Rotary_Encoder

Rotary_Encoder.js

#define SERIAL_BAUDRATE 9600
#define CLK_PIN 2
#define DT_PIN 3
#define SW_PIN 4

#define interruptA 0 // nano腳位2是interrupt 0，其他板子請見官方網頁

int count = 0;
int lastCLK = 0;     //lastCLK 為旋轉編碼器 CLK 預設狀態 =0

void setup() {
  Serial.begin(SERIAL_BAUDRATE);
  // 當狀態下降時，代表旋轉編碼器被轉動了
  attachInterrupt(interruptA, rotaryEncoderChanged, FALLING);
  pinMode(CLK_PIN, INPUT_PULLUP); // 輸入模式並啟用內建上拉電阻
  pinMode(DT_PIN, INPUT_PULLUP);
  pinMode(SW_PIN, INPUT_PULLUP);
}
void loop() {
  if(digitalRead(SW_PIN) == LOW){ // 按下開關，歸零
     count = 0; 
     Serial.println("count reset to 0");
     delay(300);
  }
}
void rotaryEncoderChanged(){ // when CLK_PIN is FALLING
  int clkValue = digitalRead(CLK_PIN);
  int dtValue = digitalRead(DT_PIN);
  if (lastCLK != clkValue)
  {
    lastCLK = clkValue;
    count += (clkValue != dtValue ? 1 : -1);  //旋轉編碼器順時針旋轉時，count +1；逆時針旋轉時， count -1

    Serial.print("count:");
    Serial.println(count);
  }   
}

/*
參考資料:
1.葉難 https://yehnan.blogspot.com/2014/02/arduino.html
2.Ray https://sites.google.com/view/rayarduino/rotary-encoder
3.CH.Tseng https://chtseng.wordpress.com/2015/12/25/
*/

arduino nano 與 旋轉編碼器 的基本程式碼，能用serial monitor監測狀態變化