All Posts

Assignment 7: Musical Instrument (Maryam & Ian)

Christmas is in the Air

Concept: 

Christmas is growing closer by the day, and where’s the festive mood without some carols? In this project, we are using switches, a piezo buzzer, and a potentiometer that has the five notes needed to play Jingle Bells. Switches 1 through 5 represent nodes C5, D5, E5, F5, and G5 in order. The LED on pin 13 lights up when you switch between nodes. The potentiometer lets you control the tempo. If you are not familiar with the notes, you follow the order below to play the song.

%%%%%%%%%%%

3,3,3

3,3,3

3,5,1,2

3

4,4,4,4,

4,3,3,3,3

3,2,2,3

2,5

%%%%%%%%%%%

The Switches:

In the beginning, we thought about using distance measurement sensors. We would then map different nodes of the song to the numbers we read from the sensor in a way that the tempo would increase and decrease as you get closer or farther from the sensor. But we wanted defined and distinct sounds and a more exact mapping so we decided to go with a digital I/O instead. We were also aiming to use the potentiometer to control volume initially but the buzzer was acting strange with the signal change in the potentiometer. Later we figured it was better and more practical to control the tempo via a potentiometer (the default tempo is 8).

The five nodes in the program C5, D5, E5, F5, and G5 are defined in “pitches.h”. The song sheet is converted to code taken and provided by Project Hub and there is also a tutorial on how to do it yourself by Nathan Seidle on Github.

// %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
void loop() {

  int knob = analogRead(A2);
  Serial.println(knob);

  tempo = map(knob, 0, 1024, 60, 255)/15;

  switchOne = digitalRead(2);
  switchTwo = digitalRead(3);
  switchThree = digitalRead(4);
  switchFour = digitalRead(5);
  switchFive= digitalRead(6);
  
  if (switchOne == HIGH) {
    sing(1);
  } else if (switchTwo == HIGH) {
    sing(2);
  } else if (switchThree == HIGH) {
    sing(3);
  } else if (switchFour == HIGH) {
    sing(4);
  } else if (switchFive == HIGH) {
    sing(5);
  }
}
// %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Full code on p5.js can be found here.

The Potentiometer:

After realizing that using the potentiometer for volume control would be difficult to do with our buzzer, we decided to use it as a means to control the tempo settings (the length of each note) of our instrument. This part of the code is used to achieve this:

void loop() {
//Potentiometer Value is Assigned to knob
  int knob = analogRead(A2);
//Tempo is Remapped and Divided
  tempo = map(knob, 0, 1024, 60, 255)/15;
. . .
//Tempo is Used to Determine Note Duration
  int noteDuration = 1000 / tempo;
  tone(melodyPin, c5, noteDuration);
}

With each loop, the value of the potentiometer is read and updated to the integer knob, which is subsequently remapped and divided; this value is then called to calculate noteDuration, which is used as a parameter that determines the length of the note played though tone(). According to this code, turning the potentiometer clockwise increases the length of a single note, while turning it counterclockwise achieves the opposite. With the potentiometer set up, our project can emit tones of differing pitches and lengths, allowing us to play neat little songs like Jingle Bells!

Demo:

Reflection:

It was an enjoyable and rewarding experience to brainstorm and collaborate on this project as a group! It definitely helped to have each other to consult (and commiserate with) when we were stuck at certain points. If we were to have more time, we would have liked to decorate our instrument with LEDs that correspond to the notes being played; regardless, we’re very proud with what we were able to achieve with this project. With each project, our familiarity with Arduino grows—and in this case, so did our teamwork. Coupled with a nice carol, this project really harnesses the Christmas spirit!

Assignment 7: Ahmed and Abigail’s Music Device

Concept

Honestly, we had some trouble brainstorming for this assignment at first. We weren’t sure what instrument to create or mimic and how. However, after watching a video about the theremin we decided to make an instrument that would react to the distance between our hands and some sensor. We also wanted to recreate the drone of old midi modulating synths.

For that, we needed to use an ultrasonic distance finder and the HC-SR04 sensor in our kit was perfect for that. Also, we wanted to be able to control the itch of the sound being produced so we used a potentiometer for that. We decided to use a speaker available at the IM lab, a switch, and an enclosure to build the whole project.

