A (Psuedo) Theremin

1#include <LiquidCrystal.h>
2
3const int RS = 8;
4const int E = 9;
5const int DB4 = 10;
6const int DB5 = 11;
7const int DB6 = 12;
8const int DB7 = 13;
9
10auto lcd = LiquidCrystal(RS, E, DB4, DB5, DB6, DB7);
11
12const int PITCH_SENSOR_ECHO = 4;
13const int PITCH_SENSOR_TRIG = 5;
14
15long pitch_time;
16short pitch_distance;
17int pitch;
18
19const int SPEAKER = 6;
20
21const int LAG = 65;
22
23void setup()
24{
25  Serial.begin(9600);
26
27  pinMode(PITCH_SENSOR_TRIG, OUTPUT);
28  pinMode(PITCH_SENSOR_ECHO, INPUT);
29  
30  pinMode(SPEAKER, OUTPUT);
31  
32  lcd.begin(16,2);
33  lcd.setCursor(0,0);
34  lcd.print("Pitch: ");
35}
36
37void loop()
38{
39
40  //Calls a function to sense the distance (in time) to an object and stores it
41  pitch_time = senseDistance(PITCH_SENSOR_TRIG, PITCH_SENSOR_ECHO);
42  
43  //Uses the time to calculate the distance in cm
44  pitch_distance = pitch_time / 58;
45  
46  //Map the distance to the frequencies that you want to output
47  pitch = map(pitch_distance, 0, 355, 131, 523);
48
49  lcdDisplay(pitch);
50
51  tone(SPEAKER, pitch, 60);
52  
53  delay(LAG);
54}
55
56//Function to sense distance
57long senseDistance(int triggerSensor, int echoSensor) {
58  
59  digitalWrite(triggerSensor, HIGH);
60  delayMicroseconds(10);
61  digitalWrite(triggerSensor, LOW);
62  
63  return pulseIn(echoSensor, HIGH);
64}
65
66//Function to output a display
67void lcdDisplay(int pitch) {
68  lcd.setCursor(7, 0);
69  lcd.print(pitch);
70  lcd.print("Hz    ");
71  
72}