Prvni ulozeni z chegewara githubu

libraries/I2S/examples/SimpleTone/SimpleTone.ino

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+/*
+ This example generates a square wave based tone at a specified frequency
+ and sample rate. Then outputs the data using the I2S interface to a
+ MAX08357 I2S Amp Breakout board.
+
+ I2S Circuit:
+ * Arduino/Genuino Zero, MKR family and Nano 33 IoT
+ * MAX08357:
+   * GND connected GND
+   * VIN connected 5V
+   * LRC connected to pin 0 (Zero) or 3 (MKR), A2 (Nano) or 25 (ESP32)
+   * BCLK connected to pin 1 (Zero) or 2 (MKR), A3 (Nano) or 5 (ESP32)
+   * DIN connected to pin 9 (Zero) or A6 (MKR), 4 (Nano) or 26 (ESP32)
+
+ DAC Circuit:
+ * ESP32 or ESP32-S2
+ * Audio amplifier
+   - Note:
+     - ESP32 has DAC on GPIO pins 25 and 26.
+     - ESP32-S2 has DAC on GPIO pins 17 and 18.
+  - Connect speaker(s) or headphones.
+
+ created 17 November 2016
+ by Sandeep Mistry
+ For ESP extended
+ Tomas Pilny
+ 2nd September 2021
+ */
+
+#include <I2S.h>
+const int frequency = 440; // frequency of square wave in Hz
+const int amplitude = 500; // amplitude of square wave
+const int sampleRate = 8000; // sample rate in Hz
+const int bps = 16;
+
+const int halfWavelength = (sampleRate / frequency); // half wavelength of square wave
+
+short sample = amplitude; // current sample value
+int count = 0;
+
+i2s_mode_t mode = I2S_PHILIPS_MODE; // I2S decoder is needed
+// i2s_mode_t mode = ADC_DAC_MODE; // Audio amplifier is needed
+
+// Mono channel input
+// This is ESP specific implementation -
+//   samples will be automatically copied to both channels inside I2S driver
+//   If you want to have true mono output use I2S_PHILIPS_MODE and interlay
+//   second channel with 0-value samples.
+//   The order of channels is RIGH followed by LEFT
+//i2s_mode_t mode = I2S_RIGHT_JUSTIFIED_MODE; // I2S decoder is needed
+
+void setup() {
+  Serial.begin(115200);
+  Serial.println("I2S simple tone");
+
+  // start I2S at the sample rate with 16-bits per sample
+  if (!I2S.begin(mode, sampleRate, bps)) {
+    Serial.println("Failed to initialize I2S!");
+    while (1); // do nothing
+  }
+}
+
+void loop() {
+    if (count % halfWavelength == 0 ) {
+      // invert the sample every half wavelength count multiple to generate square wave
+      sample = -1 * sample;
+    }
+
+    if(mode == I2S_PHILIPS_MODE || mode == ADC_DAC_MODE){ // write the same sample twice, once for Right and once for Left channel
+      I2S.write(sample); // Right channel
+      I2S.write(sample); // Left channel
+    }else if(mode == I2S_RIGHT_JUSTIFIED_MODE || mode == I2S_LEFT_JUSTIFIED_MODE){
+      // write the same only once - it will be automatically copied to the other channel
+      I2S.write(sample);
+    }
+
+    // increment the counter for the next sample
+    count++;
+}