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Commit 590eaec

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Merge branch 'main' into rtc-example-simplified
2 parents 1ef7d0d + a086f96 commit 590eaec

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/*
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Plays a tone in response to a potentiometer
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formula from https://newt.phys.unsw.edu.au/jw/notes.html
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and https://en.wikipedia.org/wiki/MIDI_tuning_standard:
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the MIDI protocol divides the notes of an equal-tempered scale into
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128 possible note values. Middle A is MIDI note value 69. There is
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a formula for converting MIDI note numbers (0-127) to pitches. This sketch
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reduces that to the notes 21 - 108, which are the 88 keys found on a piano:
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frequency = 440 * ((noteNumber - 69) / 12.0)^2
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You can see this applied in the code below.
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circuit:
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* audio amp (LM386 used for testing) input+ attached to A0
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* audio amp input- attached to ground
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* 4-8-ohm speaker attached to amp output+
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* Potentiometer connected to pin A5
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created 18 Dec 2018
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modified 3 Jul 2023
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by Tom Igoe
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*/
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// include the AnalogWave library:
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#include "analogWave.h"
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analogWave wave(DAC);
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// middle A is the reference frequency for an
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// equal-tempered scale. Set its frequency and note value:
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#define NOTE_A4 69 // MIDI note value for middle A
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#define FREQ_A4 440 // frequency for middle A
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const int speakerPin = A0; // the pin number for the speaker
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void setup() {
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Serial.begin(9600);
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wave.sine(10);
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}
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void loop() {
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// convert sensor reading to 21 - 108 range
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// which is the range of MIDI notes on an 88-key keyboard
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// (from A0 to C8):
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int sensorReading = analogRead(A5);
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int noteValue = map(sensorReading, 0, 1023, 21, 108);
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// then convert to frequency:
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float frequency = FREQ_A4 * pow(2, ((noteValue - NOTE_A4) / 12.0));
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int freq = int(frequency);
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// turn the speaker on:
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wave.freq(freq);
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Serial.print("note value: "+ String(noteValue) + " freq: ");
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Serial.println(freq);
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delay(500);
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}
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/*
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DAC Melody player
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Generates a series of tones from MIDI note values
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using the Uno R4 DAC and the AnalogWave Library.
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The melody is "Frere Jacques"
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circuit:
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* audio amp (LM386 used for testing) input+ attached to A0
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* audio amp input- attached to ground
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* 4-8-ohm speaker attached to amp output+
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* Potentiometer connected to pin A5
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created 13 Feb 2017
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modified 3 Jul 2023
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by Tom Igoe
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*/
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#include "analogWave.h"
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analogWave wave(DAC);
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#define NOTE_A4 69 // MIDI note value for middle A
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#define FREQ_A4 440 // frequency for middle A
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// the tonic, or first note of the key signature for the song:
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int tonic = 65;
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// the melody sequence. Note values are relative to the tonic:
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int melody[] = {1, 3, 5, 1,
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1, 3, 5, 1,
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5, 6, 8, 5, 6, 8,
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8, 10, 8, 6, 5, 1,
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8, 10, 8, 6, 5, 1,
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1, -4, 1,
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1, -4, 1
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};
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// the rhythm sequence. Values are 1/note, e.g. 4 = 1/4 note:
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int rhythm[] = {4, 4, 4, 4,
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4, 4, 4, 4,
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4, 4, 2,
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4, 4, 2,
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8, 8, 8, 8, 4, 4,
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8, 8, 8, 8, 4, 4,
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4, 4, 2,
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4, 4, 2
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};
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// which note of the melody to play:
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int noteCounter = 0;
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int bpm = 120; // beats per minute
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// duration of a beat in ms
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float beatDuration = 60.0 / bpm * 1000;
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void setup() {
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// start the sine wave generator:
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wave.sine(10);
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}
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void loop() {
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// current note is an element of the array:
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int currentNote = melody[noteCounter] + tonic;
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// play a note from the melody:
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// convert MIDI note number to frequency:
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float frequency = FREQ_A4 * pow(2, ((currentNote - NOTE_A4) / 12.0));
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// all the notes in this are sixteenth notes,
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// which is 1/4 of a beat, so:
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float noteDuration = beatDuration * (4.0 / rhythm[noteCounter]);
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// turn the note on:
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wave.freq(frequency);
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// tone(speakerPin, frequency, noteDuration * 0.85);
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// keep it on for the appropriate duration:
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delay(noteDuration * 0.85);
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wave.stop();
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delay(noteDuration * 0.15);
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// turn the note off:
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// noTone(speakerPin);
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// increment the note number for next time through the loop:
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noteCounter++;
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// keep the note in the range from 0 - 32 using modulo:
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noteCounter = noteCounter % 32;
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}

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