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      Week 12: Interface and Application Programming    
    • Learning Objectives (Week 12):
    • 12.0. Notes during the class and workshops:
    • 12.1. This week, I've been up to:
    • 12.2. Process of writing an application that interfaces a user with an output device that I made
    • 12.3. Explanation of how the UI that I made works, and how I did it
    • 12.4. Creating and breaking problems ~~ and how I fixed them
    • 12.5. Source code && Hero shot/video
    • 12.6. Week 12 Files
    • 12.7. The Fun Discoveries of The Week, && the Questions of the Week 9
    • 12.8. Hi Neil -- I watched Neil's talks and interviews

      • L.O. (Learning Objectives) Week 12:¶

      ¶

          
      •	Document while learning from writing an application that interfaces a user with an output device that I made
      •	Explain the UI that I made and how I did it
      •	Create and break problems ~~ and how I fixed them
      •	Journal the Fun Discoveries of The Week, && the Questions of the Week 12
      •	Be myself.

      12.0. Notes during the class and workshops:FABLAB¶

       
        •	IoT-related device interfaces:
            o	MQTT, XMPP, IFTTT, UPnP, Wemo
        •	Relationship between IoT and UI(User Interface)
            o	IoT: distributed sensors
            o	UI: for display
        •	Data visualization vs. UI
            o	Data visualization: one-way communication
            o	UI: mutual, both way communication
                  	There should be 
        •	WebGL vs. Three.js ?
        •	The difference is “optimization”
        •	Options for the week:
            o	App inventor
                  	E.g. heart rate 
            o	Node-RED
                  	E.g. 
            o	Python
                  	TKinter library
            o	Processing
        
        •	Bantam-related tips
            o	Clearance 0.42 – 1.2
            o	Trace width 0.4 – 1.2
                  	Fatter traces are useful when you need more power(P)
        •	E.g. for LED, Motor, Heaters
        •	Pinouts
            o	Search word: “Minimal circuit”
            o	ISP
                  	Is used for 44, 45, 85, 128, 328, 2506, mega
            o	Jtag
                  	SAMD
            o	UPDI
                  	412, 1614, 3216
            o	FTDI
                  	TX, RX communication (USB -> Serial)
        •	Capacitor(s) is always for one particular component(chip)
             o	Therefore, it is important/better to put a capacitor right next to the particular component that the capacitor supports/is for.

      12.1. This week, I've been up to:¶

      There are three things that I have been working on:
      (In chronological order)
      1. getting help for soldering my speaker board (My skin shows alergetic reation when/after soldering)


      2. getting ready with an oven to use "Reflow Method" for soldering



      3. setting up an serial communication in my interface (Python used)




      Group Work:
      wk12_group_work_webpage

      12.2. Process of writing an application that interfaces a user with an output device that I made:¶

      At first, I tried NODE-RED with a LED-and-Switch board that I made:

      (This photo arduino reference related to serial communication.)
      After using NODE-RED during the workshop, I thought it would work okay with my output device board (speaker board) and my final project.
      So I took a few steps to understand how node-red works (a.k.a. "Stack Development"). And this is the result (mix of my handwriting and Craig's):

      (Useful tutorial for getting started with NODE-RED)
      (How to run NODE-RED locally)
      Then I realized I should use NODE-RED after setting up a workflow for "Reflow Method" to re-solder my heartbeat sensor board (input device board).
      To me, NODE-RED seemed to be more interesting with input devices.
      I also thought of using Processing, but I have already used Processing for UI-related stuff before.
      (Processing Reference Page)

      Therefore, I switched to Python.
      I found this tutorial helpful to get started with GUI in Python.
      After installing pip3 and pyserial libraries, a practice code that I wrote worked.

      Then I wrote this code, shown below, to make "Play" and "Stop" buttons in my interface for the speaker board.

