About switch access
Switch access is an input method that uses any movement a user can do, to activate a contact switch which then, via a switch box, activates a particular action on the tablet.
There are a few things that you need to be aware of with switch access. The first, and most important is that the action you are trying to use to activate the switch, for example, a push with a hand or foot, a nudge with a head or a blow on a pneumatic switch, needs to be both intentional and consistent.
Some practitioners can make the mistake of putting a switch near to someones hand, where with a lot of concentration and effort, they can press it 50% of the time. Whilst this is a big gain over no access to their tablet, it may be that they can move their foot much more easily, or a knee movement is more consistent, if that is the case, then you should look at utilising that movement as the switch function, rather than just going with the obvious movement. They key is to look at the body of the person you are trying to support as a whole, and identify what movement can be repeated consistently and with minimal effort, after all we are trying to make access to the tablet as easy as possible!
Once you have identified the movement you need to decide the best way to capture that movement and use it to activate a switch.
Most switch access movements are going to be limb (arm and leg) or head movements. With limb movements, which can include fingers and toes, and head movements, the easiest way to capture these is with Jelly Bean switches.
Jelly Beans are the workhorse of switch access. They are standard push-to-make contact switches and they have been used for many years in the SEN and AAC market. They come in a range of sizes if you need a bigger target area, but more importantly they do come with mounting options. In the black flange around the base of the switch, there are three screw holes, so the switches can be screwed to mounts and permanently fixed to wheelchair trays and surfaces. However most switch users are going to need to use their switches in different locations and in different settings, so permanently fixing them isn’t always the best idea. This is where velcro becomes invaluable, a small square of loops on the switch and another square of hooks on the surface you want to mount the switch to, and you’re away! Velcro can be particularly useful if you are assessing a user too, as you can quickly and semi permanently attach switches in positions to see if they work for the user you are assessing.
As well as Jelly Bean switches there are a range of switches from Pretorian called Smoothie switches. These are sold by most of the SEN and AAC suppliers in the UK as they are very versatile and often less expensive than Jelly Bean switches. They look very similar to the Jelly Bean switch and also come with mounting holes, and can also be attached to surfaces with velcro.
There are may types of physical movement switches on the market, and they all rely on the user making a particular movement to activate them, the table below outlines some of the most common switches and the movement that is required to activate them.
As well as the switches that work on physical movements there are also a range of switches that work on less obvious functions. Most common is the pneumatic switch. The pneumatic switch, often called a sip/puff switch, is activated by the user sucking (sip) or blowing (puff) into the switch. These can be particularly useful if you are working with users who have no movement but can control their breath.
If you find that you are working with a user who cannot control their movements or their breath, often users with very high spinal injuries who are ventilated, you may find that you need to use a blink switch.
Blink switches are activated by the user blinking their eyes. A small invisible beam is sent out from the sensor, and reflects off of the surface of the eye, back to a receiver. Once a user blinks, the beam reflection is broken and the switch registers this as an activation. It is with noting at this point though if a user is at a level where their impairment requires a blink switch, they may be more suited to using an eye gaze system.
After you have chosen the switch that is most appropriate to the movement that you are going to be harnessing, you need to think about the switch interface, often called ‘the switch box’.
Switch interfaces for tablets generally connect via bluetooth, and will pair in a fairly similar way. First you will go to the settings of your tablet, and then turn on it’s bluetooth. You will then put your switch interface into pairing mode, which is always detailed in the instructions, but does vary from interface to interface.
Once it is paired you can plug your switch into it and start to use it. Sounds simple, right? However in practice it is slightly more complicated and there are some things that you need to be aware of!
The technical part of what is happening when you pair a switch interface is interesting. Each switch interface is emulating (pretending to be) a bluetooth keyboard, and what it is actually doing when you press the switch is sending our a keystroke, the same as if you were pushing a letter, number or punctuation mark on a bluetooth keyboard! In fact you can actually access most switch access functionality with a bluetooth keyboard!
With this in mind it is important to know what your bluetooth switch interface is sending out. For example the Therapy Box Switch Box sends out two codes, it uses tilde combined with a 1 or 3, so when you press the switch the interface sends either ‘~1’ or ‘~3’ to the iPad.