 

Brainstorming:

While looking for inspiration and knowledge necessary for implementing our idea we came across the following youtube video that outlined how to make a simple ‘instrument’ using an ultrasonic distance sensor:

Musical Instrument Using Arduino + Ultrasonic Distance Sensor

This video allowed us to build a device that could convert distance measurements into different musical notes.

After this, we used some other sources to understand better the use of ultrasonic distance sensors and also how to integrate switches and potentiometers into the circuit:

Arduino Potentiometer – Complete Tutorial

Ultrasonic Sensor HC-SR04 with Arduino Tutorial

Process & Code

For the code, it was a bit difficult to figure out how to use the ultrasonic range finder at first. We had to figure out how to convert time to distance since the sensor needs to listen for a pulse from an object to return and the returning pulse is proportional to the distance of the object from the sensor. Luckily, we found exactly what we were looking for in a tutorial on the internet. However, it was calibrated for a few meters instead of a few inches. We needed something that was more sensitive and produced a different set of frequencies. We decided that we would do that by reducing the maximum distance to a few inches and increasing the sensitivity. We also tweaked the code to put the speaker in a continuous loop instead of just beeps to give us a more synth-esque sound.

The sensor itself was difficult to calibrate but after referring to the aforementioned sources we were able to discover some useful functions like the delayMicroseconds() and microsecondstoInches()

// The ping is triggered by a HIGH pulse of 2 or more microseconds.
// Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
pinMode(3, OUTPUT);// attach pin 3 to Trig
digitalWrite(3, LOW);
delayMicroseconds(2);
digitalWrite(3, HIGH);
delayMicroseconds(5);
digitalWrite(3, LOW);
cm = microsecondsToCentimeters(duration);

For the potentiometer, we added the following code to make it emit certain frequencies of sound depending on the position of the knob:

int potVal= analogRead(potentiometerPin);
int speakerVal = potVal * 5 ;
Serial.println((String)potVal + " -> " + (String) speakerVal);
tone(speakerPin, speakerVal );

Below is our initial setup:

after hooking it up to the speaker this is what it sounded like:

However, we were still missing a key feature of the assignment which was a button to control the sound output. For that, we used the following simple line of code to detect whether the signal output from the switch was HIGH or not:

buttonState = digitalRead(buttonPin);
  if (buttonState == HIGH)

If this statement was held true, it would continue the loop that would initialize the ultrasonic distance sensor and then output a sound signal depending on the position of the hands.

To connect the wires to the button and the ultrasonic distance sensor we had to solder the wires to ensure a strong and secure connection:

The circuit diagram of the final circuit:

Final project:

The look of the final project assembled:

Reflection and Difficulties:

This project was a lot of fun for both of us. We both learned some important information about using distance sensors and the inbuilt functionality of Arduino IDE that helps make a lot of information processing very easy as a programmer. We also had to solder which was a new experience and allowed us to gain important hands-on knowledge in building practical circuits. Some of the difficulties we faced included code optimization and building usable circuits.

We also learned the importance of top-down development in building circuits; we used a multitude of resources and examples and our own creativity to create circuits with a lot of unnecessary parts. After tinkering and experimenting we were able to streamline not only our circuit to be as simple as functionally possible while losing no part of the usability.

With complex circuits, we discovered that cable management was very important and some of our components were regularly shorting. to reduce this effect we used tape and insulators but it was still far from perfect. Additionally, we could have used heat-shrinking insulating wraps to create better insulation.

Also, we had trouble using the buttons available in the kit because they were pushing buttons and not permanent switches. The fix was super easy thankfully and only required replacement parts that we found in the lab.

Assignment 7: Music Machine by Nouf and Vivianna

Our idea for the musical instrument was to use sounds that the servo motor created rather than incorporating the piezo buzzer. So, we decided to try and recreate a gumball machine and the sound it makes when the gumballs fall out of the machine.

The Physical Design Process

We built the structure using a box, water bottle and cardboard. We then prepared the servo motors and prepared a cardboard piece to act as a ball stopper to control the amount of balls that fall through the hole.