      **Trouble-shooting here -- which i will talk through in 12.4 part of this webpage.



      12.3. Explanation of how the UI that I made works, and how I did it:¶

      12.4. Creating and breaking problems ~~ and how I fixed them:¶

      Problem 1 (Serial communication across Python, Arduino, and the boards)
      The buttons worked:


      However, their output did not connect with the board well.
      It seemed to send something as there's a blink on the UNO board.

      Then I tested on a new, plain? UNO board with nothing attached to it.

      I modified the example code found in the Arduino platform. ("communication >> Serial Event")
      This example code worked, and I used this understanding to add this part:

      to the Speaker_Code.
      It seemed to send something as the speaker makes a noise right after I upload the code, but it didn't seem to connect with the python interface.

      Later, I discovered that I should not use "Digital Write" because I'm doing serial communication using python for which it is better to use hardware pins, not software pins. (I forgot the detailed reason.)

      Problem 1 -- Solution:

      I decided to call a function rather than using digital-write.


      Problem 2:
      There were no errors in the Arduino code, but the speaker kept making a weird noise that may be caused by loose wires.



      Problem 2 -- Solution:
      And in the process, I asked a few questions and learned these things:


      Then I realized I forgot to plug in TX and RX of my Speaker_Board to the arduino UNO that I used.
      So I correctly pluged them in to the right pin numbers.


      Problem 3:
      The speaker kept making the same noise. (The Speaker_Board works when I upload the version of the code that does not communicates with the interface python code.)


      Problem 3 -- Solution:
      I changed a separte function in Arduino and made the loop section empty.
      It made the overall arduino code more organized and easier to understand.
      And I hoped it would solve the half-unknown-half-known issue that I have been facing.



      Problem 4:
      I had to check in detail whether or not all the data types used both in python and arduino are the same (e.g. byte, string, or character).


      Problem 4 -- Solution:
      Therefore I looked into the main parts that I had to check more carefully.
      And I re-read the datatype parts in the arduino reference page.




      And now I am currently working on "TYPE CASTING".
      I'm currently trying character, but might change to integer later depending on the results of experiments.

      12.5. Source code && Hero shot/video:¶

      Python working -- Video:


      Python Code: 

       
      
      
      from tkinter import *
      import serial

      WINDOW = 800 # window size
      eps = 0.5 # filter time constant
      port = '/dev/cu.usbmodem141201'
      baud = 9600

      #  check command line arguments
      #if (len(sys.argv) != 2):
      #   print("command line: hello.load.45.py serial_port")
      #   sys.exit()
      #port = sys.argv[1]

      # open serial port
      ser = serial.Serial(port, baud)
      ser.setDTR()

      # define functions
      def myPlay():
          ser.write(b'1')
          myLabel = Label(root, text="Music is playing...")
          myLabel.pack()
      def myStop():
          ser.write(b'0')
          myLabel = Label(root, text="No more music; silence!")
          myLabel.pack()

      root = Tk()
      #Button = tkinter.Button
      #text = tkinter.Text
      Play = Button(root, text="PLAY", command=myPlay, height=7, width=11)
      Play.pack(side=LEFT)
      Stop = Button(root, text="STOP", command=myStop, height=7, width=11)
      Stop.pack(side=RIGHT)

      # set up GUI
      #root = Tk()
      #root.title('listen.to.my.heartbeat.py (q to exit)')
      #root.bind ('q', 'exit')
      #canvas = Canvas(root, width=WINDOW, heigh=.75*WINDOW, background='magenta')

      # start idle loop
      #root.after(100, idle, root, canvas)
      #Play.pack(side=tkinter.LEFT)
      #Stop.pack(side=tkinter.RIGHT)
      root.mainloop()
      Arduino code - for the python interface code: 
       
