#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_adc/adc_oneshot.h"
#include <math.h>

#define NUM_SAMPLES 128

float ntc_to_temperature(int adc_raw)
{
  const float B = 3950.0;
  const float R0 = 10000.0;
  const float T0 = 298.15;

  float k = (float)adc_raw / 4095.0;
  float voltage = k * 3.3;
  float r_ntc = R0 * voltage / (3.3 - voltage);
  float inverse_temperature = 1.0 / T0 + log(r_ntc / R0) / B;

  float temperature = 1.0 / inverse_temperature;

  return temperature - 273.15;
}

void app_main(void)
{
  printf("Hello, Wokwi!\n");

  adc_oneshot_unit_handle_t adc1_handle;

  adc_oneshot_unit_init_cfg_t init_config1 = {
    .unit_id = ADC_UNIT_1,
    .ulp_mode = ADC_ULP_MODE_DISABLE,
  };

  ESP_ERROR_CHECK(
    adc_oneshot_new_unit(&init_config1, &adc1_handle)
  );

  adc_oneshot_chan_cfg_t config = {
    .bitwidth = ADC_BITWIDTH_DEFAULT,
    .atten = ADC_ATTEN_DB_12,
  };

  ESP_ERROR_CHECK(
    adc_oneshot_config_channel(
      adc1_handle,
      ADC_CHANNEL_3,
      &config
    )
  );

  while (true) {

    int adc_raw;
    long sum = 0;

    for (int i = 0; i < NUM_SAMPLES; i++) {
      ESP_ERROR_CHECK(
        adc_oneshot_read(
          adc1_handle,
          ADC_CHANNEL_3,
          &adc_raw
        )
      );
      sum += adc_raw;
    }

    int adc_avg = sum / NUM_SAMPLES;
    float temp = ntc_to_temperature(adc_avg);
    printf("ADC avg: %d | Temperature: %.2f C\n", adc_avg, temp);



    vTaskDelay(pdMS_TO_TICKS(100));
  }
}