We attached the servo motor and started testing out the servo motor with balls made from different materials to see what sound they made. We also decided to create two ramps for the balls to slide on to make more sound. As for the materials, we used pipe-cleaners, paper, and marbles. We found that the marbles made the best sound and rolled nicely down the ramp. The paper balls made a decent sound, whereas the pipe-cleaners were almost silent when they fell.

Different materials used for the ball

Here is the final version of the physical components:

And here is the schematic of our circuit:

Some things that didn’t work out as expected…

Our initial plan was to have the balls fall down one by one, but that didn’t work as expected. The balls either fell together when the ball stopper opened, or they would get stuck even when the stopper opened. When they do fall down, most of the time they wouldn’t roll down the ramps as intended. Usually, the balls would fall to the side, fall straight down, or when it does fall on the slide it wouldn’t roll all the way down and it would get stuck on the ramp. In this case, the marbles worked best since they were smooth spheres, but the marbles also had the problem with falling to the side. Additionally, at first we wanted the stopper to open and close continuously after one button press, but currently it just does the cycle once and you have to keep pressing the button for the continuous opening and closing.

The Coding Process

For implementing the sensors, we decided to use a push button and potentiometer. We used the button to control the servo motor, which either blocks or unblocks the hole where the balls fall out of. When it is open the balls fall out, and when it is closed the balls are stopped. To do this we used 2 if statements that checked if the button is clicked once, in which case the lever is opened, and if the button is clicked again then the lever is closed again.

 if(clicks%2 == 0)
 {
   pos = 0;
 }
 else{   
   if (pos <= 70)
   {
     pos += servoSpeed;
   }
}
 
myServo.write(pos);
delay(100);  

Another variation of code was to have one press do both the opening and closing of the ball stopper. This was the code we used:

if (buttonState == 1){
   for (pos = 0; pos <= 160; pos += servoSpeed) {
      myServo.write(pos);             
      delay(15);                       
   }
   for (pos = 70; pos >= 0; pos -= servoSpeed) {
      myServo.write(pos);              
      delay(100);               
   }
  } else if (buttonState == 0) {
    myServo.write(70);
    delay(15);
  }

This is the link to the full code

We experimented with the delay, and the number for the position of the servo motor. If we made the delay longer, the servo motor would take longer to reach the position. Moreover, since the potentiometer controls the speed of the servo motor, when the potentiometer is at the maximum number, the servo motor moves faster, but since the delay is longer it doesn’t seem as fast. When the delays were all set to 15 and the potentiometer was at the maximum, the servo motor didn’t sweep the full amount (i.e. it didn’t complete the number of degrees in the for loop). While this was experimental, we ended up liking the sound it created and the movements of it.

Finally, here are a few different videos of our music machine!

This one is the first code, where one press opens and the other press closes it:

 

This one all the delay amounts are the same. We didn’t experiment with the potentiometer for this version, but the sound was nice:

 

This one has one long delay:

 

And this final one we tested with just marbles and shortened the long delay, which was in the previous video:

IM Assignment Week 10 – Maryam and Ian

Christmas is in the Air

Concept: 

Christmas is growing closer by the day, and where’s the festive mood without some carols? In this project, we are using switches, a piezo buzzer, and a potentiometer that has the five notes needed to play Jingle Bells. Switches 1 through 5 represent nodes C5, D5, E5, F5, and G5 in order. The LED on pin 13 lights up when you switch between nodes. The potentiometer lets you control the tempo. If you are not familiar with the notes, you follow the order below to play the song.

%%%%%%%%%%%

3,3,3

3,3,3

3,5,1,2

3

4,4,4,4,

4,3,3,3,3

3,2,2,3

2,5

%%%%%%%%%%%

The Switches:

In the beginning, we thought about using distance measurement sensors. We would then map different nodes of the song to the numbers we read from the sensor in a way that the tempo would increase and decrease as you get closer or farther from the sensor. But we wanted defined and distinct sounds and a more exact mapping so we decided to go with a digital I/O instead. We were also aiming to use the potentiometer to control volume initially but the buzzer was acting strange with the signal change in the potentiometer. Later we figured it was better and more practical to control the tempo via a potentiometer (the default tempo is 8).

The five nodes in the program C5, D5, E5, F5, and G5 are defined in “pitches.h”. The song sheet is converted to code tokens and provided by Project Hub and there is also a tutorial on how to do it yourself by Nathan Seidle on Github.

