chip

tech

sound frequency

const int frequency = 600;    // Frequency of the square wave in Hz (600 cycles per second)
const int amplitude = 500;    // Amplitude of the square wave (controls loudness)
const int sampleRate = 4000;  // Sample rate in Hz (samples per second for accurate waveform)

Frequency (440 Hz):

  • 440 Hz is a standard musical note (A4), which is very clear and noticeable to human ears.
  • It’s neither too low nor too high, making it a great choice for testing.

Sample Rate (8000 Hz):

  • The sample rate should be at least twice the frequency (Nyquist theorem). For 440 Hz, 8000 Hz ensures clear sound.
  • It’s also lightweight for the ESP32 to process, leaving room for other tasks.

Amplitude Tuning:

If 500 is too quiet, you can increase the amplitude up to 32767 (maximum for 16-bit audio). Different Frequencies: If you'd like to test other audible frequencies, try values like:

  • 523 Hz (C5) – A clear and bright tone.
  • 880 Hz (A5) – A higher-pitched tone.
  • 262 Hz (C4) – A lower-pitched tone.

SCH

wiring to D1-dat - F133-dat

SCH2

code library

analog audio SCH

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