This lab was all about analog inputs. Analog Out: Pulse width modulation (PWM) vs frequency output (tone)
We started off by doing our handy dandy sensor check and by checking what the values are. This is actually an invaluable tactic because it's a solid check on if you're getting the values you're expecting.
// Sensor Check
void setup() {
Serial.begin(9600); // initialize serial communications
}
void loop() {
int analogValue = analogRead(A0); // read the analog input
Serial.println(analogValue); // print it
}
Then we checked if our speaker was wired up correctly and soldered the right way by sending it a basic tone command.
// Speaker Check
void setup() {
// nothing to do here
}
void loop() {
// play the tone for 1 second:
tone(8, 440,1000);
// do nothing else for the one second you're playing:
delay(1000);
}
Figure 1: A circuit with a force sensor and a speaker
Then by writing some Arduino code we were able to connect the force sensor to the speaker and have the frequency change by pressing harder on the sensor.
// Change the frequency of the speaker with the force sensor
void setup() {
Serial.begin(9600); // initialize serial communications
}
void loop() {
// get a sensor reading:
int sensorReading = analogRead(A0);
// map the results from the sensor reading's range
// // to the desired pitch range:
float frequency = map(sensorReading, 0, 1000, 100, 1000);
Serial.println(frequency);
// // change the pitch, play for 10 ms:
tone(8, frequency, 10);
delay(10);
}
Using some code I found online, I was able to play the Mii soundtrack from Wii by creating a melody.
// The code to play the mii soundtrack
#include "pitches.h"
// change this to make the song slower or faster
int tempo = 114;
// change this to whichever pin you want to use
int buzzer = 11;
// notes of the moledy followed by the duration.
// a 4 means a quarter note, 8 an eighteenth , 16 sixteenth, so on
// !!negative numbers are used to represent dotted notes,
// so -4 means a dotted quarter note, that is, a quarter plus an eighteenth!!
int melody[] = {
// Mii Channel theme
// Score available at <https://musescore.com/user/16403456/scores/4984153>
// Uploaded by Catalina Andrade
NOTE_FS4,8, REST,8, NOTE_A4,8, NOTE_CS5,8, REST,8,NOTE_A4,8, REST,8, NOTE_FS4,8, //1
NOTE_D4,8, NOTE_D4,8, NOTE_D4,8, REST,8, REST,4, REST,8, NOTE_CS4,8,
NOTE_D4,8, NOTE_FS4,8, NOTE_A4,8, NOTE_CS5,8, REST,8, NOTE_A4,8, REST,8, NOTE_F4,8,
NOTE_E5,-4, NOTE_DS5,8, NOTE_D5,8, REST,8, REST,4,
NOTE_GS4,8, REST,8, NOTE_CS5,8, NOTE_FS4,8, REST,8,NOTE_CS5,8, REST,8, NOTE_GS4,8, //5
REST,8, NOTE_CS5,8, NOTE_G4,8, NOTE_FS4,8, REST,8, NOTE_E4,8, REST,8,
NOTE_E4,8, NOTE_E4,8, NOTE_E4,8, REST,8, REST,4, NOTE_E4,8, NOTE_E4,8,
NOTE_E4,8, REST,8, REST,4, NOTE_DS4,8, NOTE_D4,8,
NOTE_CS4,8, REST,8, NOTE_A4,8, NOTE_CS5,8, REST,8,NOTE_A4,8, REST,8, NOTE_FS4,8, //9
