this fix #13

@ryanhz Hi. How did you come up about macro ARDUINO_ESP32_MAJOR ? I am searching multiple locations and I cannot find a reference about to this macro. I've installed esp32 core v3.3.1 and this macro do not seems to be resolving properly.
I am expecting to have this macro available.

If I compile the following code on esp32:esp32:

#if defined(ESP32)
  #if ARDUINO_ESP32_MAJOR >= 3
    aaa
  #elif ARDUINO_ESP32_MAJOR >= 2
    bbb
  #elif ARDUINO_ESP32_MAJOR >= 1
    ccc
  #else
    yyy
  #endif
#endif

the compilation fails with error: 'yyy' was not declared in this scope. In other words, the macro does not seems to be defined as you expect.

The macro ARDUINO_ESP32_MAJOR does not seems to be available in arduino-esp32 core:
https://github.com/search?q=repo%3Aespressif%2Farduino-esp32%20ARDUINO_ESP32_MAJOR%20&type=code

I've installed the esp32 core 3.3.1. Please advise.

@ryanhz
Yeah, the macro is not defined:

  #if !defined(ARDUINO_ESP32_MAJOR)
    it_is_undefined
  #endif

fails with error: 'it_is_undefined' was not declared in this scope.

Are you using a custom framework for compiling your esp32 projects ?

The appropriate way seems to be with the following:

#if defined(ESP32)
  #ifdef ESP_ARDUINO_VERSION
    #if ESP_ARDUINO_VERSION >= ESP_ARDUINO_VERSION_VAL(3, 0, 0)
      // Code specific to ESP32 core 3.x
      q111
    #elif ESP_ARDUINO_VERSION >= ESP_ARDUINO_VERSION_VAL(2, 0, 0)
      // Code specific to ESP32 core 2.x
      q222
    #else
      #error ESP32 arduino version unsupported
    #endif
  #else
    // Fallback for older versions (pre-2.x)
    #error ESP32 arduino version unsupported
  #endif
#endif

which fails as expected with error: 'q111' was not declared in this scope; did you mean 'B111'?.

Reference: arduino-esp32's Compatibility Guide for ESP32 Arduino Core.

@end2endzone Sorry, the macro should be ESP_ARDUINO_VERSION_MAJOR. ChatGPT sometimes gave me wrong code.
I thought this is just a 2 lines fix, the pull request was created before I found it not working in ESP32 Core 3.x. There are other places hardcoded channel 0 like

void tone(int frq) {
  ledcWriteTone(0, frq); // channel, freq
  ledcWrite(0, 255); // channel, volume
}

So eventually, I rewrote the whole file at the help of GPT (this commit in my fork), which is working in Core 3.x as I tested, but I haven't test back on core.x. Do you want to to create another pull request?