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<metadesc>Communicate over USB with sensors, controllers and relays with Phidgets! Our Swift library supports iOS using Xcode.</metadesc>
[[Category:Language]]
== Quick Downloads ==
__NOTOC__


Already know what you're doing? Here you go:
We provide support for the Swift language on macOS. We also provide instructions on how to get your project started in Xcode for use in '''macOS''' and '''iOS''' applications. Select your operating system below, and follow the instructions to get your project running with Phidgets.


=== Documentation ===
Once you have set up your development environment to run with Phidgets, we recommend you follow our guide on [[Phidget Programming Basics]]. The guide will showcase the fundamentals of programming with Phidgets.


*{{Phidget22API}}
==Setup Guide==


=== Example Code ===
<div class="phd-deck-sequence">
  __NOTOC__
{{PT3_SWIFT_CHOOSE}}{{PT3_SWIFT_MAC_XCODE}}{{PT3_SWIFT_MAC_XCODE_1}}{{PT3_SWIFT_MAC_XCODE_2}}{{PT3_SWIFT_IOS_XCODE}}{{PT3_SWIFT_IOS_XCODE_1}}{{PT3_SWIFT_IOS_XCODE_2}}
</div>


*{{SampleCode|Swift|Swift Examples}}


=== Libraries ===
== Quick Downloads ==


{{MacQuickDownloads}}
If you already know what you're doing and just need the files, you can find them all below.
{{iOSQuickDownloads}}


== Getting Started with Swift ==
=== Documentation ===
Welcome to using Phidgets with Swift! By using Swift, you will have access to the complete {{Phidget22API}}, including events. We also provide example code in Swift for multiple Phidget classes.


== iOS ==
*{{Phidget22API}} (select Swift from the drop-down menu)
{{IOS_Languages}}
===Xcode===
====Use Our Examples====
One of the best ways to start programming with Phidgets is to use our example code as a guide. In order to run the examples for iOS you will need to download [https://developer.apple.com/xcode/ Xcode] from the Mac App Store.


=== Example Code ===


Now that you have Xcode installed, download the Swift example:
*{{SampleCode|Swift|Swift Examples}}
*{{SampleCode|Swift|Swift Example}}
 
 
You have previously downloaded the Phidget iOS libraries on the iOS page, but here they are again, just in case:
*[{{SERVER}}/downloads/phidget22/libraries/ios/Phidget22_iOS.zip Phidget iOS Libraries]
 
 
Next, unpack the Swift example and navigate to ''Phidget.xcodeproj''. Open the file in Xcode:
[[Image:Swift_open.png|link=|center]]
 
 
{{IOS_use_our_examples}}
 
====Configure Your Project====
Whether you are  building a project from scratch, or adding Phidget functionality to an existing project, you will need to configure your development environment to properly link the Phidget libraries. To begin:
 
Create a new Xcode project:
[[Image:Cocoa_CreateProject.png |link=|center]]
 
 
Next, select an iOS application. For this tutorial's purposes, we will use a Single View Application:
[[Image:iOS_SingleView.png |link=|center]]
 
 
Name the project, select Swift as the language, and choose which devices will be supported:
[[Image:iOS_NameProject_Swift.png|link=|center]]
 
 
Now that your project is created, you need to add references to the Phidget iOS libraries. This is covered in detail above in the [[#Use our examples |use our examples]] section.
 
After you have linked the Phidget iOS libraries, simply add a reference to phidget22.h in your bridging header file:
<syntaxhighlight lang="objc">
#import "phidget22.h"
</syntaxhighlight>
 
 
Success! The project now has access to Phidgets and we are ready to begin coding.
 
==Write Code==
{{WriteCode_Intro}}
 
=== Step One: Initialize and Open ===
You will need to declare your Phidget object in your code. For example, we can declare a digital input object like this:
<syntaxhighlight lang="swift">
var ch:PhidgetDigitalInput? = nil
</syntaxhighlight>
 
 
Next, the Phidget object needs to be initialized and opened:
<syntaxhighlight lang="swift">
PhidgetDigitalInput_create(&ch)
Phidget_open(ch)
</syntaxhighlight>
 
