Freq_Count_2.ino

// Consegui bom resultado deste aqui até 20MHz
unsigned long overun = 20000;
#include "driver/rmt.h"           // RMT library
#include "driver/pcnt.h"          // Pulse count library
#include <WiFi.h>

#define PCNT_TEST_UNIT      PCNT_UNIT_0                 // Unidade de pcnt
#define PCNT_INPUT_SIG_IO   23                          // Pulse Input GPIO
#define PCNT_INPUT_CTRL_IO  25                          // Control GPIO HIGH=count up, LOW=count down
#define LEDC_IO  18                          // Control GPIO HIGH=count up, LOW=count down

#define PCNT_H_LIM_VAL      overun                       // Limite superior de contagem

bool flag = false;
int16_t pulses = 0;

long  frequencia = 1;                 // frequencia em Hz
long  canal = 1;                      // canal gerador de sinal
long  resolBits = 16;                 // bits de resolucao
long dutyCycle = 32770;               // valor divisor de Duty Cycle

unsigned long multPulses = 0;

//----------------------------------------------------------------------------
void freqAdjust ()
{
  pinMode(LEDC_IO, OUTPUT);                          // GPIO_18 as Output
  ledcAttachPin(LEDC_IO, canal);                     // GPIO_18 attached to PWM Channel
  ledcSetup(canal, frequencia, resolBits);      // Channel  , freq  ,  bit resolution
  ledcWrite(canal, dutyCycle);                  // Enable frequency with dutty cycle
}
//----------------------------------------------------------------------------------
static void IRAM_ATTR pcnt_example_intr_handler(void *arg)
{
  uint32_t intr_status = PCNT.int_st.val;
  int i;
  for (i = 0; i < PCNT_UNIT_MAX; i++)
  {
    if (intr_status & (BIT(i)))
    {
      multPulses++;
      PCNT.int_clr.val = BIT(i);
    }
  }
}
//----------------------------------------------------------------------------------
void IRAM_ATTR detectsCount()
{
  pulses = REG_READ(PCNT_U0_CNT_REG);
  pcnt_counter_clear(PCNT_TEST_UNIT);                     // Zera o contador PCNT
  flag = false;
}
//----------------------------------------------------------------------------------
void setup()
{
  WiFi.mode( WIFI_MODE_NULL );
  btStop();
  Serial.begin(115200);                                   // Inicializa a serial
  pcnt_init();                                            // Inicializa o pulse count
  attachInterrupt(digitalPinToInterrupt(25), detectsCount, FALLING);
  freqAdjust();
}
//---------------------------------------------------------------------------------
void loop()
{
  if (flag == false)
  {
    float calculo = 0;
    float resFinal = 0;
    calculo = (pulses + (multPulses * overun))  ;
    resFinal = 0.00000585 * calculo +   calculo;
    Serial.print("  Total: ");  Serial.println ((resFinal), 0 );     // Print
    multPulses = 0;
    flag = true;
  }
}
//----------------------------------------------------------------------------------
void pcnt_init(void)                                      // Rotina de inicializacao do pulse count
{
  pcnt_config_t pcnt_config = { };                        // Instancia pulse config
  pcnt_config.pulse_gpio_num = PCNT_INPUT_SIG_IO;         // Port de entrada dos pulsos
  pcnt_config.ctrl_gpio_num = PCNT_INPUT_CTRL_IO;         // Controle da contagem
  pcnt_config.counter_h_lim = PCNT_H_LIM_VAL;             // Limite maximo de contagem
  pcnt_config.pos_mode = PCNT_COUNT_INC;                  // Conta na subida do pulso
  pcnt_config.neg_mode = PCNT_COUNT_INC;                  // Conta na descida do pulso
  pcnt_config.lctrl_mode = PCNT_MODE_DISABLE;             // Nao usado
  pcnt_config.hctrl_mode = PCNT_MODE_KEEP;                // Se HIGH conta incrementando
  pcnt_unit_config(&pcnt_config);                         // Inicializa PCNT

  pcnt_counter_pause(PCNT_TEST_UNIT);                     // Inicializa o contador PCNT
  pcnt_counter_clear(PCNT_TEST_UNIT);                     // Zera o contador PCNT
  pcnt_counter_resume(PCNT_TEST_UNIT);                    // inicia a contagem

  pcnt_event_enable(PCNT_TEST_UNIT, PCNT_EVT_H_LIM);
  pcnt_isr_register(pcnt_example_intr_handler, NULL, 0, NULL);
  pcnt_intr_enable(PCNT_TEST_UNIT);
}