# LAB2 可變電阻調整LED
## DEMO
<iframe width="560" height="315" src="https://www.youtube.com/embed/FpCYZQQDTxw?si=g6TqX5cqcoVbMrZt" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>

## 電路圖
- 不要接12!
- 不要接12!
- 不要接12!
- 不要接12!
- 這是血的教訓

## 程式碼說明
- 讀取可變電阻數值，並映射到0~255

    // 讀取紅色輸入數值
    int red_val = analogRead(potpinr);
    red_val = map(red_val, 0, 4095, 0, 255);

    // 讀取綠色輸入數值
    int green_val = analogRead(potping);
    green_val = map(green_val, 0, 4095, 0, 255);

    // 讀取藍色輸入數值
    int blue_val = analogRead(potpinb);
    blue_val = map(blue_val, 0, 4095, 0, 255);

- LED燈輸出

    color(red_val, green_val, blue_val);

- `color`函數

        void color (unsigned char red, unsigned char green, unsigned char blue) {
          analogWrite(redPin, red);
          analogWrite(greenPin, green);
          analogWrite(bluePin, blue);
        }

- LCD更新

    lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("(R, G, B)");
    lcd.setCursor(0, 1);
    lcd.print(String(red_val) + ", " + String(green_val) + ", " + String(blue_val));

## 程式碼

/*
  * 電路模組用全彩LED模組、LCD模組
  * ESP32 有匯入analogWrite.h，需去 草稿碼 > 匯入函式庫 > 管理函式庫
  * ESP32 LiquidCrystal_I2C.h，需去 草稿碼 > 匯入函式庫 > 管理函式庫
*/
#include <analogWrite.h>
#include <LiquidCrystal_I2C.h> 


// LED 和可變電阻的腳位
int redPin = 17;
int greenPin = 16;
int bluePin = 15;
int potpinr = 27;
int potping = 14;
int potpinb = 13;

LiquidCrystal_I2C lcd(0x27,16,2);

void setup() {
  // 初始化 Serial
  Serial.begin(9600);
  
  // 設定 LED 腳位為輸出
  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);

  lcd.init();
  lcd.backlight();
}

void loop() {
  // 讀取紅色輸入數值
  int red_val = analogRead(potpinr);
  red_val = map(red_val, 0, 4095, 0, 255);

  // 讀取綠色輸入數值
  int green_val = analogRead(potping);
  green_val = map(green_val, 0, 4095, 0, 255);

  // 讀取藍色輸入數值
  int blue_val = analogRead(potpinb);
  blue_val = map(blue_val, 0, 4095, 0, 255);

  Serial.printf("r: %u g: %u b: %u\n", red_val, green_val, blue_val);

  //更新LCD數值
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("(R, G, B)");
  lcd.setCursor(0, 1);
  lcd.print(String(red_val) + ", " + String(green_val) + ", " + String(blue_val));
  // 更新 LED 顏色
  color(red_val, green_val, blue_val);
  delay(100);
}

// 控制LED顏色
void color (unsigned char red, unsigned char green, unsigned char blue) {
  analogWrite(redPin, red);
  analogWrite(greenPin, green);
  analogWrite(bluePin, blue);
}