 
Although we are not including it on this page, you should include error handling for all Phidget functions. Here is an example of the previous code with error handling:
<syntaxhighlight lang="swift">
var res:PhidgetReturnCode = EPHIDGET_OK
 
res = PhidgetDigitalInput_create(&ch)
if(res != EPHIDGET_OK){
  NSLog("Error")
}
 
res = Phidget_open(ch)
if(res != EPHIDGET_OK){
  NSLog("Error")
}
Phidget_open(ch)
</syntaxhighlight>
 
=== Step Two: Wait for Attachment (Plugging In) of the Phidget ===
Simply calling open does not guarantee you can use the Phidget immediately. To use a Phidget, it must be plugged in (attached). We can handle this by using event driven programming and tracking the attach events. Alternatively, we can modify our code so we wait for an attachment:
 
<syntaxhighlight lang="swift">
PhidgetDigitalInput_create(&ch)
Phidget_openWaitForAttachment(ch, 5000)
</syntaxhighlight>
Waiting for attachment will block indefinitely until a connection is made, or until the timeout value is exceeded.
 
 
To use events, we have to modify our code slightly:
<syntaxhighlight lang="swift">
PhidgetDigitalInput_create(&ch)
Phidget_setOnAttachHandler(ch, gotAttach, bridge(self))
Phidget_open(ch)
</syntaxhighlight>
 
Next, we have to declare the function that will be called when an attach event is fired - in this case the function ''gotAttach'' will be called.
 
<syntaxhighlight lang="swift">
let gotAttach: @convention(c)(PhidgetHandle?, UnsafeMutableRawPointer?) -> () = {phid,context in
    DispatchQueue.main.async(execute: {
        let myObject = Unmanaged<YourViewController>.fromOpaque(context!).takeUnretainedValue()
        myObject.onAttachHandler()
    })
}
</syntaxhighlight>
 
 
The bridge function mentioned above is described here:
<syntaxhighlight lang="swift">
func bridge<T : AnyObject>(_ obj : T) -> UnsafeMutableRawPointer {
    return Unmanaged.passUnretained(obj).toOpaque()
}
</syntaxhighlight>
 
=== Step Three: Do Things with the Phidget ===
We recommend the use of event driven programming when working with Phidgets. In a similar way to handling an attach event as described above, we can also add an event handler for a state change event:
 
<syntaxhighlight lang="swift">
PhidgetDigitalInput_create(&ch)
Phidget_setOnAttachHandler(ch, gotAttach, bridge(self))
PhidgetDigitalInput_setOnStateChangeHandler(ch, gotStateChange, bridge(self))
Phidget_open(ch)
</syntaxhighlight>
 
This code will connect a function and an event. In this case, the ''gotStateChange'' function will be called when there has been a change to the devices input. Next, we need to create the ''gotStateChange'' function:
<syntaxhighlight lang="swift">
let gotStateChange: @convention(c)(PhidgetDigitalInputHandle?, UnsafeMutableRawPointer?, CInt) -> () = {_,context,cState in
    var state:Int32 = cState
    DispatchQueue.main.async(execute: {
        let myObject = Unmanaged<YourViewController>.fromOpaque(context!).takeUnretainedValue()
        myObject.onStateChangeHandler(state)
    })
}
</syntaxhighlight>
 
Above, the onStateChangeHandler method is invoked on the main thread. Event data is stored as an Int32.
 
The method onStateChangeHandler is defined as follows:
 
<syntaxhighlight lang="swift">
func onStateChangeHandler(_ state:Int32){
    if  state == 0{
        stateLabel.text = "False"
    }
    else{
        stateLabel.text = "True"
    }
}
</syntaxhighlight>
 
 
If events do not suit your needs, you can also poll the device directly for data using code like this:
<syntaxhighlight lang="swift">
var state = 0
 
PhidgetDigitalOutput_getState(ch, &state)
stateLabel.text = state ? "True" : "False"
</syntaxhighlight>
 
=== Step Four: Close and Delete ===
At the end of your program, be sure to close your device.
<syntaxhighlight lang="swift">
Phidget_close(ch)
PhidgetDigitalInput_delete(&ch)
</syntaxhighlight>
 
== Further Reading ==
 
[[Phidget Programming Basics]] - Here you can find the basic concepts to help you get started with making your own programs that use Phidgets.
 
[[Data Interval/Change Trigger]] - Learn about these two properties that control how much data comes in from your sensors.
 
[[Using Multiple Phidgets]] - It can be difficult to figure out how to use more than one Phidget in your program. This page will guide you through the steps.
 
