Arduino_quadrature_encoder

quadrature_encoder.ino

//ロータリーエンコーダを試す
// 2016/06/04 edy
//
//How to use a quadrature encoder
//http://www.robotshop.com/media/files/PDF/tutorial-how-to-use-a-quadrature-encoder-rs011a.pdf

#include <LiquidCrystal.h>

// 接続ピンをして指定してライブラリを初期化
//LiquidCrystal(rs, enable, d4, d5, d6, d7)
LiquidCrystal lcd(7, 6, 8, 9, 10, 11);

int new_SW, old_SW;
volatile int count = 0;
volatile int intcount = 0; //割り込み回数

const int QEM[] = {0, -1, 1, 2, 1, 0, 2, -1, -1, 2, 0, 1, 2, 1, -1, 0};
//const int QEM[] = {0, -1, 1, 0, 1, 0, 0, -1, -1, 0, 0, 1, 0, 1, -1, 0};

void setup()
{
  lcd.begin(16, 2);
  pinMode(4, INPUT);
  pinMode(5, INPUT);
  attachInterrupt(1, QE_IRQ, CHANGE);
  new_SW = digitalRead (4) * 2 + digitalRead (5);
}

void loop()
{
  lcd.setCursor(0, 0);
  lcd.print(count, DEC);
  lcd.print("      ");
  lcd.setCursor(8, 0);
  lcd.print(count / 4, DEC);
  lcd.print("      ");

  lcd.setCursor(0, 1);
  lcd.print(intcount, DEC);
  lcd.print("      ");
  delay(100);
}


void QE_IRQ(void)
{
  int out ;
  old_SW = new_SW;
  new_SW = digitalRead (4) * 2 + digitalRead (5);
  out = QEM[old_SW * 4 + new_SW];;
  count += out;
  intcount++;
}