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e99df4fe1a
Fixes #427 Adds a basic I2S class based off of the Arduino-SAMD core. The raw i2s_xxx functions are still a better way to use I2S due to their flexibility, but this will allow basic Arduino sketches to work.
47 lines
1.2 KiB
C++
47 lines
1.2 KiB
C++
/*
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This example generates a square wave based tone at a specified frequency
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and sample rate. Then outputs the data using the I2S interface to a
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MAX08357 I2S Amp Breakout board.
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created 17 November 2016
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by Sandeep Mistry
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modified for ESP8266 by Earle F. Philhower, III <earlephilhower@yahoo.com>
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*/
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#include <I2S.h>
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const int frequency = 440; // frequency of square wave in Hz
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const int amplitude = 500; // amplitude of square wave
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const int sampleRate = 8000; // sample rate in Hz
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const int halfWavelength = (sampleRate / frequency); // half wavelength of square wave
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short sample = amplitude; // current sample value
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int count = 0;
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void setup() {
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Serial.begin(115200);
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Serial.println("I2S simple tone");
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// start I2S at the sample rate with 16-bits per sample
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if (!I2S.begin(I2S_PHILIPS_MODE, sampleRate, 16)) {
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Serial.println("Failed to initialize I2S!");
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while (1); // do nothing
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}
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}
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void loop() {
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if (count % halfWavelength == 0) {
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// invert the sample every half wavelength count multiple to generate square wave
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sample = -1 * sample;
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}
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// write the same sample twice, once for left and once for the right channel
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I2S.write(sample);
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I2S.write(sample);
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// increment the counter for the next sample
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count++;
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}
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