[[Polling vs. Events]] - Your program can gather data in either a polling-driven or event-driven manner. Learn the difference to determine which is best for your application.


[[Logging, Exceptions, and Errors]] - Learn about all the tools you can use to debug your program.
===Libraries===


[[Phidget Network Server]] - Phidgets can be controlled and communicated with over your network- either wirelessly or over ethernet.
{{AllQuickDownloads}}

Latest revision as of 21:39, 10 August 2023


We provide support for the Swift language on macOS. We also provide instructions on how to get your project started in Xcode for use in macOS and iOS applications. Select your operating system below, and follow the instructions to get your project running with Phidgets.

Once you have set up your development environment to run with Phidgets, we recommend you follow our guide on Phidget Programming Basics. The guide will showcase the fundamentals of programming with Phidgets.

Setup Guide

Swift - Select Development Environment

Select your Development Environment:

macOS

iOS

Language - Swift

Windows with Xcode

Welcome to using Phidgets with Swift! By using Swift, you will have access to the complete Phidget22 API, including events.

Xcode is an integrated development environment for macOS. It is commonly used as a tool for developing software for macOS and iOS applications.

Requirements

First, make sure you have the following installed:

● Phidgets Drivers for MacOS (see Part 1 of this user guide)

Xcode from the Mac App Store


You will also need to install CocoaPods in order to access the Phidget libraries for Swift. You can do this by opening the terminal and entering the following command:

Using Phidgets in Your Programs

There are two ways you can use Phidgets in Xcode. You can either start from a sample project provided by our code sample generator, or you can start a new project from scratch.

Select your preferred method below for instructions:

«
»

Language - Swift

Use Our Examples

Now that you have Xcode and CocoaPods installed, download a Swift example that will work with your Phidget:

Swift Examples

After opening the example, you will notice that there is a file called Podfile

Use Our Examples

If you open the Podfile, you can see that there is a reference to the Phidget22Swift pod. Note that no version number is included, so the newest available version of the Phidget22Swift pod will be installed:

Use Our Examples

To install the Phidget libraries, open a terminal at the example location and enter the following command:

pod install

Use Our Examples

After the libraries are installed, open the generated .xcworkspace file:

Use Our Examples

Next, simply press run:

Use Our Examples

Here is an example output:

You should now have the example up and running for your device. This would be a good time to play around with the device and experiment with some of its functionality.

Write Code

You should now have working examples and a project that is configured. This next teaching section will help you understand how the examples were written so you can start writing your own code.

Remember: your main reference for writing Swift code will be:

● The Phidget22 API Manual

● Swift example code

Write Code

Step One: Create And Address

First, create a Phidget object. For example, we can create a digital input object like this:

let ch = DigitalInput()

Next, we can address which Phidget we want to connect to by setting parameters such as DeviceSerialNumber.

ch.setDeviceSerialNumber(496911);

This guide won't go in-depth on error handling, but here is an example of the previous code with error handling:

do{
  try ch.open
}catch let error as PhidgetError{
  //handle error
}

Write Code

Step Two: Open And Wait For Attachment

After we have specified which Phidget to connect to, we can open the Phidget object like this:

ch.open(timeout: 5000)

To use a Phidget, it must be plugged in (attached). We can handle this by calling open(timeout), which will block until a connection is made, or until the timeout expires. Simply calling open() does not guarantee you can use the Phidget immediately.

Instead, you can verify the device is attached by using an attach handler. To use events to handle attachments, we have to modify our code slightly:

PhidgetDigitalInputHandle ch;
PhidgetDigitalInput_create(&ch);
ch.attach.addHandler(attach_handler)
Phidget_open(ch)

Write Code

Step Two: Open And Wait For Attachment

Next, we have to declare the function that will be called when an attach event is fired - in this case the function onAttachHandler will be called:

func attach_handler(sender: Phidget){
  let attachedDevice = sender as! DigitalInput
  //configure device here
}

We recommend using this attach handler to set any initialization parameters for the channel such as DataInterval and ChangeTrigger from within the AttachHandler, so the parameters are set as soon as the device becomes available.

Write Code

Step Three: Do Things With The Phidget

We recommend the use of event driven programming when working with Phidgets. In a similar way to handling an attach event as described above, we can also add an event handler for a state change event:

ch.attach.addHandler(attach_handler)
ch.stateChange.addhandler(stateChange_handler)
ch.open()

This code will connect a function to an event. In this case, the onStateChangeHandler function will be called when there has been a change to the channel's input.