// %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
void loop() {

  int knob = analogRead(A2);
  Serial.println(knob);

  tempo = map(knob, 0, 1024, 60, 255)/15;

  switchOne = digitalRead(2);
  switchTwo = digitalRead(3);
  switchThree = digitalRead(4);
  switchFour = digitalRead(5);
  switchFive= digitalRead(6);
  
  if (switchOne == HIGH) {
    sing(1);
  } else if (switchTwo == HIGH) {
    sing(2);
  } else if (switchThree == HIGH) {
    sing(3);
  } else if (switchFour == HIGH) {
    sing(4);
  } else if (switchFive == HIGH) {
    sing(5);
  }
}
// %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

Full code on p5.js can be found here.

The Potentiometer:

After realizing that using the potentiometer for volume control would be difficult to do with our buzzer, we decided to use it as a means to control the tempo settings (the length of each note) of our instrument. This part of the code is used to achieve this:

void loop() {
//Potentiometer Value is Assigned to knob
  int knob = analogRead(A2);
//Tempo is Remapped and Divided
  tempo = map(knob, 0, 1024, 60, 255)/15;
. . .
//Tempo is Used to Determine Note Duration
  int noteDuration = 1000 / tempo;
  tone(melodyPin, c5, noteDuration);
}

With each loop, the value of the potentiometer is read and updated to the integer knob, which is subsequently remapped and divided; this value is then called to calculate noteDuration, which is used as a parameter that determines the length of the note played though tone(). According to this code, turning the potentiometer clockwise increases the length of a single note, while turning it counterclockwise achieves the opposite. With the potentiometer set up, our project can emit tones of differing pitches and lengths, allowing us to play neat little songs like Jingle Bells!

Demo:

Reflection:

It was an enjoyable and rewarding experience to brainstorm and collaborate on this project as a group! It definitely helped to have each other to consult (and commiserate with) when we were stuck at certain points. If we were to have more time, we would have liked to decorate our instrument with LEDs that correspond to the notes being played; regardless, we’re very proud with what we were able to achieve with this project. With each project, our familiarity with Arduino grows—and in this case, so did our teamwork. Coupled with a nice carol, this project really harnesses the Christmas spirit!

Distance musical instrument, Tarek Nabeh & Aadil Zakarya

Concept:

We wanted to create a musical instrument that works without touching anything (of course but the switch button). So we used the ultrasonic sensor to control the frequency of the sound outputted by the buzzer. While coding we found it very annoying for the buzzer to run all of the time, without any option to stop it. Hence, we found it critical to add a button that controls whether the ultrasonic sensor and the buzzer are running. We also wanted to make it fancy in a way that you don’t hold the button for it to work but just press on it to start and press again to stop it, and that’s what we did. The ultrasonic measures the distance by the duration of time of the ultrasonic wave takes to come back, and by that controls the frequency of the buzzer. We also created a feedback loop from the serial by which we can know the distance and the frequency outputted.

Code:

The pins were declared:

int buttonPin = 2;
int echo = 6;
int trig = 5;
int speaker = 9;
long duration;
long distance;
bool isPressed = false;

then the ultrasonic trig and echo were settled up to the pins and the serial was set up as well:

void setup() {
  // setup pin modes
  Serial.begin(9600);
  pinMode(speaker, OUTPUT);
  pinMode(trig, OUTPUT); 
  pinMode(echo, INPUT);
  // pinMode(buttonPin, INPUT);
  // pinMode(buttonPin, INPUT_PULLUP);
}

the void loop basically has everything to do with the switch. a global variable was declared so that we save the last state of the ultrasonic and the buzzer, and when the button is pressed it switches the state. so when if the sensor is not running it makes it start running and vice versa. Moreover, I noticed that a delay had to be added because the void loop runs numerous times while the button is being pressed so it basically turns the sensor on and off numerous times giving us a 50% possibility of tuning the sensors on when the button is released. Hence, the delay is crucial for the project to work.

void loop() {
  digitalWrite(trig, LOW);
  delayMicroseconds(2);
  int buttonState = digitalRead(buttonPin);
  if(buttonState == HIGH){
    Serial.println("button pressed");
    // delay(5000);
    if(isPressed == false){
      isPressed = true;
      delay(1000);
      