      
      
      int speakerPin = 0;

      int sLength = 15; // the number of notes
      char notes[] = "eeeeeeegcde fffffeeeeddedg eeeeeeegcde fffffeeeggfdc "; // a space represents a rest
      int beats[] = { 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4 };
      int tempo = 300;
      
      void setup() {
        // initialize serial:
        Serial.begin(9600);
        // reserve 200 bytes for the input String:
        //inputString.reserve(200);
        pinMode(speakerPin, OUTPUT);
      }
      
      void playSong(/*int note, int tone, int duration*/) {
        for (int i = 0; i < sLength; i++) {
          if (notes[i] == ' ') {
            delay(beats[i] * tempo); // rest
          } else {
            playNote(notes[i], beats[i] * tempo);
          }
      
          // pause between notes
          delay(tempo / 2); 
          }
      }
      
      void playTone(int pTone, int duration) {
        for (long i = 0; i < duration * 1000L; i += pTone * 2) {
          digitalWrite(speakerPin, HIGH);
          delayMicroseconds(pTone);
          digitalWrite(speakerPin, LOW);
          delayMicroseconds(pTone);
        }
      }
      
      void serialEvent() {
        while (Serial.available()) {
          byte inByte = (byte)Serial.read();
          if (inByte == 1) {
            //Serial.print("1");
            //digitalWrite(speakerPin, HIGH);
            Serial.println("PlayingSong");
            playSong();
          }
          else if (inByte == '0') {
            //Serial.print("0");
            //digitalWrite(speakerPin, LOW);
          }
        }
      }
      
      void playNote(char note, int duration) {
        char names[] = { 'c', 'd', 'e', 'f', 'g', 'a', 'b', 'C' };
        int tones[] = { 1915, 1700, 1519, 1432, 1275, 1136, 1014, 956 };
      
        // play the tone corresponding to the note name
        for (int i = 0; i < 8; i++) {
          if (names[i] == note) {
            playTone(tones[i], duration);
          }
        }
      }
      
      void loop() {
        playSong();
      }
      Twinkle Little Star (not for interface-related usage): 
       
      
      
        char notes[] = "ccggaagffeeddc "; // a space represents a rest
        int beats[] = { 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 4 };



      Jingle Bell (not for interface-related usage): 
       
      
      
      int speakerPin = 0;

      int length = 15; // the number of notes
      char notes[] = "eeeeeeegcdefffffeeeeddedgeeeeeeegcdefffffeeeggfdc "; // a space represents a rest
      int beats[] = { 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 1, 1, 2, 1, 1, 2, 1, 1, 1, 1, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4 };
      int tempo = 300;
      
      void playTone(int tone, int duration) {
        for (long i = 0; i < duration * 1000L; i += tone * 2) {
          digitalWrite(speakerPin, HIGH);
          delayMicroseconds(tone);
          digitalWrite(speakerPin, LOW);
          delayMicroseconds(tone);
        }
      }
      
      void playNote(char note, int duration) {
        char names[] = { 'c', 'd', 'e', 'f', 'g', 'a', 'b', 'C' };
        int tones[] = { 1915, 1700, 1519, 1432, 1275, 1136, 1014, 956 };
      
        // play the tone corresponding to the note name
        for (int i = 0; i < 8; i++) {
          if (names[i] == note) {
            playTone(tones[i], duration);
          }
        }
      }
      
      void setup() {
        pinMode(speakerPin, OUTPUT);
      }
      
      void loop() {
        for (int i = 0; i < length; i++) {
          if (notes[i] == ' ') {
            delay(beats[i] * tempo); // rest
          } else {
            playNote(notes[i], beats[i] * tempo);
          }
      
          // pause between notes
          delay(tempo / 2); 
        }
      }

      Node-RED Screenshot:


      Node-RED Working -- Video:

      12.6. Week 12 Files:¶



      12.7. The Fun Discoveries of The Week, && the Questions of the Week 11:¶

       
      
      
      1.

      12.8. Hi Neil -- I watched Neil's talks and interviews:¶

      Video 1:


      Video 2:

      Video 3:


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