ESP32_LEDc.ino

/ Oscilador inicial, criado pelo GUSTAVO

// ESP32 DEVKIT / Arduino IDE 1.8.9.  / ESP32 versao 1.0.4
// Based on  https://portal.vidadesilicio.com.br/controle-de-potencia-via-pwm-esp32/
//           https://randomnerdtutorials.com/esp32-pwm-arduino-ide/
//           https://techtutorialsx.com/2017/06/15/esp32-arduino-led-pwm-fading/
// Max Freq = 40 MHz / bit resolution   (Bit resolution = 1 to 16 bit)
// Duty cycle = decimal * 100 / (2 ^ bit resolution)
// Reference  https://github.com/espressif/arduino-esp32/blob/master/cores/esp32/esp32-hal-ledc.c
//            https://docs.espressif.com/projects/esp-idf/en/latest/api-reference/peripherals/ledc.html
// Exemplo: para um duty cycle de 50% com 10bits (2^10 = 1024) de resolução, devemos escrever 512.

//  resolBits = log((80000000 / frequencia)) + 1;
//  dutyCycle = (pow(2, resolBits)) / 2;

//-------------------------------------------------------------------
void setup()
{
  Serial.begin(115200);
  pinMode(18, OUTPUT);             // GPIO_18 as Output
  ledcAttachPin(18, 1);            // GPIO_18 attached to PWM Channel 1
  ledcSetup(1, 250000, 5);         // Channel 1 , freq 250 KHz , 5 bit resolution = 32
  ledcWrite(1, 8);                 // Enable frequency with dutty cycle 25%
}
//-------------------------------------------------------------------
void loop()
{
  ;
}