NOTE_D4,8, NOTE_D4,8, NOTE_D4,8, REST,8, NOTE_E5,8, NOTE_E5,8, NOTE_E5,8, REST,8,
REST,8, NOTE_FS4,8, NOTE_A4,8, NOTE_CS5,8, REST,8, NOTE_A4,8, REST,8, NOTE_F4,8,
NOTE_E5,2, NOTE_D5,8, REST,8, REST,4,
NOTE_B4,8, NOTE_G4,8, NOTE_D4,8, NOTE_CS4,4, NOTE_B4,8, NOTE_G4,8, NOTE_CS4,8, //13
NOTE_A4,8, NOTE_FS4,8, NOTE_C4,8, NOTE_B3,4, NOTE_F4,8, NOTE_D4,8, NOTE_B3,8,
NOTE_E4,8, NOTE_E4,8, NOTE_E4,8, REST,4, REST,4, NOTE_AS4,4,
NOTE_CS5,8, NOTE_D5,8, NOTE_FS5,8, NOTE_A5,8, REST,8, REST,4,
REST,2, NOTE_A3,4, NOTE_AS3,4, //17
NOTE_A3,-4, NOTE_A3,8, NOTE_A3,2,
REST,4, NOTE_A3,8, NOTE_AS3,8, NOTE_A3,8, NOTE_F4,4, NOTE_C4,8,
NOTE_A3,-4, NOTE_A3,8, NOTE_A3,2,
REST,2, NOTE_B3,4, NOTE_C4,4, //21
NOTE_CS4,-4, NOTE_C4,8, NOTE_CS4,2,
REST,4, NOTE_CS4,8, NOTE_C4,8, NOTE_CS4,8, NOTE_GS4,4, NOTE_DS4,8,
NOTE_CS4,-4, NOTE_DS4,8, NOTE_B3,1,
NOTE_E4,4, NOTE_E4,4, NOTE_E4,4, REST,8,//25
//repeats 1-25
NOTE_FS4,8, REST,8, NOTE_A4,8, NOTE_CS5,8, REST,8,NOTE_A4,8, REST,8, NOTE_FS4,8, //1
NOTE_D4,8, NOTE_D4,8, NOTE_D4,8, REST,8, REST,4, REST,8, NOTE_CS4,8,
NOTE_D4,8, NOTE_FS4,8, NOTE_A4,8, NOTE_CS5,8, REST,8, NOTE_A4,8, REST,8, NOTE_F4,8,
NOTE_E5,-4, NOTE_DS5,8, NOTE_D5,8, REST,8, REST,4,
NOTE_GS4,8, REST,8, NOTE_CS5,8, NOTE_FS4,8, REST,8,NOTE_CS5,8, REST,8, NOTE_GS4,8, //5
REST,8, NOTE_CS5,8, NOTE_G4,8, NOTE_FS4,8, REST,8, NOTE_E4,8, REST,8,
NOTE_E4,8, NOTE_E4,8, NOTE_E4,8, REST,8, REST,4, NOTE_E4,8, NOTE_E4,8,
NOTE_E4,8, REST,8, REST,4, NOTE_DS4,8, NOTE_D4,8,
NOTE_CS4,8, REST,8, NOTE_A4,8, NOTE_CS5,8, REST,8,NOTE_A4,8, REST,8, NOTE_FS4,8, //9
NOTE_D4,8, NOTE_D4,8, NOTE_D4,8, REST,8, NOTE_E5,8, NOTE_E5,8, NOTE_E5,8, REST,8,
REST,8, NOTE_FS4,8, NOTE_A4,8, NOTE_CS5,8, REST,8, NOTE_A4,8, REST,8, NOTE_F4,8,
NOTE_E5,2, NOTE_D5,8, REST,8, REST,4,
NOTE_B4,8, NOTE_G4,8, NOTE_D4,8, NOTE_CS4,4, NOTE_B4,8, NOTE_G4,8, NOTE_CS4,8, //13
NOTE_A4,8, NOTE_FS4,8, NOTE_C4,8, NOTE_B3,4, NOTE_F4,8, NOTE_D4,8, NOTE_B3,8,
NOTE_E4,8, NOTE_E4,8, NOTE_E4,8, REST,4, REST,4, NOTE_AS4,4,
NOTE_CS5,8, NOTE_D5,8, NOTE_FS5,8, NOTE_A5,8, REST,8, REST,4,
REST,2, NOTE_A3,4, NOTE_AS3,4, //17
NOTE_A3,-4, NOTE_A3,8, NOTE_A3,2,
REST,4, NOTE_A3,8, NOTE_AS3,8, NOTE_A3,8, NOTE_F4,4, NOTE_C4,8,
NOTE_A3,-4, NOTE_A3,8, NOTE_A3,2,
REST,2, NOTE_B3,4, NOTE_C4,4, //21
NOTE_CS4,-4, NOTE_C4,8, NOTE_CS4,2,
REST,4, NOTE_CS4,8, NOTE_C4,8, NOTE_CS4,8, NOTE_GS4,4, NOTE_DS4,8,
NOTE_CS4,-4, NOTE_DS4,8, NOTE_B3,1,
NOTE_E4,4, NOTE_E4,4, NOTE_E4,4, REST,8,//25
//finishes with 26
//NOTE_FS4,8, REST,8, NOTE_A4,8, NOTE_CS5,8, REST,8, NOTE_A4,8, REST,8, NOTE_FS4,8
};
// sizeof gives the number of bytes, each int value is composed of two bytes (16 bits)
// there are two values per note (pitch and duration), so for each note there are four bytes
int notes = sizeof(melody) / sizeof(melody[0]) / 2;
