@@ -24,10 +24,17 @@
 2nd September 2021
 Lucas Saavedra Vaz (lucasssvaz)
 22nd December 2023
+anon
+10nd February 2025
 */
 
 #include <ESP_I2S.h>
 
+// The GPIO pins are not fixed, most other pins could be used for the I2S function.
+#define I2S_LRC 25
+#define I2S_BCLK 5
+#define I2S_DIN 26
+
 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
@@ -36,17 +43,19 @@ i2s_data_bit_width_t bps = I2S_DATA_BIT_WIDTH_16BIT;
 i2s_mode_t mode = I2S_MODE_STD;
 i2s_slot_mode_t slot = I2S_SLOT_MODE_STEREO;
 
-const int halfWavelength = (sampleRate / frequency); // half wavelength of square wave
+const unsigned int halfWavelength = sampleRate / frequency / 2; // half wavelength of square wave
 
 int32_t sample = amplitude; // current sample value
-int count = 0;
+unsigned int count = 0;
 
 I2SClass i2s;
 
 void setup() {
 Serial.begin(115200);
 Serial.println("I2S simple tone");
 
+i2s.setPins(I2S_BCLK, I2S_LRC, I2S_DIN);
+
 // start I2S at the sample rate with 16-bits per sample
 if (!i2s.begin(mode, sampleRate, bps, slot)) {
 Serial.println("Failed to initialize I2S!");
@@ -60,8 +69,13 @@ void loop() {
 sample = -1 * sample;
 }
 
-i2s.write(sample); // Right channel
-i2s.write(sample); // Left channel
+// Left channel, the low 8 bits then high 8 bits
+i2s.write(sample);
+i2s.write(sample >> 8);
+
+// Right channel, the low 8 bits then high 8 bits
+i2s.write(sample);
+i2s.write(sample >> 8);
 
 // increment the counter for the next sample
 count++;