Arduino UNO R4 Minima Digital-to-Analog Converter (DAC)

Copy
1/*
2  SineWave
3
4  Generates a pre-generated sawtooth-waveform.
5
6  See the full documentation here:
7  https://docs.arduino.cc/tutorials/uno-r4-wifi/dac
8*/
9
10#include "analogWave.h" // Include the library for analog waveform generation
11
12analogWave wave(DAC);   // Create an instance of the analogWave class, using the DAC pin
13
14int freq = 10;  // in hertz, change accordingly
15
16void setup() {
17  Serial.begin(115200);  // Initialize serial communication at a baud rate of 115200
18  wave.sine(freq);       // Generate a sine wave with the initial frequency
19}
20
21void loop() {
22  // Read an analog value from pin A5 and map it to a frequency range
23  freq = map(analogRead(A5), 0, 1024, 0, 10000);
24
25  // Print the updated frequency to the serial monitor
26  Serial.println("Frequency is now " + String(freq) + " hz");
27
28  wave.freq(freq);  // Set the frequency of the waveform generator to the updated value
29  delay(1000);      // Delay for one second before repeating
30}

Copy
1wave.square(freq);

Copy
1wave.saw(freq);

Copy
1/*
2  DAC Melody player
3
4  Generates a series of tones from MIDI note values
5  using the Uno R4 DAC and the AnalogWave Library.
6   The melody is "Frere Jacques"
7
8circuit:
9     * audio amp (LM386 used for testing) input+ attached to A0
10     * audio amp input- attached to ground
11     * 4-8-ohm speaker attached to amp output+
12     * Potentiometer connected to pin A5
13
14  created 13 Feb 2017
15  modified 3 Jul 2023
16  by Tom Igoe
17
18  See the full documentation here:
19  https://docs.arduino.cc/tutorials/uno-r4-wifi/dac
20*/
21#include "analogWave.h"
22analogWave wave(DAC);
23
24#define NOTE_A4 69         // MIDI note value for middle A
25#define FREQ_A4 440        // frequency for middle A
26
27// the tonic, or first note of the key signature for the song:
28int tonic = 65;
29// the melody sequence. Note values are relative to the tonic:
30int melody[] = {1, 3, 5, 1,
31                1, 3, 5, 1,
32                5, 6, 8, 5, 6, 8,
33                8, 10, 8, 6, 5, 1,
34                8, 10, 8, 6, 5, 1,
35                1, -4, 1,
36                1, -4, 1
37               };
38// the rhythm sequence. Values are 1/note, e.g. 4 = 1/4 note:
39int rhythm[] = {4, 4, 4, 4,
40                4, 4, 4, 4,
41                4, 4, 2,
42                4, 4, 2,
43                8, 8, 8, 8, 4, 4,
44                8, 8, 8, 8, 4, 4,
45                4, 4, 2,
46                4, 4, 2
47               };
48// which note of the melody to play:
49int noteCounter = 0;
50
51int bpm = 120;  // beats per minute
52// duration of a beat in ms
53float beatDuration = 60.0 / bpm * 1000;
54
55void setup() {
56// start the sine wave generator:
57  wave.sine(10);
58}
59
60void loop() {
61  // current note is an element of the array:
62  int currentNote = melody[noteCounter] + tonic;
63  // play a note from the melody:
64  // convert MIDI note number to frequency:
65  float frequency =  FREQ_A4 * pow(2, ((currentNote - NOTE_A4) / 12.0));
66
67  // all the notes in this are sixteenth notes,
68  // which is 1/4 of a beat, so:
69  float noteDuration = beatDuration * (4.0 / rhythm[noteCounter]);
70  // turn the note on:
71  wave.freq(frequency);
72 // tone(speakerPin, frequency, noteDuration * 0.85);
73  // keep it on for the appropriate duration:
74  delay(noteDuration * 0.85);
75  wave.stop();
76  delay(noteDuration * 0.15);
77  // turn the note off:
78 // noTone(speakerPin);
79  // increment the note number for next time through the loop:
80  noteCounter++;
81  // keep the note in the range from 0 - 32 using modulo:
82  noteCounter = noteCounter % 32;
83
84}
85

Copy
1/*
2  Plays a tone in response to a potentiometer
3  formula from https://newt.phys.unsw.edu.au/jw/notes.html
4  and https://en.wikipedia.org/wiki/MIDI_tuning_standard:
5
6  the MIDI protocol divides the notes of an equal-tempered scale into 
7  128 possible note values. Middle A is MIDI note value 69. There is
8  a formula for converting MIDI note numbers (0-127) to pitches. This sketch
9  reduces that to the notes 21 - 108, which are the 88 keys found on a piano:
10
11     frequency =  440 * 2^((noteNumber - 69) / 12.0)
12
13  You can see this applied in the code below. 
14
15  circuit:
16     * audio amp (LM386 used for testing) input+ attached to A0
17     * audio amp input- attached to ground
18     * 4-8-ohm speaker attached to amp output+
19     * Potentiometer connected to pin A5
20
21   created 18 Dec 2018
22   modified 3 Jul 2023
23   by Tom Igoe
24
25  See the full documentation here:
26  https://docs.arduino.cc/tutorials/uno-r4-wifi/dac
27*/
28
29// include the AnalogWave library:
30#include "analogWave.h"
31analogWave wave(DAC);
32
33// middle A is the reference frequency for an
34// equal-tempered scale. Set its frequency and note value:
35#define NOTE_A4 69         // MIDI note value for middle A
36#define FREQ_A4 440        // frequency for middle A
37
38const int speakerPin = A0;  // the pin number for the speaker
39void setup() {
40  Serial.begin(9600);
41  wave.sine(10);
42}
43void loop() {
44  // convert sensor reading to 21 - 108 range
45  // which is the range of MIDI notes on an 88-key keyboard
46  // (from A0 to C8):
47  int sensorReading = analogRead(A5);
48  int noteValue = map(sensorReading, 0, 1023, 21, 108);
49  // then convert to frequency:
50  float frequency =  FREQ_A4 * pow(2, ((noteValue - NOTE_A4) / 12.0));
51  int freq = int(frequency);
52  // turn the speaker on:
53  wave.freq(freq);
54  Serial.print("note value: "+ String(noteValue) + " freq: ");
55  Serial.println(freq);
56  delay(500);
57}
58