PWM_MultiChannel.ino

/****************************************************************************************************************************
  PWM_MultiChannel.ino

  For ESP32, ESP32_S2, ESP32_S3, ESP32_C3 boards with ESP32 core v2.0.0+
  Written by Khoi Hoang

  Built by Khoi Hoang https://github.com/khoih-prog/ESP32_FastPWM
  Licensed under MIT license

  This is pure hardware-based PWM
*****************************************************************************************************************************/
/******************************************************************************************************************************
  // All GPIO pins (but GPIO34-39) can be used to generate PWM
  // For ESP32, number of channels is 16, max 20-bit resolution
  // For ESP32_S2, ESP32_S3, number of channels is 8
  // For ESP32_C3, number of channels is 6
******************************************************************************************************************************/

#define _PWM_LOGLEVEL_       4

#include "ESP32_FastPWM.h"

// Max resolution is 20-bit
// Resolution 65536 (16-bit) for lower frequencies, OK @ 1K
// Resolution  4096 (12-bit) for lower frequencies, OK @ 10K
// Resolution  1024 (10-bit) for higher frequencies, OK @ 50K
// Resolution  256  ( 8-bit)for higher frequencies, OK @ 100K, 200K
// Resolution  128  ( 7-bit) for higher frequencies, OK @ 500K
int PWM_resolution       = 12;

#if ARDUINO_ESP32C3_DEV
uint32_t PWM_Pins[]   = { 8, 9 };
#else
uint32_t PWM_Pins[]   = { 16, 17 };
#endif

uint32_t PWM_chan[]       = {  0,  1 };

#define NUM_OF_PINS       ( sizeof(PWM_Pins) / sizeof(uint32_t) )

float dutyCycle[]  = { 20.0f, 50.0f };

// Must be same frequency for same channel
float frequency = 2000.0f;

//creates pwm instances
ESP32_FAST_PWM* PWM_Instance[NUM_OF_PINS];

char dashLine[] = "=====================================================================================";

void printPWMInfo(ESP32_FAST_PWM* PWM_Instance)
{
  Serial.println(dashLine);
  Serial.print("Actual data: pin = ");
  Serial.print(PWM_Instance->getPin());
  Serial.print(", PWM DC = ");
  Serial.print(PWM_Instance->getActualDutyCycle());
  Serial.print(", PWMPeriod = ");
  Serial.print(PWM_Instance->getPWMPeriod());
  Serial.print(", PWM Freq (Hz) = ");
  Serial.println(PWM_Instance->getActualFreq(), 4);
  Serial.println(dashLine);
}

void setup()
{
  Serial.begin(115200);

  while (!Serial && millis() < 5000);

  delay(500);

  Serial.print(F("\nStarting PWM_MultiChannel on "));
  Serial.println(ARDUINO_BOARD);
  Serial.println(ESP32_FAST_PWM_VERSION);

  for (uint8_t index = 0; index < NUM_OF_PINS; index++)
  {
    PWM_Instance[index] = new ESP32_FAST_PWM(PWM_Pins[index], frequency, dutyCycle[index], PWM_chan[index], PWM_resolution);

    if (PWM_Instance[index])
    {
      PWM_Instance[index]->setPWM();
    }
  }

  Serial.println(dashLine);
  Serial.println("Index\tPin\tPWM_freq\tDutyCycle\tActual Freq");
  Serial.println(dashLine);

  for (uint8_t index = 0; index < NUM_OF_PINS; index++)
  {
    if (PWM_Instance[index])
    {
      Serial.print(index);
      Serial.print("\t");
      Serial.print(PWM_Pins[index]);
      Serial.print("\t");
      Serial.print(frequency);
      Serial.print("\t\t");
      Serial.print(dutyCycle[index]);
      Serial.print("\t\t");
      Serial.println(PWM_Instance[index]->getActualFreq(), 4);
    }
    else
    {
      Serial.println();
    }
  }

  for (uint8_t index = 0; index < NUM_OF_PINS; index++)
  {
    printPWMInfo(PWM_Instance[index]);
  }
}

void loop()
{
  //Long delay has no effect on the operation of hardware-based PWM channels
  delay(1000000);
}