#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_log.h"
#include "esp_adc/adc_oneshot.h"
#include "driver/ledc.h"

#define CONFIG_LOG_MAXIMUM_LEVEL  5

static const char *TAG = "ADC_PWM";

// 硬體配置
#define ADC_CHAN          ADC_CHANNEL_6 // GPIO 7
#define LED_PIN           GPIO_NUM_41   // GPIO 41

 // LEDC (PWM) 配置
#define LEDC_TIMER       LEDC_TIMER_0
#define LEDC_MODE        LEDC_LOW_SPEED_MODE
#define LEDC_CHANNEL     LEDC_CHANNEL_0
#define LEDC_DUTY_RES    LEDC_TIMER_12_BIT // 12位元解析度(0-4095)
#define LEDC_FREQUENCY   5000              // 5kHz

void ledc_init() {
    // 設置時脈
    ledc_timer_config_t ledc_timer = {
        .speed_mode       = LEDC_MODE,
        .timer_num        = LEDC_TIMER,
        .duty_resolution  = LEDC_DUTY_RES,
        .freq_hz          = LEDC_FREQUENCY,
        .clk_cfg          = LEDC_AUTO_CLK
    };
    ledc_timer_config(&ledc_timer);

    // 設置輸出通道
    ledc_channel_config_t ledc_channel = {
        .speed_mode     = LEDC_MODE,
        .channel        = LEDC_CHANNEL,
        .timer_sel      = LEDC_TIMER,
        // .intr_type      = LEDC_INTR_DISABLE,
        .gpio_num       = LED_PIN,
        .duty           = 0,
        .hpoint         = 0
    };
    ledc_channel_config(&ledc_channel);
}

// ADC 讀取任務
void adc_pwm_task(void *arg) {
    // 初始化ADC、建立ADC控制物件
    adc_oneshot_unit_handle_t adc_handle;
    adc_oneshot_unit_init_cfg_t init_cfg = { .unit_id = ADC_UNIT_1 };
    ESP_ERROR_CHECK(adc_oneshot_new_unit(&init_cfg, &adc_handle));

    adc_oneshot_chan_cfg_t chan_cfg = {
        .bitwidth = ADC_BITWIDTH_DEFAULT,
        .atten    = ADC_ATTEN_DB_12,
    };
    ESP_ERROR_CHECK(adc_oneshot_config_channel(adc_handle, ADC_CHAN, &chan_cfg));

    int raw_val = 0;
    int last_val = -1;

    while (1) {
        if (adc_oneshot_read(adc_handle, ADC_CHAN, &raw_val) == ESP_OK) {
          // 避免頻繁更新輸出
          if(abs(raw_val - last_val) >= 10) {
            // 直接將12位元ADC值設給12位元PWM
            ledc_set_duty(LEDC_MODE, LEDC_CHANNEL, raw_val);
            ledc_update_duty(LEDC_MODE, LEDC_CHANNEL);
            
            ESP_LOGI(TAG, "ADC值：%d", raw_val);
            last_val = raw_val;
          }
        }
        vTaskDelay(pdMS_TO_TICKS(20)); // 短暫延遲
    }
}


void app_main(void) {
    esp_log_level_set(TAG, ESP_LOG_VERBOSE);
    ledc_init();   // 初始化 PWM

    // 啟動任務
    xTaskCreate(adc_pwm_task, "adc_to_pwm", 3000, NULL, 4, NULL);
}