Lesson 2

Read Button

In this lesson, you’ll learn how to write a program that gets input from a button!

Write Code (Java)

Copy the code below into the project you created. If you don't have a project or forgot how to create one, revisit the Configure section.

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package gettingstarted;

//Add Phidgets Library 
import com.phidget22.*;

public class GettingStarted {
    //Handle Exceptions 
    public static void main(String[] args) throws Exception{
        
        //Create 
        DigitalInput redButton = new DigitalInput();

        //Address 
        redButton.setHubPort(0);
        redButton.setIsHubPortDevice(true);

        //Open 
        redButton.open(1000);

        //Use your Phidgets 
        while(true){
            System.out.println("Button State: " + redButton.getState());
            Thread.sleep(150);
        }
    }
}

  
//Add Phidgets Library 
import com.phidget22.*;

public class GettingStarted {
    //Handle Exceptions 
    public static void main(String[] args) throws Exception{
        
        //Create 
        DigitalInput redButton = new DigitalInput();

        //Address 
        redButton.setHubPort(0);
        redButton.setIsHubPortDevice(true);

        //Open 
        redButton.open(1000);

        //Use your Phidgets 
        while(true){
            System.out.println("Button State: " + redButton.getState());
            Thread.sleep(150);
        }
    }
}

  
//Add Phidgets Library 
import com.phidget22.*;

//Define
DigitalInput redButton;

void setup(){
  try{
    
    //Create 
     redButton = new DigitalInput();
    
    //Address 
    redButton.setHubPort(0);
    redButton.setIsHubPortDevice(true);
    
    //Open 
    redButton.open(1000);
    
  }catch(Exception e){
    //Handle Exceptions 
    e.printStackTrace();
  }
}

void draw(){
  try{
    //Use your Phidgets 
    println(redButton.getState());
    delay(150);
    
  }catch(Exception e){
    //Handle Exceptions 
    e.printStackTrace();
  }
}

Write Code (Python)

Copy the code below into the project you created. If you don't have a project or forgot how to create one, revisit the Configure section.

Not your programming language? Set your preferences so we can display relevant code examples

  
#Add Phidgets Library 
from Phidget22.Phidget import *
from Phidget22.Devices.DigitalInput import *
#Required for sleep statement
import time 
 
#Create 
redButton = DigitalInput()

#Address 
redButton.setHubPort(0)
redButton.setIsHubPortDevice(True)

#Open 
redButton.openWaitForAttachment(1000)
        
#Use your Phidgets 
while (True):
    print("Button State: " + str(redButton.getState()));
    time.sleep(0.15)

Write Code (C#)

Copy the code below into the project you created. If you don't have a project or forgot how to create one, revisit the Configure section.

Not your programming language? Set your preferences so we can display relevant code examples

  
//Add Phidgets Library 
using Phidget22;

namespace GettingStarted{
    class Program{
        static void Main(string[] args){

            //Create 
            DigitalInput redButton = new DigitalInput();

            //Address 
            redButton.HubPort = 0;
            redButton.IsHubPortDevice = true;

            //Open 
            redButton.Open(1000);

            //Use your Phidgets 
            while (true){
                System.Console.WriteLine("Button State: " + redButton.State);
                System.Threading.Thread.Sleep(150);
            }
        }
    }
}

Write Code (Swift)

Create a label in your window and copy the code below into the project you created. If you don't have a project or forgot how to create one, revisit the Configure section.

Not your programming language? Set your preferences so we can display relevant code examples

Create a label

  
import Cocoa
//Add Phidgets Library 
import Phidget22Swift

class ViewController: NSViewController {
    
    @IBOutlet weak var buttonLabel: NSTextField!
    
    //Create 
    let redButton = DigitalInput()
    
    override func viewDidLoad() {
        super.viewDidLoad()
        do{
            //Address 
            try redButton.setHubPort(0)
            try redButton.setIsHubPortDevice(true)
            
            //Subscribe to event
            let _ = redButton.stateChange.addHandler(state_change)
            
            //Open 
            try redButton.open()
            
        }catch{
            print(error)
        }
    }
    
    func state_change(sender:DigitalInput, state: Bool){
        DispatchQueue.main.async {
            //Use your Phidget 
            self.buttonLabel.stringValue = String(state)
        }
    }
}

Run Your Program

When you press the red button, you will see the button state change.

Practice

Modify the loop to repeat every 10ms, 1000ms, 5000ms. Note how the behavior of your program changes with the different times.
Modify your code to print the state of your green button (Hint: Address).
Modify your code to only print when the button state changes.

Practice

Modify the loop to repeat every 10ms, 1000ms, 5000ms. Note how the behavior of your program changes with the different times.
Modify your code to print the state of your green button (Hint: Address).
Modify your code to only print when the button state changes.

Practice

Modify the loop to repeat every 10ms, 1000ms, 5000ms. Note how the behavior of your program changes with the different times.
Modify your code to print the state of your green button (Hint: Address).
Modify your code to only print when the button state changes.

Practice

Modify your program to change the label to “Pressed” and “Released” instead of true and false.
Modify your code to print the state of your green button (Hint: Address).

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Troubleshoot

I am getting a "Timed Out" exception.

Make sure the USB cable from your VINT Hub to your computer is attached properly.
Make sure you are connected to the correct port on your VINT Hub. In this case your red button should be connected to port 0.
Make sure no other program is running that uses Phidgets. If a Phidget is already in use in another program, it will be busy and won't respond to this one.

The button is not working properly.

Check the button assembly. If the switch and button are not assembled correctly your program will not work properly. The plastic plunger should align with the activator as shown below.

Still having issues?

Visit the Advanced Troubleshooting Page or contact us (education@phidgets.com).

Back to Lesson 1 Next: Lesson 3

Read Button

Write Code (Java)

Write Code (Python)

Write Code (C#)

Write Code (Swift)

Run Your Program

Practice

Practice

Practice

Practice

Troubleshoot

What are Phidgets?

Getting Started

Device Tutorials

Projects

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