// this calculates the duration of a whole note in ms
int wholenote = (60000 * 4) / tempo;
int divider = 0, noteDuration = 0;
void setup() {
// iterate over the notes of the melody.
// Remember, the array is twice the number of notes (notes + durations)
for (int thisNote = 0; thisNote < notes * 2; thisNote = thisNote + 2) {
// calculates the duration of each note
divider = melody[thisNote + 1];
if (divider > 0) {
// regular note, just proceed
noteDuration = (wholenote) / divider;
} else if (divider < 0) {
// dotted notes are represented with negative durations!!
noteDuration = (wholenote) / abs(divider);
noteDuration *= 1.5; // increases the duration in half for dotted notes
}
// we only play the note for 90% of the duration, leaving 10% as a pause
tone(buzzer, melody[thisNote], noteDuration*0.9);
// Wait for the specief duration before playing the next note.
delay(noteDuration);
// stop the waveform generation before the next note.
noTone(buzzer);
}
}
void loop() {
// no need to repeat the melody.
}
After this we ended up connecting 3 pressure sensors to our circuit and mapped them to notes so we made a really bad keyboard.
#include "pitches.h"
const int threshold = 10; // minimum reading of the sensors that generates a note
const int speakerPin = 8; // pin number for the speaker
const int noteDuration = 20; // play notes for 20 ms
// notes to play, corresponding to the 3 sensors:
int notes[] = {
NOTE_A4, NOTE_B4,NOTE_C3 };
void setup() {
}
void loop() {
for (int thisSensor = 0; thisSensor < 3; thisSensor++) {
// get a sensor reading:
int sensorReading = analogRead(thisSensor);
// if the sensor is pressed hard enough:
if (sensorReading > threshold) {
// play the note corresponding to this sensor:
tone(speakerPin, notes[thisSensor], noteDuration);
}
}
}
Figure 3: Bad keyboard playing with some force sensors.
Next up was controlling a servo motor, by mapping the servo controller to the force sensor we could move our servo to a specific angle.
#include "Servo.h" // include the servo library
Servo servoMotor; // creates an instance of the servo object to control a servo
int servoPin = 3; // Control pin for servo motor
void setup() {
Serial.begin(9600); // initialize serial communications
servoMotor.attach(servoPin); // attaches the servo on pin 3 to the servo object
}
void loop()
{
int analogValue = analogRead(A0); // read the analog input
Serial.println(analogValue); // print it
// if your sensor's range is less than 0 to 1023, you'll need to
// modify the map() function to use the values you discovered:
int servoAngle = map(analogValue, 0, 1023, 0, 179);
// move the servo using the angle from the sensor:
servoMotor.write(servoAngle);
}
Figure 4: The buff o meter tests how strong you are by mapping a force sensors output to a servo