Write Code

Step Three: Do Things With The Phidget

Next, we need to create the onStateChangeHandler function:

func stateChange_handler(sender: DigitalInput, state: Bool){
  if(state){
    //state is true
  }
  else{
    //State is false
  }
}

If you are using multiple Phidgets in your program, check out our page on Using Multiple Phidgets for information on how to properly address them and use them in events.

Write Code

Step Three: Do Things With The Phidget

If events do not suit your needs, you can also poll the device directly for data using code like this:

var state = ch.getState()
stateLabel.text = state ? "True" : "False"

Important Note: There will be a period of time between the attachment of a Phidget sensor and the availability of the first data from the device. Any attempts to get this data before it is ready will result in an error code, and a specific nonsensical result. See more information on this on our page for Unknown Values.

Write Code

Step Three: Do Things With The Phidget

Some Phidget devices have functions that deal with specific predefined values called enumerations. Enumerations commonly provide readable names to a set of numbered options.

Enumerations with Phidgets in Swift will take the form of Phidget22Swift.EnumerationType.enumerationName.

For example, specifying a SensorType to use the 1142 for a voltage input would look like:

Phidget22Swift.VoltageSensorType.PN_1142

and specifying a K-Type thermocouple for a temperature sensor would be:

Phidget22Swift.ThermocoupleType.K

The Phidget error code for timing out could be specified as:

Phidget22Swift.ErrorCode.timeout

You can find the Enumeration Type under the Enumerations section of the Phidget22 API for your device, and the Enumeration Name in the drop-down list within.

Write Code

Step Four: Close

At the end of your program, be sure to close your device:

ch.close()

What's Next?

Now that you've set up Phidgets in your programming environment, you should read our guide on Phidget Programming Basics to learn the fundamentals of programming with Phidgets.

Continue reading below for advanced information and troubleshooting for your device.

«
»

Language - Swift

Setting up a New Project

Whether you are building a project from scratch, or adding Phidget functionality to an existing project, you will need to configure your development environment to properly link the Phidget libraries. To begin, create a new Xcode project:

Setting up a New Project

Next, select a macOS application:

Setting up a New Project

Name the project, select Swift as the language, and continue:

Setting up a New Project

Now that your project is created, you need to add the Phidget libraries (using CocoaPods). Open a terminal at the example location and enter the following command:

pod init

Setting up a New Project

This will create a new Podfile. Open the Podfile in your favorite text editor and add a reference to the Phidget22Swift pod:

Setting up a New Project

Save your edit to the Podfile, and then enter the following command in the terminal which was opened at the example location:

pod install

Setting up a New Project

After running the command, open the xcworkspace file and access the Phidget libraries by adding the following line to the top of your files:

import Phidget22Swift

Success! The project now has access to Phidgets and we are ready to begin coding.

Write Code

You should now have working examples and a project that is configured. This next teaching section will help you understand how the examples were written so you can start writing your own code.

Remember: your main reference for writing Swift code will be:

● The Phidget22 API Manual

● Swift example code

Write Code

Step One: Create And Address

First, create a Phidget object. For example, we can create a digital input object like this:

let ch = DigitalInput()

Next, we can address which Phidget we want to connect to by setting parameters such as DeviceSerialNumber.

ch.setDeviceSerialNumber(496911);

This guide won't go in-depth on error handling, but here is an example of the previous code with error handling:

do{
  try ch.open
}catch let error as PhidgetError{
  //handle error
}

Write Code

Step Two: Open And Wait For Attachment

After we have specified which Phidget to connect to, we can open the Phidget object like this:

ch.open(timeout: 5000)

To use a Phidget, it must be plugged in (attached). We can handle this by calling open(timeout), which will block until a connection is made, or until the timeout expires. Simply calling open() does not guarantee you can use the Phidget immediately.

Instead, you can verify the device is attached by using an attach handler. To use events to handle attachments, we have to modify our code slightly:

PhidgetDigitalInputHandle ch;
PhidgetDigitalInput_create(&ch);
ch.attach.addHandler(attach_handler)
Phidget_open(ch)

Write Code

Step Two: Open And Wait For Attachment

Next, we have to declare the function that will be called when an attach event is fired - in this case the function onAttachHandler will be called:

func attach_handler(sender: Phidget){
  let attachedDevice = sender as! DigitalInput
  //configure device here
}

We recommend using this attach handler to set any initialization parameters for the channel such as DataInterval and ChangeTrigger from within the AttachHandler, so the parameters are set as soon as the device becomes available.

