Design point of view
I initially got my idea for my final project when i saw Benjamin Williams working on his spy gear. Whenever he pressed the self destruct button LEDs would light up and a sound would play. It was in that moment that I thought of making an 8 bit piano. I realized that this would be a great project for DJ's to experiment with possible electronic sounds. especially because if you press more than one button at a time the Arduino micro interprets it in a way that makes the sound seem distorted (something modern DJs particularly like).
People always talk about why encapsulation is so good, however, one of the reasons that encapsulation is bad is that the user has no idea what is going on inside their devises. I decided to leave the top of my device open so that the user could fully appreciate what they were using and easily make any modifications.
Verplank diagram
Paper prototype
Just a box with 8 keys. I was really shooting for simplicity.
Actual prototype
State diagram
Project code
/*
8 - bit Piano
Plays a different note for each pressed button and plays a distorted sound
i two or more buttons are pressed at the same time.
circuit:
* 8-ohm speaker on digital pin 8
Parts of this example code is in the public domain.
http://arduino.cc/en/Tutorial/Tone
*/
#include "pitches.h"
int melody[] = {
NOTE_D3,NOTE_D3,NOTE_D3,NOTE_G3,NOTE_D4,NOTE_C4,NOTE_B3,NOTE_A3,NOTE_G4,NOTE_D4, \
NOTE_C4,NOTE_B3,NOTE_A3,NOTE_G4,NOTE_D4,NOTE_C4,NOTE_B3,NOTE_C4,NOTE_A3,0};
int noteDurations[] = {
10,10,10,2,2,10,10,10,2,4, \
10,10,10,2,4,10,10,10,2,4};
// constants won't change. They're used here to
// set pin numbers:
const int buttonPin1 = 9;
const int buttonPin2 = 7;
const int buttonPin3 = 6;
const int buttonPin4 = 5;
const int buttonPin5= 4;
const int buttonPin6 = 3;
const int buttonPin7 = 2;
const int buttonPin8 = 10;
// variables will change:
int buttonState1 = 0;
int buttonState2 = 0;
int buttonState3 = 0;
int buttonState4 = 0;
int buttonState5 = 0;
int buttonState6 = 0;
int buttonState7 = 0;
int buttonState8 = 0;
void setup() {
// iterate over the notes of the melody:
for (int thisNote = 0; thisNote < 20; thisNote++) {
// to calculate the note duration, take one second
// divided by the note type.
//e.g. quarter note = 1000 / 4, eighth note = 1000/8, etc.
int noteDuration = 1000/noteDurations[thisNote];
tone(8, melody[thisNote],noteDuration);
// to distinguish the notes, set a minimum time between them.
// the note's duration + 30% seems to work well:
int pauseBetweenNotes = noteDuration * 1.30;
delay(pauseBetweenNotes);
// stop the tone playing:
noTone(8);
}
// initialize the LED pin as an output:
// initialize the pushbutton pin as an input:
pinMode(buttonPin1, INPUT);
pinMode(buttonPin2, INPUT);
pinMode(buttonPin3, INPUT);
pinMode(buttonPin4, INPUT);
pinMode(buttonPin5, INPUT);
pinMode(buttonPin6, INPUT);
pinMode(buttonPin7, INPUT);
pinMode(buttonPin8, INPUT);
}
void loop() {
// read the state of the pushbutton value:
buttonState1 = digitalRead(buttonPin1);
buttonState2 = digitalRead(buttonPin2);
buttonState3 = digitalRead(buttonPin3);
buttonState4 = digitalRead(buttonPin4);
buttonState5 = digitalRead(buttonPin5);
buttonState6 = digitalRead(buttonPin6);
buttonState7 = digitalRead(buttonPin7);
buttonState8 = digitalRead(buttonPin8);
// check if the pushbutton is pressed.