    }else if(isPressed == true){
      Serial.print("came pressed ");
      noTone(speaker);
      isPressed = false;
      Serial.println(isPressed);
      delay(1000);
    }    
    // blink(2);
  }
  // Serial.println(isPressed);
  if(isPressed == true){
    updateSensor();
  }
}

Finally, the function that makes the sensor work, as in Tarek’s previous project the sensor calculates the distance by measuring the time it takes for the waves to go out and come back to the sensor again. based on that it scales the distance from 0 to 100 cm to the frequencies from 0 to 455. then it makes the buzzer start the sound in that specific frequency.

void updateSensor(){
  digitalWrite(trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(trig, LOW);
  duration = pulseIn(echo, HIGH);
  distance = duration * 0.034 / 2; 
  int frequency = ((int)(distance * 4.55) );
  frequency = (frequency > 455)? 455 : frequency;
  Serial.print("Distance: ");
  Serial.print(distance);
  Serial.print(" cm, ");
  Serial.print("frequency: ");
  Serial.println(frequency);
  tone(speaker,frequency);
  delay(200);
}

Reflections:

While working on the project we noticed the potential that we have with just this Arduino and minor sensors like the ultrasonic and small gadgets like the buzzer. It also spiked our curiosity to find out what else can be done with such gadgets.

 

rawr

 

concept:

This week required us to utilize the tools offered in the Arduino kit to construct a build that would serve as an instrument! This was extremely fun to work with, especially given the musical background I used to be fond of years ago. The idea revolved around building a piano instrument that would appeal to all different age groups! Going back to this felt nostalgic.

 

process:

The initial plan was to construct a keyboard that would serve as a piano for the user while trying my best to stay away from a cliche approach. As a result, I shifted my focus to an analog perspective and discovered the ultrasonic shock sensor. This was convenient for the approach I was going through as it utilized music and human interaction simultaneously. After researching and finalizing the code, adding an artistic element was essential not only to make it appealing to adults but also children. I sketched, colored, and cut a layout that beautifully complements the program.

 

sketch:

 

future improvements:

Adding LEDs would be beneficial to the young target audience in mind as it would serve as an indicator for them, thus making the functionality easier.

Assignment 7: Musical Instrument

This post is a mirror to the following post: Link

Concept: 

To be frank, we both didn’t really have a mind-blowing, creative inspiration when we got started on this project, which is why we decided to create something that’s simple but also making sure that it will leave enough room for user to be creative with it on our behalf. The idea that we had was to create an instrument that is able to be controlled by the user, such as its beats, pitch, etc., and it consisted of one digital sensor (switch), one analog sensor (potentiometer), and a Piezo speaker, along with the according wires that were needed. Here’s the picture of our initial state that we began with, along with the schematic:

Process/Coding:

While building the circuit itself was fairly easy and efficient since it was just a matter of connecting the wires into the respective places, the coding process was a little bit more complicated as we ran into a few obstacles:

  • Initially, the turn-off function of the switch wasn’t working — this was because of the delay time, so we realized that we had to press on the switch for a while instead of just pressing lightly.
  • We also had to adjust the tone range of our “instrument” — initially it was around 5000, but we later made it to 2000 so that it doesn’t hurt our ears as much even when we turn it up to the maximum tone.
  • Sometimes, the instrument won’t turn off at all even when we pressed down on the switch with enough strength and time; this was due to a small error in the code.

But after a few trials and errors, we were able to fulfill our initial vision for our instrument by controlling both the beat and the pitch either simultaneously or separately.

There was one aspect of the code that was still slightly flawed when we went back to review it, but the final product seemed to work fine despite it so we kept it, which is shown here:

// the loop routine runs over and over again forever:
void loop() {
// read values from potentiometer
int sensorValue = analogRead(potentiometer)/5*5; // <- to mitigate unintended frequency change caused by the sensor
delay(1); // delay in between reads for stability
frequency = map(sensorValue,0,1024,0,2000); // limit frequency range to avoid unpleasant sound
manageOutputPattern(); // determines which sound mode will be played
if (!!outputPattern) { // if outputPattern is 0, idle(). Else make sound.
makeSound();
} else {
idle();
}
// was supposed to do something similar to x 1.3 delay in “ToneMelody” example
// But this is flawed as noteDuration is less than (1300-1000) when BPS is >2.
// However, the product seems to work fine so will not correct this issue.
counter = (counter + 1) % 1300;

To see the entire code, click here.