Write Code

Step Three: Do Things With The Phidget

We recommend the use of event driven programming when working with Phidgets. In a similar way to handling an attach event as described above, we can also add an event handler for a state change event:

ch.attach.addHandler(attach_handler)
ch.stateChange.addhandler(stateChange_handler)
ch.open()

This code will connect a function to an event. In this case, the onStateChangeHandler function will be called when there has been a change to the channel's input.

Write Code

Step Three: Do Things With The Phidget

Next, we need to create the onStateChangeHandler function:

func stateChange_handler(sender: DigitalInput, state: Bool){
  if(state){
    //state is true
  }
  else{
    //State is false
  }
}

If you are using multiple Phidgets in your program, check out our page on Using Multiple Phidgets for information on how to properly address them and use them in events.

Write Code

Step Three: Do Things With The Phidget

If events do not suit your needs, you can also poll the device directly for data using code like this:

var state = ch.getState()
stateLabel.text = state ? "True" : "False"

Important Note: There will be a period of time between the attachment of a Phidget sensor and the availability of the first data from the device. Any attempts to get this data before it is ready will result in an error code, and a specific nonsensical result. See more information on this on our page for Unknown Values.

Write Code

Step Three: Do Things With The Phidget

Some Phidget devices have functions that deal with specific predefined values called enumerations. Enumerations commonly provide readable names to a set of numbered options.

Enumerations with Phidgets in Swift will take the form of Phidget22Swift.EnumerationType.enumerationName.

For example, specifying a SensorType to use the 1142 for a voltage input would look like:

Phidget22Swift.VoltageSensorType.PN_1142

and specifying a K-Type thermocouple for a temperature sensor would be:

Phidget22Swift.ThermocoupleType.K

The Phidget error code for timing out could be specified as:

Phidget22Swift.ErrorCode.timeout

You can find the Enumeration Type under the Enumerations section of the Phidget22 API for your device, and the Enumeration Name in the drop-down list within.

Write Code

Step Four: Close

At the end of your program, be sure to close your device:

ch.close()

What's Next?

Now that you've set up Phidgets in your programming environment, you should read our guide on Phidget Programming Basics to learn the fundamentals of programming with Phidgets.

Continue reading below for advanced information and troubleshooting for your device.

«
»

Language - Swift

iOS with Xcode

Welcome to using Phidgets with Swift! By using Swift, you will have access to the complete Phidget22 API, including events.

Xcode is an integrated development environment for macOS. It is commonly used as a tool for developing software for macOS and iOS applications.

Requirements

First, make sure you have the following installed:

● Phidgets Drivers for MacOS on your development machine (see Part 1 of this user guide)

Xcode from the Mac App Store


You will also need to install CocoaPods in order to access the Phidget libraries for Swift. You can do this by opening the terminal and entering the following command:

Using Phidgets in Your Programs

There are two ways you can use Phidgets in Xcode. You can either start from a sample project provided by our code sample generator, or you can start a new project from scratch.

Select your preferred method below for instructions:

«
»

Language - Swift

Use Our Examples

Now that you have Xcode and CocoaPods installed, download a Swift example that will work with your Phidget:

Swift Examples

After opening the example, you will notice that there is a file called Podfile

Use Our Examples

If you open the Podfile, you can see that there is a reference to the Phidget22Swift pod. Note that no version number is included, so the newest available version of the Phidget22Swift pod will be installed:

Use Our Examples

To install the Phidget libraries, open a terminal at the example location and enter the following command:

pod install

Use Our Examples

After the libraries are installed, open the generated .xcworkspace file:

Use Our Examples

Next, select the type of device you would like the application to run on, and press play:

Use Our Examples

Here is an example output:

You should now have the example up and running for your device. This would be a good time to play around with the device and experiment with some of its functionality.

Write Code

You should now have working examples and a project that is configured. This next teaching section will help you understand how the examples were written so you can start writing your own code.