This works with all of Therapy Box’s own apps, but may not necessarily work with other switch access apps that you want to use. The reason for this is that each of the apps can decide what keystroke they are looking for, to make them perform the action. Unfortunately there is no standardisation of this code system, so you may end up with numerous boxes!
For this reason, we recommend the Pretorian APPlicator.
The ‘Applicator’ switch box is unique in that is is deigned to be programmable. With the ‘Applicator’ you can choose what keystrokes it is sending out with each switch press. With the ‘Applicator’ you have 24 different keystrokes and codes that can be sent to the iPad, and you can plug in up to four switches, allowing you to access four functions at once.
Using the Switch Access Method – Pairing
So now that you have your hardware sorted, you have chosen your switch interface and the switch that you are going to use to capture the user’s movement, you can start to look at how the hardware is going to connect together and work with the iPad.
The first thing that you need to do is to pair the switch interface with the iPad.
To pair the interface, in this instance the Pretorian Applicator, you first need to go to the settings on your iPad, and then to Bluetooth, and ensure that it is switched on.
You then need to turn on the Applicator by pressing any button on the face of it. After a few seconds the APPlicator should appear on screen as a discoverable device. It will have a name similar to;
Once you can see this name on the screen of your iPad, tap it, and then the pairing process will start. It typically takes around 20 seconds for pairing to take place, and once it has happened the iPad will show the ‘Applicator’ as connected, your applicator is now paired, and after you have plugged in your switch, it is ready to use.
By default the ‘Applicator’s’ four ports are configured as follows and will send the following key strokes:
qPort 1 – ‘Space’
Port 2 – ‘Enter’
Port 3 – ‘~1’
Port 4 – ‘~3’
Although these are configurable and we will go into that later, but for now, those four emulated strokes should get you up and running pretty quickly and effectively!
The first thing you need to do once you have paired your switch interface with your iPad is to decide whether you are aiming to control the whole iPad and apps with the switches or whether you are going to just control apps.
In this tutorial we are going to assume that the user you are working with wants to use both the iPad itself and the apps that are switch accessible.
Using the Switch Access Method – Controlling the iPad
To start using the switch interface and switches with the iPad we need to first tell the iPad that this is how we are going to access it. To do that, we first need to turn on switch control, and this is done by tapping on the settings button, then general, then accessibility. Within accessibility you need to scroll down and and go to switch control and then turn it on.
There are lots of settings within the switch control options, we will get on to those a little later, as they are for adjusting the behaviour of the switch control, and aren’t necessarily needed right away to get you up and running. They are more for fine tuning the system to make it optimal for the person using it.
You will see in the next video that as soon as you turn switch access on, the default setting is auto scanning. The iOS will use a highlighted bar to start to scan down the icons row by row. Once you get to the row that you require, hit the switch and it will start scanning across the columns, once you get to the icon you want, press the switch again to select it.
This process of scanning rows first, and then columns is called column and row scanning, and is the most common scanning technique used in switch access!
It is as simple as that to start basic scanning access on the iPad with a single switch. You may find that these default settings work for most users, but assuming that they don’t, lets look now at the switch settings and see how we can use them to adjust the switch access to be as beneficial to the user as possible.
Using the Switch Access Method – The Settings
At this point we suggest that you watch the next video which takes about ten minutes and then refer to the text below as a reference. If you want to use ‘Proloquo2go’ then see the video at the end of this section.
Within the menu settings, general and then switch access, you are presented with a screen full of settings that can adjust the switch access on the iPad.
The first is switch control, and this is a simple on/off toggle, this tells the iPad whether you want to use switch access or not. If it is on, the switch access starts, if it is off, it doesn’t, simple really!
The next option is the Switches option, which has a number at the end of it. This number at the end indicates how many switches are being used to control the iPad.
If you tap on this option it will take you into the switch setup screen. From the setup screen you can choose to add a new switch. When you have tapped on the set up new switch bar, you can choose whether you are going to use an ‘External’ (switch interface) ‘Screen’ (the screen as a single touchpad) or ‘Camera’ (a head tilt tracking switch using the iPads camera, which is not very reliable!).