Final Product: 

Here’s what the final product looked like:

Here’s a brief instruction on how to use the instrument:

  1. When you press on the switch button, the Piezo buzzer will start making sounds.
  2. You can use the potentiometer to control the pitch/tone of the sound and you can use the switch button to control the beat length of each sound. Mind the fact that each time you press on the switch button, the beats will get faster and faster. There will be 5 different beat speed offered.
  3. By pressing the switch button for the 6th time, you will be able to turn off the instrument completely.

…and here’s the video of it running:

Reflection:

Despite some minor hiccups that we’ve faced during the making process, this project was actually pretty manageable and simpler than we thought it’d be! It was exciting to hear how the sound changed as we adjusted the potentiometer/pressed the switch button to create a melody. Potentially creating a song or playing an already existing one by using this instrument that we made will be really fun, and we’re proud of the final product that we ended up with!

Assignment #7: Create Your Own Instrument!

 

Concept: 

To be frank, we both didn’t really have a mind-blowing, creative inspiration when we got started on this project, which is why we decided to create something that’s simple but also making sure that it will leave enough room for user to be creative with it on our behalf. The idea that we had was to create an instrument that is able to be controlled by the user, such as its beats, pitch, etc., and it consisted of one digital sensor (switch), one analog sensor (potentiometer), and a Piezo speaker, along with the according wires that were needed. Here’s the picture of our initial state that we began with, along with the schematic:

Process/Coding:

While building the circuit itself was fairly easy and efficient since it was just a matter of connecting the wires into the respective places, the coding process was a little bit more complicated as we ran into a few obstacles:

  • Initially, the turn-off function of the switch wasn’t working — this was because of the delay time, so we realized that we had to press on the switch for a while instead of just pressing lightly.
  • We also had to adjust the tone range of our “instrument” — initially it was around 5000, but we later made it to 2000 so that it doesn’t hurt our ears as much even when we turn it up to the maximum tone.
  • Sometimes, the instrument won’t turn off at all even when we pressed down on the switch with enough strength and time; this was due to a small error in the code.

But after a few trials and errors, we were able to fulfill our initial vision for our instrument by controlling both the beat and the pitch either simultaneously or separately.

There was one aspect of the code that was still slightly flawed when we went back to review it, but the final product seemed to work fine despite it so we kept it, which is shown here:

// the loop routine runs over and over again forever:
void loop() {
  // read values from potentiometer
  int sensorValue = analogRead(potentiometer)/5*5;  // <- to mitigate unintended frequency change caused by the sensor 
  delay(1);  // delay in between reads for stability
  frequency = map(sensorValue,0,1024,0,2000); // limit frequency range to avoid unpleasant sound

  manageOutputPattern(); // determines which sound mode will be played

  if (!!outputPattern) { // if outputPattern is 0, idle(). Else make sound.
    makeSound();
  } else {
    idle();
  }

  // was supposed to do something similar to x 1.3 delay in "ToneMelody" example
  // But this is flawed as noteDuration is less than (1300-1000) when BPS is >2. 
  // However, the product seems to work fine so will not correct this issue.
  counter = (counter + 1) % 1300;

To see the entire code, click here.
Final Product: 

Here’s what the final product looked like:

Here’s a brief instruction on how to use the instrument:

  1. When you press on the switch button, the Piezo buzzer will start making sounds.
  2. You can use the potentiometer to control the pitch/tone of the sound and you can use the switch button to control the beat length of each sound. Mind the fact that each time you press on the switch button, the beats will get faster and faster. There will be 5 different beat speed offered.
  3. By pressing the switch button for the 6th time, you will be able to turn off the instrument completely.

…and here’s the video of it running:

Reflection:

Despite some minor hiccups that we’ve faced during the making process, this project was actually pretty manageable and simpler than we thought it’d be! It was exciting to hear how the sound changed as we adjusted the potentiometer/pressed the switch button to create a melody. Potentially creating a song or playing an already existing one by using this instrument that we made will be really fun, and we’re proud of the final product that we ended up with!

