#include <stdio.h>
#include "driver/ledc.h"
#include "esp_err.h"
#include "esp_rom_gpio.h"

// ------------------------------------------------------------------------
// ISSUE: When output_invert is enabled, the output will go low for 12.5 us
// after running ledc_timer_config_t
// -----------------------------------------------------------------------

#define LEDC_FREQUENCY     (1000) // Frequency in Hertz
#define LEDC_MODE          LEDC_LOW_SPEED_MODE
//#define LEDC_MODE          LEDC_HIGH_SPEED_MODE
#define LEDC_TIMER         LEDC_TIMER_0
#define LEDC_OUTPUT_IO     (19) // Define the output GPIO
#define LEDC_CHANNEL       LEDC_CHANNEL_0
#define LEDC_DUTY          (255) // Set duty to 25%

static void example_ledc_init(void) {

  // Prepare and then apply the LEDC PWM timer configuration

  ledc_timer_config_t ledc_timer = {
    .speed_mode       = LEDC_LOW_SPEED_MODE,
    .duty_resolution  = LEDC_TIMER_10_BIT,
    .timer_num        = LEDC_TIMER,
    .freq_hz          = LEDC_FREQUENCY,
    .clk_cfg          = LEDC_AUTO_CLK
  };
  ESP_ERROR_CHECK(ledc_timer_config(&ledc_timer));

  ESP_ERROR_CHECK(ledc_timer_pause(LEDC_MODE, LEDC_TIMER));  // pause

  // Prepare and then apply the LEDC PWM channel configuration
  ledc_channel_config_t ledc_channel = {
    .gpio_num       = LEDC_OUTPUT_IO,
    .speed_mode     = LEDC_MODE,
    .channel        = LEDC_CHANNEL,
    .intr_type      = LEDC_INTR_DISABLE,
    .timer_sel      = LEDC_TIMER,
    .duty           = LEDC_DUTY,
    .hpoint         = 0,   // 0xfffff max
    .flags = {
      .output_invert = 0
    }
  };
  ESP_ERROR_CHECK(ledc_channel_config(&ledc_channel));

  // Set duty to 25% and update
  ESP_ERROR_CHECK(ledc_set_duty(LEDC_MODE, LEDC_CHANNEL, LEDC_DUTY));
  ESP_ERROR_CHECK(ledc_update_duty(LEDC_MODE, LEDC_CHANNEL));
}

void setup() {
  Serial.begin(115200);
  //Serial.println(0x3FF44530 + 19 * 4, HEX);
  pinMode(LEDC_OUTPUT_IO, INPUT_PULLUP);
  delay(100);


  example_ledc_init();

  //LEDC_HS_SIG_OUT0_IDX
  //void esp_rom_gpio_connect_out_signal(uint32_t gpio_num, uint32_t signal_idx, bool out_inv, bool oen_inv);
  //esp_rom_gpio_connect_out_signal(LEDC_OUTPUT_IO, LEDC_HS_SIG_OUT0_IDX, true, false);

  //WRITE_PERI_REG(GPIO_FUNCnn_OUT_SEL_CFG_REG, READ_PERI_REG(GPIO_FUNCnn_OUT_SEL_CFG_REG) | GPIO_FUNCnn_OUT_INV_SEL);
  // nn=gpio number

  uint8_t pin = 19;

  REG_WRITE(0x3FF44530 + pin * 4, READ_PERI_REG(0x3FF44530 + pin * 4) | GPIO_FUNC0_OUT_INV_SEL);
  //REG_WRITE(0x3FF44530 + pin * 4, READ_PERI_REG(0x3FF44530 + pin * 4) & ~GPIO_FUNC0_OUT_INV_SEL);

  //REG_WRITE(GPIO_FUNC19_OUT_SEL_CFG_REG, READ_PERI_REG(GPIO_FUNC19_OUT_SEL_CFG_REG) | GPIO_FUNC19_OUT_INV_SEL);
  //WRITE_PERI_REG(GPIO_FUNC19_OUT_SEL_CFG_REG, READ_PERI_REG(GPIO_FUNC19_OUT_SEL_CFG_REG) | GPIO_FUNC19_OUT_INV_SEL);
  //WRITE_PERI_REG(I2S_TIMING_REG(0), 0);


  ESP_ERROR_CHECK(ledc_timer_resume(LEDC_MODE, LEDC_TIMER));  // resume
}

void loop() {
}