esp32 tone

[gemforce]

Hi
Why not working tone in esp32 ?

   tone(SOUND_PIN, 1000, 1000);
   delay(1000);
    noTone(SOUND_PIN)

[lbernstone]

I think tone() will be implemented in the ESP-IDF, rather than arduino. In the meantime, try https://techtutorialsx.com/2017/07/01/esp32-arduino-controlling-a-buzzer-with-pwm/

[ReanimationXP]

This is part of the Arduino core library and needs to be implemented, as it causes the basic Examples > Digital > toneMelody example to not compile correctly.

[lbernstone]

I don't think this is of a quality to be added to the code base, but it is a start, anyhow.
https://github.com/lbernstone/Tone

[Thomascountz]

Although this functionality is unavailable in Espressif's arduino-esp32 library, members of the community have found various work-arounds such as using the native LED Control functions to generate PWM signals.

However, looking more closely at arduino-esp32 library, not only has Espressif provided a clean API for generating tones, they've provided an interface for generating specific PWM frequencies for specific notes on the chromatic scale in different octaves.

https://github.com/espressif/arduino-esp32/blob/master/cores/esp32/esp32-hal-ledc.c#L255-L266

double ledcWriteNote(uint8_t chan, note_t note, uint8_t octave){
  const uint16_t noteFrequencyBase[12] = {
  //   C        C#       D        Eb       E        F       F#        G       G#        A       Bb        B
      4186,    4435,    4699,    4978,    5274,    5588,    5920,    6272,    6645,    7040,    7459,    7902
  };

  if(octave > 8 || note >= NOTE_MAX){
      return 0;
  }
  double noteFreq =  (double)noteFrequencyBase[note] / (double)(1 << (8-octave));
  return ledcWriteTone(chan, noteFreq);
}

Although not directly compatible with Arduino's tone(), the function allows for a clearer interface by providing named frequencies out of the box via the note_t type.

typedef enum {
    NOTE_C, NOTE_Cs, NOTE_D, NOTE_Eb, NOTE_E, NOTE_F, NOTE_Fs, NOTE_G, NOTE_Gs, NOTE_A, NOTE_Bb, NOTE_B, NOTE_MAX
} note_t;

Example Usage

Here is an example of generating PWM frequencies at 50% duty cycle to play the C-major scale.

void playScale(uint8_t pin, uint8_t channel) {
  ledcAttachPin(pin, channel);
  ledcWriteNote(pin, NOTE_C, 4);
  delay(500);
  ledcWriteNote(pin, NOTE_D, 4);
  delay(500);
  ledcWriteNote(pin, NOTE_E, 4);
  delay(500);
  ledcWriteNote(pin, NOTE_F, 4);
  delay(500);
  ledcWriteNote(pin, NOTE_G, 4);
  delay(500);
  ledcWriteNote(pin, NOTE_A, 4);
  delay(500);
  ledcWriteNote(pin, NOTE_B, 4);
  delay(500);
  ledcDetachPin(pin)
}

[lbernstone]

analogWrite and tone are both available in the ESP32Servo library. This can be found in the Arduino Library Manager.

[mmackh]

For anyone coming across @Thomascountz Example Usage code, the first argument in ledcWriteNote is a channel, not the pin. So the code could look like:

void playScale(uint8_t pin, uint8_t channel) {
  uint8_t octave = 4;
  
  ledcAttachPin(pin, channel);
  ledcWriteNote(channel, NOTE_C, octave);
  delay(500);
  ledcWriteNote(channel, NOTE_D, octave);
  delay(500);
  ledcWriteNote(channel, NOTE_E, octave);
  delay(500);
  ledcWriteNote(channel, NOTE_F, octave);
  delay(500);
  ledcWriteNote(channel, NOTE_G, octave);
  delay(500);
  ledcWriteNote(channel, NOTE_A, octave);
  delay(500);
  ledcWriteNote(channel, NOTE_B, octave);
  delay(500);
  ledcDetachPin(pin);
}

[aldityarafi]

analogWrite and tone are both available in the ESP32Servo library. This can be found in the Arduino Library Manager.

hey man, you just saved me from depression because of this...buzzer . Thanks