// if it is, the buttonState is HIGH:
if (buttonState1 == HIGH) {
// turn LED on:
tone(8, NOTE_D4);
}
else {
// turn LED off:
noTone (8);
}
if (buttonState2 == HIGH) {
// turn LED on:
tone(8, NOTE_D3);
}
else {
// turn LED off:
noTone (8);
}
if (buttonState3 == HIGH){
tone (8, NOTE_F3);
}
else {
noTone (8);
}
if (buttonState4 == HIGH) {
// turn LED on:
tone(8, NOTE_G3);
}
else {
noTone (8);
}
if (buttonState5 == HIGH) {
// turn LED on:
tone(8, NOTE_GS3);
}
else {
noTone (8);
}
if (buttonState6 == HIGH) {
tone(8, NOTE_B3);
}
else {
noTone (8);
}
if (buttonState7 == HIGH) {
// turn LED on:
tone(8, NOTE_C4);
}
else {
noTone (8);
}
if (buttonState8 == HIGH) {
// turn LED on:
tone(8, NOTE_C3);
}
else {
noTone (8);
}
}
//pitches.h class (taken from lab)
/*************************************************
* Public Constants
*************************************************/
#define NOTE_B0 31
#define NOTE_C1 33
#define NOTE_CS1 35
#define NOTE_D1 37
#define NOTE_DS1 39
#define NOTE_E1 41
#define NOTE_F1 44
#define NOTE_FS1 46
#define NOTE_G1 49
#define NOTE_GS1 52
#define NOTE_A1 55
#define NOTE_AS1 58
#define NOTE_B1 62
#define NOTE_C2 65
#define NOTE_CS2 69
#define NOTE_D2 73
#define NOTE_DS2 78
#define NOTE_E2 82
#define NOTE_F2 87
#define NOTE_FS2 93
#define NOTE_G2 98
#define NOTE_GS2 104
#define NOTE_A2 110
#define NOTE_AS2 117
#define NOTE_B2 123
#define NOTE_C3 131
#define NOTE_CS3 139
#define NOTE_D3 147
#define NOTE_DS3 156
#define NOTE_E3 165
#define NOTE_F3 175
#define NOTE_FS3 185
#define NOTE_G3 196
#define NOTE_GS3 208
#define NOTE_A3 220
#define NOTE_AS3 233
#define NOTE_B3 247
#define NOTE_C4 262
#define NOTE_CS4 277
#define NOTE_D4 294
#define NOTE_DS4 311
#define NOTE_E4 330
#define NOTE_F4 349
#define NOTE_FS4 370
#define NOTE_G4 392
#define NOTE_GS4 415
#define NOTE_A4 440
#define NOTE_AS4 466
#define NOTE_B4 494
#define NOTE_C5 523
#define NOTE_CS5 554
#define NOTE_D5 587
#define NOTE_DS5 622
#define NOTE_E5 659
#define NOTE_F5 698
#define NOTE_FS5 740
#define NOTE_G5 784
#define NOTE_GS5 831
#define NOTE_A5 880
#define NOTE_AS5 932
#define NOTE_B5 988
#define NOTE_C6 1047
#define NOTE_CS6 1109
#define NOTE_D6 1175
#define NOTE_DS6 1245
#define NOTE_E6 1319
#define NOTE_F6 1397
#define NOTE_FS6 1480
#define NOTE_G6 1568
#define NOTE_GS6 1661
#define NOTE_A6 1760
#define NOTE_AS6 1865
#define NOTE_B6 1976
#define NOTE_C7 2093
#define NOTE_CS7 2217
#define NOTE_D7 2349
#define NOTE_DS7 2489
#define NOTE_E7 2637
#define NOTE_F7 2794
#define NOTE_FS7 2960
#define NOTE_G7 3136
#define NOTE_GS7 3322
#define NOTE_A7 3520
#define NOTE_AS7 3729
#define NOTE_B7 3951
#define NOTE_C8 4186
#define NOTE_CS8 4435
#define NOTE_D8 4699
#define NOTE_DS8 4978
Demo video
Future Extensions
The main thing that i wish i had time for was LEDs. I wanted to put three LEDs on each side of the box and have them light up when a button is pressed. I even had this working for one button but I did not have enough time for the rest, so i decided to get rid of that single button and leave this idea as a future extension. Another thing that i would like to do is amplify the sound.
Comments (1)
Jessica Faruque said
at 4:35 pm on Aug 20, 2013
It is great to hear about how you ended up picking an 8-bit piano for your final project! We enjoyed hearing about how you formulated a concept because you were reminded by something else you liked -- i.e. Benjamin William's spy gear. We really like how you have a clear definition of your audience as DJ's that like to experiment with electronic sounds.
Your Verplanck diagram and paper prototypes are great to see. We liked how you made a prototype that was quick and easy to build, so that you could refine and iterate quickly on your concept. We liked how you mentioned your design considerations such as simplicity, and wish we could see more discussion of that.
We liked your prototype photo. We wish you had incorporated more description of what each of the components of your prototype are, so future students and viewers unfamiliar with your system could better understand what it was doing. We also liked your state diagram, and liked the simplicity that you used in your design. We wish you had provided some captions for your state diagram so as to make it more clear to understand.
We also wish that you had more description of the challenges you faced in making this project. This would be great for future students to know, so that they are better able to solve problems and avoid any pitfalls you faced.
Your demo video was great, and provided a good overview of everything that your player could do. We really enjoyed how your final prototype came together!
This was a great project, and we hope that you will be able to put it on a perfboard someday. We hope you had fun in EE47!
- Jessica, David, Vivien, Matt, Kevin
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