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14. Interface and Application Programming

This week’s individual assignment is to write an application that interfaces a user with an input &/or output device that you made.

I used the sound sensor board and t3216 breakout board which I made.

Link to Group assignment

I tried Blynk as written in 1. Switch On and Off from iPhone (Ishimura) section.

Sound sensor & Processing

I ran the program which was used to test my Sound Sensor board uploading to t3216 from Ardunino IDE and showing the result on a browser by Processing.

I followed below steps.

1. Cabling the t3216 and the sensor board

Board 1 2 3
Sound sensor VCC GND OUT
t3216 VCC GND PA7

2. Activate the program in Arduino


// Connect the MEMS AUD output to the t3216 breakout board PA7 pin
int mic = A7; //tentatively change from A7

// Variable to hold analog values from mic
int micOut;

void setup() {


void loop() {
  // read the input on analog pin 0:
  micOut = analogRead(mic);

  // print out the value you read:


3. Install Processing

Download site

4. Run Processing Program

  • Current Port is “/dev/cu.usbserial-D307RGA2”

  • Code

import processing.serial.*;

Serial port;

float x;
float y;

int in_data;

void setup() {
 size(300, 300);
 port = new Serial(this, "/dev/cu.usbserial-D307RGA2", 9600);
 background(0, 0, 0);

void draw() {
 // set drawing area
 fill(255, 10);
 rect(0, 0, width, height);

 // receive data from serial port
 if (port.available() > 0 ) {
   // receipt of serial data
   in_data =;

   // drawing
   x = width  / 2 + random(-3, 3);
   y = height / 2 + random(-3, 3);


   stroke(random(255), random(255), 255);

   ellipse(x, y, in_data, in_data);

## Results

Sound sensor is catching sounds and Processing is drawing in browser.

video link


I had been thought that applications which is working on iPhone and Browser are too difficult for me to handle before this session. This week I had experiences of Processing and Blynk(as Group assignment). They were very handy and so interesting. I’d like to make good use of one of them in my Final Project.

Notes :

  • We cannot open Serial Monitor of Arduino and Processing drawing at the same time.
  • We need start from Arduino, then work on Processing.

Reference site( in Japanese ):


Last update: July 5, 2021