#include "stdio.h"                                                        // Library STDIO
#include "driver/ledc.h"                                                  // Library ESP32 LEDC
#include "driver/pcnt.h"                                                  // Library ESP32 PCNT
#include "soc/pcnt_struct.h"



void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32-C3!");
  uint32_t f = getCpuFrequencyMhz();
  Serial.println(f);
  init_osc_freq();
}

void loop() {
  
}


void init_osc_freq ()                                                     // Initialize Oscillator to test Freq Meter
{
  ledc_timer_config_t ledc_timer = {};                                    // LEDC timer config instance

  ledc_timer.duty_resolution =  ledc_timer_bit_t(1);                      // Set resolution
  ledc_timer.freq_hz    = 40000000;                                       // Set Oscillator frequency
  ledc_timer.speed_mode = LEDC_LOW_SPEED_MODE;                            // Set low speed mode ESP32C3
  ledc_timer.timer_num = LEDC_TIMER_0;                                    // Set LEDC timer index - 0
  ledc_timer_config(&ledc_timer);                                         // Set LEDC Timer config

  ledc_channel_config_t ledc_channel = {};                                // LEDC Channel config instance

  ledc_channel.channel    = LEDC_CHANNEL_0;                               // Set HS Channel - 0
  ledc_channel.duty       = 1;                                            // Set Duty Cycle 50%
  ledc_channel.gpio_num   = 2;                                            // LEDC Oscillator output GPIO 33
  ledc_channel.intr_type  = LEDC_INTR_DISABLE;                            // LEDC Fade interrupt disable
  ledc_channel.speed_mode = LEDC_LOW_SPEED_MODE;                          // Set LEDC high speed mode
  ledc_channel.timer_sel  = LEDC_TIMER_0;                                 // Set timer source of channel - 0
  ledc_channel_config(&ledc_channel);                                     // Config LEDC channel
}

portMUX_TYPE timerMux = portMUX_INITIALIZER_UNLOCKED;  
uint32_t        multPulses    = 0;     

//----------------------------------------------------------------------------------
static void IRAM_ATTR pcnt_intrrupt_handler(void *arg)                        // Counting overflow pulses
{
  portENTER_CRITICAL_ISR(&timerMux);                                      // disabling the interrupts
  multPulses++;                                                           // increment Overflow counter
  PCNT.int_clr.val = BIT(PCNT_UNIT_0);                                    // Clear Pulse Counter interrupt bit
  portEXIT_CRITICAL_ISR(&timerMux);                                       // enabling the interrupts
}

//----------------------------------------------------------------------------------
void init_PCNT(void)                                                      // Initialize and run PCNT unit
{
  pcnt_config_t pcnt_config = { };                                        // PCNT unit instance

  pcnt_config.pulse_gpio_num = 3;                                         // Pulse input GPIO 3 - Freq Meter Input
  pcnt_config.ctrl_gpio_num = 0;                                          // Control signal input GPIO 3
  pcnt_config.unit = PCNT_UNIT_0;                                         // Unidade de contagem PCNT - 0
  pcnt_config.channel = PCNT_CHANNEL_0;                                   // PCNT unit number - 0
  pcnt_config.counter_h_lim = 20000;                                      // Maximum counter value - 20000
  pcnt_config.pos_mode = PCNT_COUNT_INC;                                  // PCNT positive edge count mode - inc
  pcnt_config.neg_mode = PCNT_COUNT_INC;                                  // PCNT negative edge count mode - inc
  pcnt_config.lctrl_mode = PCNT_MODE_DISABLE;                             // PCNT low control mode - disable
  pcnt_config.hctrl_mode = PCNT_MODE_KEEP;                                // PCNT high control mode - won't change counter mode
  pcnt_unit_config(&pcnt_config);                                         // Initialize PCNT unit

  pcnt_counter_pause(PCNT_UNIT_0);                                        // Pause PCNT unit
  pcnt_counter_clear(PCNT_UNIT_0);                                        // Clear PCNT unit

  pcnt_event_enable(PCNT_UNIT_0, PCNT_EVT_H_LIM);                         // Enable event to watch - max count
  pcnt_intrrupt_handler(pcnt_intr_handler, NULL, 0, NULL);                    // Setup Register ISR handler
  pcnt_intr_enable(PCNT_UNIT_0);                                          // Enable interrupts for PCNT unit

  pcnt_counter_resume(PCNT_UNIT_0);                                       // Resume PCNT unit - starts count
}