Remember: your main reference for writing Swift code will be:

● The Phidget22 API Manual

● Swift example code

Write Code

Step One: Create And Address

First, create a Phidget object. For example, we can create a digital input object like this:

let ch = DigitalInput()

Next, we can address which Phidget we want to connect to by setting parameters such as DeviceSerialNumber.

ch.setDeviceSerialNumber(496911);

This guide won't go in-depth on error handling, but here is an example of the previous code with error handling:

do{
  try ch.open
}catch let error as PhidgetError{
  //handle error
}

Write Code

Step Two: Open And Wait For Attachment

After we have specified which Phidget to connect to, we can open the Phidget object like this:

ch.open(timeout: 5000)

To use a Phidget, it must be plugged in (attached). We can handle this by calling open(timeout), which will block until a connection is made, or until the timeout expires. Simply calling open() does not guarantee you can use the Phidget immediately.

Instead, you can verify the device is attached by using an attach handler. To use events to handle attachments, we have to modify our code slightly:

PhidgetDigitalInputHandle ch;
PhidgetDigitalInput_create(&ch);
ch.attach.addHandler(attach_handler)
Phidget_open(ch)

Write Code

Step Two: Open And Wait For Attachment

Next, we have to declare the function that will be called when an attach event is fired - in this case the function onAttachHandler will be called:

func attach_handler(sender: Phidget){
  let attachedDevice = sender as! DigitalInput
  //configure device here
}

We recommend using this attach handler to set any initialization parameters for the channel such as DataInterval and ChangeTrigger from within the AttachHandler, so the parameters are set as soon as the device becomes available.

Write Code

Step Three: Do Things With The Phidget

We recommend the use of event driven programming when working with Phidgets. In a similar way to handling an attach event as described above, we can also add an event handler for a state change event:

ch.attach.addHandler(attach_handler)
ch.stateChange.addhandler(stateChange_handler)
ch.open()

This code will connect a function to an event. In this case, the onStateChangeHandler function will be called when there has been a change to the channel's input.

Write Code

Step Three: Do Things With The Phidget

Next, we need to create the onStateChangeHandler function:

func stateChange_handler(sender: DigitalInput, state: Bool){
  if(state){
    //state is true
  }
  else{
    //State is false
  }
}

If you are using multiple Phidgets in your program, check out our page on Using Multiple Phidgets for information on how to properly address them and use them in events.

Write Code

Step Three: Do Things With The Phidget

If events do not suit your needs, you can also poll the device directly for data using code like this:

var state = ch.getState()
stateLabel.text = state ? "True" : "False"

Important Note: There will be a period of time between the attachment of a Phidget sensor and the availability of the first data from the device. Any attempts to get this data before it is ready will result in an error code, and a specific nonsensical result. See more information on this on our page for Unknown Values.

Write Code

Step Three: Do Things With The Phidget

Some Phidget devices have functions that deal with specific predefined values called enumerations. Enumerations commonly provide readable names to a set of numbered options.

Enumerations with Phidgets in Swift will take the form of Phidget22Swift.EnumerationType.enumerationName.

For example, specifying a SensorType to use the 1142 for a voltage input would look like:

Phidget22Swift.VoltageSensorType.PN_1142

and specifying a K-Type thermocouple for a temperature sensor would be:

Phidget22Swift.ThermocoupleType.K

The Phidget error code for timing out could be specified as:

Phidget22Swift.ErrorCode.timeout

You can find the Enumeration Type under the Enumerations section of the Phidget22 API for your device, and the Enumeration Name in the drop-down list within.

Write Code

Step Four: Close

At the end of your program, be sure to close your device:

ch.close()

What's Next?

Now that you've set up Phidgets in your programming environment, you should read our guide on Phidget Programming Basics to learn the fundamentals of programming with Phidgets.

Continue reading below for advanced information and troubleshooting for your device.

«
»

Language - Swift

Setting up a New Project

Whether you are building a project from scratch, or adding Phidget functionality to an existing project, you will need to configure your development environment to properly link the Phidget libraries. To begin, create a new Xcode project:

Setting up a New Project

Next, select an iOS application. For this tutorial, we will use a Single View Application:

Setting up a New Project

Name the project, select Swift as the language, and choose which devices will be supported:

Setting up a New Project

Now that your project is created, you need to add the Phidget libraries (using CocoaPods). Open a terminal at the example location and enter the following command:

pod init

Setting up a New Project

This will create a new Podfile. Open the Podfile in your favorite text editor and add a reference to the Phidget22Swift pod:

Setting up a New Project

Save your edit to the Podfile, and then enter the following command in the terminal which was opened at the example location:

pod install

Setting up a New Project

After running the command, open the xcworkspace file and access the Phidget libraries by adding the following line to the top of your files:

import Phidget22Swift

Success! The project now has access to Phidgets and we are ready to begin coding.

