Arduino Servo Example - Using Potentiometer To Vary Servo or Pushbutton To Set To Fixed Position

servo_with_3_buttons_and_pot.ino

/**************************************************
Udemy Arduino Step-by-Step Course
Section 5 Motors Lecture 51 Servo Motors Part 2
Quiz Servo With 3 Buttons (not graded, not for credit, fun only:-)
by J. Cantlin 
June 17, 2016
***************************************************/

/**************************************************
Description of Program
A small servo motor is setup to be contolled by a 
10k potentiomer. Moving the pot with move the servo
throughtout its range of motion (approximately 170 degrees).

The servo will also be set to fix positions of 60, 90 and 180
degrees when pushbuttons 1, 2, or 3 are pressed respectively.

A 1000uF capacitor is placed across the +5vdc to Ground
to protect the Arduino from the high starting current
when the servo power is first applied.
***************************************************/

/**************************************************
Summary of Arduino Uno Analog Pins Used:
A0 = 10k potentiometer (wiper arm = center pin)
A1 = 
A2 = 
A3 = 
A4 = 
A5 = 
***************************************************/

/**************************************************
Summary of Arduino Uno Digital Pins Used:
00 =               //Avoid RX pin - used for serial port
01 =               //Avoid TX pin - used for serial port
02 = button 2 (between 10k resistor and ground)
03 = button 2 (between 10k resistor and ground)
04 = button 3 (between 10k resistor and ground)
05 = 
06 = 
07 = 
08 = 
09 = servo control signal (orange wire for this servo)
10 = 
11 = 
***************************************************/

/**********************************************************************
VarSpeedServo.h Arduino Library:

The VarSpeedServo.h Arduino library allows the use of up to 8 servos moving
asynchronously (because it uses interrupts) to a position specified in the
write(position) function. In addition, you can optionally set the speed of
a move (0 to 255), or set a wait flag "true" to have the program wait until
the servo move is complete before proceeding. You can  create sequences
of moves that run asynchronously. Format: write(pos,speed,true)

This code is an adaptation of the standard Arduino Servo.h library.

Reference:
https://github.com/netlabtoolkit/VarSpeedServo
***********************************************************************/
#include <VarSpeedServo.h> 
 
VarSpeedServo myservo;    //create a new servo object to control a servo 

// Analog Pin Assignments
const int potPin = 0;     //analog pin used to connect the potentiometer

// Digital Pin Assignments
const int servoPin = 9;   // the digital pin used for the servo
const int button1Pin = 2; // the digital pin used for the button 1
const int button2Pin = 3; // the digital pin used for the button 2
const int button3Pin = 4; // the digital pin used for the button 3

// Initialize Global Variables
int valPot;               // variable to read the value from the analog pin
int button1State = 0;     // button status variable, initial state = 0 = not pressed
int button2State = 0;     // button status variable, initial state = 0 = not pressed
int button3State = 0;     // button status variable, initial state = 0 = not pressed

void setup()
{//****start setup function****
  //Serial.begin(9600);      //set the serial port to 9600 baud if monitor is used
  myservo.attach(servoPin);  //attaches the new servo object to the assigned digital pin
 
  // initialize the pushbutton pins as inputs
  pinMode(button1Pin, INPUT);
  pinMode(button2Pin, INPUT);
  pinMode(button3Pin, INPUT);
   
}//****endof setup function****

void loop()
{//****start infinite loop****
  valPot = analogRead(potPin);            //read the potentiometer analog value
  delay(10);                              // short delay to allow readings to stabilize
  valPot = map(valPot, 0, 1023, 0, 180);  // scale potVal to servo (0 to 180 degrees) 
  myservo.write(valPot);                  // sets servo position according to the scaled value 

  // read the state of the pushbuttons - HIGH = pushed
  button1State = digitalRead(button1Pin);
  button2State = digitalRead(button2Pin);
  button3State = digitalRead(button3Pin);
   
    if(button1State == HIGH)
      {//****start button1 pressed loop****
      myservo.write(60); //move to 60% at full speed, wait until at 60%
      }//****endof button1 pressed loop****

   if(button2State == HIGH)
      {//****start button2 pressed loop****
       myservo.write(90); //move to 90% at full speed, wait until at 90%
      }//****endof button2 pressed loop****

   if(button3State == HIGH)
      {//****start button3 pressed loop****
       myservo.write(180); //move to 180% at full speed, wait until at 180%
      }//****endof button3 pressed loop****

 /********************************************************************/
//  Print data used for testing and debugging - comment out as needed.
//  Warning: using the serial port may conflict with servo commands.
//  Serial.print("Potentiometer Reading: ");
//  Serial.println(valPot, DEC); // print the potentiometer reading, ln for new line
//  Serial.print("Button 1 Reading: ");
//  Serial.println(button1State); // print the potentiometer reading, ln for new line
//  Serial.print("Button 2 Reading: ");
//  Serial.println(button2State); // print the potentiometer reading, ln for new line
//  Serial.print("Button 3 Reading: ");
//  Serial.println(button3State); // print the potentiometer reading, ln for new line
//  delay(100);  // waitfor next reading
/********************************************************************/

}//****endof infinite loop****