readStringUntil('\n');

    
    This gets paired with a freebie function serialEvent. It waits until a newline character (the ‘\n’) is received.
    
    Arduino

    void serialEvent(Serial _port) { //this is a callback function if (myPort == null) return; //this is a hack to cover a bug where the port does not get set up in time. //this says if the port is not set up yet, bail (for now.) String input = myPort.readStringUntil('\n'); if (input != null) { //if a '\n' character has in fact now arrived input = input.trim(); //Take off the '\n' character size = int(input); //Turn it into number println(xpos); } }

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    void serialEvent(Serial _port) { //this is a callback function   if (myPort == null) return;  //this is a hack to cover a bug where the port does not get set up in time.     //this says if the port is not set up yet, bail (for now.)   String input = myPort.readStringUntil('\n');   if (input != null) {  //if a '\n' character has in fact now arrived     input = input.trim();  //Take off the '\n' character     size = int(input);  //Turn it into number     println(xpos);   } }

    • This converts the text from Arduino into numbers that Processing can use.
• Arduino can send raw bytes (an 8-bit value between 0-255), and that’s great if you’re an engineer. For the rest of us, it’s better to think about text. It’s easier to read & debug, you can send arbitrarily long numbers, and it’s easier to send multiple pieces of data because it allows for non-numeric characters that can act as delimiters.
  • How ASCII works
• ASCII Table is the nerdiest website I know by heart.
• sending multiple bits from Arduino to Processing (CallResponseASCII)
• Sending from Processing to Arduino (Physical Pixel)
  • This is the exception to the rule, it’s easier to send bytes to a micro controller. (physical pixel/dimmer)
  • Picture to Pixel
• Examples from class
  – Space Invaders (Handshake, 2 sensors to Processing)
  – Pixel to RGB LED (multiple bytes to Arduino)
  – Dimmer (one byte to Arduino)
  – Expanding Circle (one sensor to Processing)