레슨 97-3: 로터리 엔코더를 사용하여 서보 모터 제어 및 LCD에 각도 표시

/*
 * Lesson 97-3: Controlling Servo Motor using Rotary Encoder and Display Angle on LCD
 Download and resource page https://robojax.com/RJT453

 *  Watch full details video: https://youtu.be/6xVLbNlmK-g
  This video is part of Arduino Step by Step Course which starts here: https://youtu.be/-6qSrDUA5a8
 

If you found this tutorial helpful, please support me so I can continue creating 
content like this. Make a donation using PayPal by credit card https://bit.ly/donate-robojax
  
 * This code is "AS IS" without warranty or liability. Free to be used as long as you keep this note intact.* 
 * This code has been downloaded from Robojax.com
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <https://www.gnu.org/licenses/>.
 *  Updated by Ahmad Shamshiri on Jan 23, 2022
 *  Encoder Library - Basic Example
 * http://www.pjrc.com/teensy/td_libs_Encoder.html
 *
 * This example code is in the public domain.
 */
const int SW_PIN = 4;//define a pin for rotary encode switch
const int PIN_A =2;
const int PIN_B =3;

#include <Encoder.h>

// Change these two numbers to the pins connected to your encoder.
//   Best Performance: both pins have interrupt capability
//   Good Performance: only the first pin has interrupt capability
//   Low Performance:  neither pin has interrupt capability
Encoder myEnc(PIN_A, PIN_B);
//   avoid using pins with LEDs attached

const int homePosition = 90; //initial position
const int stepValue = 3;//how fast the servo should rotate when turning the knob
const int servoPin = 9;//~must be a pin that that is labeled with ~
#include <Servo.h>

Servo myservo;  // create servo object to control a servo
int servoAngel =homePosition;


#include <Wire.h>
#include <LiquidCrystal_I2C.h>
// Set the LCD address to 0x27 or 0x3F for a 16 chars and 2 line display
LiquidCrystal_I2C lcd(0x3F, 16, 2);

void setup() {
  Serial.begin(9600);
  pinMode(SW_PIN, INPUT);
  Serial.println("Robojax Encoder with LCD and Servo");
   myservo.attach(servoPin);  // attaches the servo on pin
   myservo.write(servoAngel);//move servo to initial position

  lcd.begin();
  // Turn on the blacklight and print a message.
  lcd.backlight();     
  lcd.print("Robojax Encoder");
  lcd.setCursor (0,1); // go to start of 2nd line
  lcd.print("Servo Test");   
  delay(2000);   
   lcd.clear();// clear previous values from screen   
  lcd.print("Robojax Encoder");
  lcd.setCursor (0,1); // go to start of 2nd line  
  lcd.print("Angle: ");   
}

long oldPosition  = -999;

void loop() {
  long newPosition = myEnc.read();
  if (newPosition != oldPosition) {

    if(newPosition >  oldPosition)
    {
    int newStep = abs(newPosition - oldPosition);
      Serial.print("Angle ");
      Serial.println(servoAngel);      
      servoAngel -= stepValue;
      if(servoAngel <0)
          servoAngel =0;      
      myservo.write(servoAngel); //move servo to new angle
      lcdAngel(servoAngel);//print on LCD
    }

    if(newPosition <  oldPosition )
    {
    int newStep = abs(newPosition - oldPosition);
      Serial.print("Angle ");
      Serial.println(servoAngel);        
      servoAngel += stepValue;
      if(servoAngel >180)
          servoAngel =180;
      myservo.write(servoAngel); //move servo to new angle
      lcdAngel(servoAngel);//print on LCD
    }
   oldPosition = newPosition;//remember the new position
  }

  if( digitalRead(SW_PIN) == LOW)
  {
    Serial.print("Home: ");
    Serial.println(homePosition);
    servoAngel =homePosition;
      myservo.write(servoAngel); //move servo to new angle
      lcdAngel(servoAngel);//print on LCD
  
  }

  //delay(200);
}

/*
 * lcdAngel(int angel)
 * prints the angle on LCD
 * written by Ahmad Shamshiri
 * www.robojax.com
 * Jan 27, 2022 at 13:18
 * Watch full details video: https://youtu.be/6xVLbNlmK-g
 */
void lcdAngel(int angel)
{
  
  int startChar =7;
  for(int i=startChar; i<16; i++)
  {
   lcd.setCursor (i,1);    
    lcd.print(" ");   
  }
 
   lcd.setCursor (startChar,1); // line 1 
   lcd.print(angel); 
   lcd.print((char)223);
}