Week 10: Air Piano

This is a fun instrument that lets you play simple tunes by waving your hands in the air!!

The basic idea is to be able to generate different frequencies of sound based on the position of your hand, which is sensed using an ultra-sonic sensor.

For this to work, the sensor has to be an open space such that there are no obstacles in front of it for at least a meter. Place your palm or any other obstacle in front of the sensor to obtain varying frequencies.

Schematics using Fritzing:

Here’s the code that makes it all work:

#define echoPin 6 
#define trigPin 5 
long duration; // variable for the duration of sound wave travel
int distance; // variable for the distance measurement
int tones;  
int tim=200;// duration for which one sound pulse will last
int buzzerPin = 8;
int space =500;

void setup() {
  pinMode(trigPin, OUTPUT); // Sets the trigPin as an OUTPUT
  pinMode(echoPin, INPUT); // Sets the echoPin as an INPUT
  pinMode(buzzerPin, OUTPUT);
  }
  
void loop() {
  
  //Finding distance of obstacle using ultrasonic sensor
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  
  duration = pulseIn(echoPin, HIGH); // Reads the echoPin, returns the sound wave travel time in microseconds
  distance = duration * 0.034 / 2; // Distance = time*speed/2
  
  //Emitting sound as per the distance
  
  tones =20+distance*5; //calculating the frequency that has to be emitted

   tone(buzzerPin, tones, tim); //emits sound at the specified frequency and for the specified duration
    
   delay (space); //delay between each beat
  
}

Improvements:

In the given code the sounds are emitted at a fixed time interval for a fixed duration. We can play around with this by changing the value of the variables ‘tim’ and ‘space’. Also, we can play around with the way the frequency is calculated from the distance.

Week 9: Digital Input-Output

Ramp Lights!

This week we learned how to control and manipulate digital and analog input/outputs on Arduino IDE. It was interesting how a few lines of code with basic instructions could control a physical output like an LED. For the assignment, I created a ramp light sequence (imagine lights turning on one by one on a ramp, tried to recreate that). The lights turn on sequentially with the rotation of a potentiometer. Here’s a video of how that turned out:

How it works:

The working of this is very simple: the potentiometer has values calibrated with its rotation, so I took those values as input and using if and else if conditions, I changed the state of the LEDs to HIGH or LOW.

The Schematics:

Here’s a diagram of the schematics made using Fritzing:

Arduino IDE code:

int potPin = A5;
int ledPin1 = 2;
int ledPin2 = 3;
int ledPin3 = 4;
int ledPin4 = 5;

void setup() {

  pinMode(potPin, INPUT);
  pinMode(ledPin1, OUTPUT);
  pinMode(ledPin2, OUTPUT);
  pinMode(ledPin3, OUTPUT);
  pinMode(ledPin4, OUTPUT);
  Serial.begin(9600);

}

void loop() {
  int potValue = analogRead(A5);
  Serial.println(potValue);

  if (potValue < 100) {
    digitalWrite(ledPin1, LOW);
    digitalWrite(ledPin2, LOW);
    digitalWrite(ledPin3, LOW);
    digitalWrite(ledPin4, LOW);
  }
  
  else if (potValue < 256) {
    digitalWrite(ledPin1, HIGH);
    digitalWrite(ledPin2, LOW);
    digitalWrite(ledPin3, LOW);
    digitalWrite(ledPin4, LOW);

  }

  

  else if (potValue < 512) {
    digitalWrite(ledPin1, HIGH);
    digitalWrite(ledPin2, HIGH);
    digitalWrite(ledPin3, LOW);
    digitalWrite(ledPin4, LOW);
  }

  else if (potValue < 768) {
    digitalWrite(ledPin1, HIGH);
    digitalWrite(ledPin2, HIGH);
    digitalWrite(ledPin3, HIGH);
    digitalWrite(ledPin4, LOW);
  }

  else if (potValue < 1024) {
    digitalWrite(ledPin1, HIGH);
    digitalWrite(ledPin2, HIGH);
    digitalWrite(ledPin3, HIGH);
    digitalWrite(ledPin4, HIGH);
  }


}

It was fun creating the ramp lights and seeing the lights turn on/off with the turn of my potentiometer!