Write Code

You should now have working examples and a project that is configured. This next teaching section will help you understand how the examples were written so you can start writing your own code.

Remember: your main reference for writing Swift code will be:

● The Phidget22 API Manual

● Swift example code

Write Code

Step One: Create And Address

First, create a Phidget object. For example, we can create a digital input object like this:

let ch = DigitalInput()

Next, we can address which Phidget we want to connect to by setting parameters such as DeviceSerialNumber.

ch.setDeviceSerialNumber(496911);

This guide won't go in-depth on error handling, but here is an example of the previous code with error handling:

do{
  try ch.open
}catch let error as PhidgetError{
  //handle error
}

Write Code

Step Two: Open And Wait For Attachment

After we have specified which Phidget to connect to, we can open the Phidget object like this:

ch.open(timeout: 5000)

To use a Phidget, it must be plugged in (attached). We can handle this by calling open(timeout), which will block until a connection is made, or until the timeout expires. Simply calling open() does not guarantee you can use the Phidget immediately.

Instead, you can verify the device is attached by using an attach handler. To use events to handle attachments, we have to modify our code slightly:

PhidgetDigitalInputHandle ch;
PhidgetDigitalInput_create(&ch);
ch.attach.addHandler(attach_handler)
Phidget_open(ch)

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Step Two: Open And Wait For Attachment

Next, we have to declare the function that will be called when an attach event is fired - in this case the function onAttachHandler will be called:

func attach_handler(sender: Phidget){
  let attachedDevice = sender as! DigitalInput
  //configure device here
}

We recommend using this attach handler to set any initialization parameters for the channel such as DataInterval and ChangeTrigger from within the AttachHandler, so the parameters are set as soon as the device becomes available.

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Step Three: Do Things With The Phidget

We recommend the use of event driven programming when working with Phidgets. In a similar way to handling an attach event as described above, we can also add an event handler for a state change event:

ch.attach.addHandler(attach_handler)
ch.stateChange.addhandler(stateChange_handler)
ch.open()

This code will connect a function to an event. In this case, the onStateChangeHandler function will be called when there has been a change to the channel's input.

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Step Three: Do Things With The Phidget

Next, we need to create the onStateChangeHandler function:

func stateChange_handler(sender: DigitalInput, state: Bool){
  if(state){
    //state is true
  }
  else{
    //State is false
  }
}

If you are using multiple Phidgets in your program, check out our page on Using Multiple Phidgets for information on how to properly address them and use them in events.

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Step Three: Do Things With The Phidget

If events do not suit your needs, you can also poll the device directly for data using code like this:

var state = ch.getState()
stateLabel.text = state ? "True" : "False"

Important Note: There will be a period of time between the attachment of a Phidget sensor and the availability of the first data from the device. Any attempts to get this data before it is ready will result in an error code, and a specific nonsensical result. See more information on this on our page for Unknown Values.

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Step Three: Do Things With The Phidget

Some Phidget devices have functions that deal with specific predefined values called enumerations. Enumerations commonly provide readable names to a set of numbered options.

Enumerations with Phidgets in Swift will take the form of Phidget22Swift.EnumerationType.enumerationName.

For example, specifying a SensorType to use the 1142 for a voltage input would look like:

Phidget22Swift.VoltageSensorType.PN_1142

and specifying a K-Type thermocouple for a temperature sensor would be:

Phidget22Swift.ThermocoupleType.K

The Phidget error code for timing out could be specified as:

Phidget22Swift.ErrorCode.timeout

You can find the Enumeration Type under the Enumerations section of the Phidget22 API for your device, and the Enumeration Name in the drop-down list within.

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Step Four: Close

At the end of your program, be sure to close your device:

ch.close()

What's Next?

Now that you've set up Phidgets in your programming environment, you should read our guide on Phidget Programming Basics to learn the fundamentals of programming with Phidgets.

Continue reading below for advanced information and troubleshooting for your device.

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