For now we are going to concentrate on external switches, so tap external and then it will ask you to activate your external switch. Some switch interfaces aren’t very good at distinguishing between the switches that are plugged into them and may tell you that the source is in use if you already are using another switch on the same interface. This is another reason why we recommend the ‘Applicator’, it does not have this issue. Once you have activated your switch, you can then choose the action that you want to assign to it.
The next block of settings affect the timing of the switch access method. The first setting is the Auto Scanning Time, this is the amount of time that it waits before the move to the next row or column, this time should be made larger if you find that the user is missing the icons because the scan is not waiting on it for long enough as you will see in the following video.
The next setting is called Loops and is detailed in the next video. This setting tells the scanning process how many times it should loop around, either all of the rows, or the columns within a row before it stops and returns to the start position, usually the top of the screen. This setting can be particularly useful if you are working with people who will forget that the dotted line means ‘go back’ or ‘come out of this row’.
After that we have Auto Tap. When auto tap is turned on, performing the selected action will automatically ‘tap’ the screen, unless select is pressed twice to bring up the menu of actions. This is a setting that has little use if you are using simplistic switch access where a switch is the button you are selecting with, however it is worth knowing that the setting is there incase you ever need it for advanced users who want to make use of the other specialist functions that are available.
Move Repeat is the next setting, and initially it is an on/off toggle. If you toggle the setting to on, it allows you to choose the repeat move time. This time is the amount of time the iPad will wait before it starts moving the selection again, if the switch is being held down. This can be useful if you are working with people who have difficulties releasing the switch once it is activated.
Hold Duration, the next setting is nice and simple. It is a setting that allows you to choose the amount of time the switch needs to be activated before it registered the activation. This is extremely useful for people with erratic movements, you can set it to a time that ignores accidental activations, and focuses solely on activations that are longer than a certain time.
Ignore Repeat works in a similar way to hold duration, except that with ignore repeat you are choosing the amount of time between repeats that are allowed. For example, if you are working with someone that has a tremor, they may activate the switch 5 times in a second. This is not good if they have a movement time of 1 second, as they have pressed the switch 5 times before the scanner moves to the next step! If this is the case you can use ignore repeat to act as a buffer, you can tell it to ignore further activations after the first one, for a set amount of time. With adjustment and a bit of testing, you an eliminate a lot of the inconvenience of tremors and multiple presses.
The next option you can adjust is the ‘Glide Cursor Speed’. This is the speed which the cursor moves across the screen. Have a play with it and set it so that it suits your user’s visual preferences.
The next two settings are for audio. If you are using switch access with a user who has a visual impairment you can use audio to indicate where they are in the scanning, and when each scan movement has happened.
First you have Sound Effects which are sounds that indicate movement of the scan and scan actions, these are simply toggled on and off. The second option is for Speech, this uses the voiceover functionality, mentioned in other modules, to read out the screen as it is scanned. This can be particularly useful to users with visual impairments who need to read a lot of text.
The next item is Included Menu Items. This setting allows you to choose what items are shown in sub menus when an item is clicked. It contains things like the home button, scrolling and gestures, which may be useful for high level users. However for most users turning these options off is the most appropriate course of actions, as for most users the extra features that they open up, aren’t offset by the amount of confusion that they can cause!
The next two settings are under the Visual heading. They are large cursor and cursor colour. The larger cursor on/off toggle allows you to choose whether you are using a large cursor, if you turn it on, the selection line around the scanning becomes thicker, and easier to see. Then you can choose the colour of the section with the cursor colour option. You can tailor this to a colour that your user most likes, or one that is easiest for them to see. These settings are most commonly used with people who have slight visual impairments, and people who want to customise their support to be aesthetically pleasing!
The last setting is for saved gestures. These are onscreen gestures that can be used as shortcuts and aren’t useful for people using external switches. However if you are working with someone who is using the screen as a switch, you could record gestures to perform specific actions.
Lots of other apps have switch access methods, and there are far too many of them to list individually, however reassuringly they all rely on similar methods and have similar settings to the iOS switch access.
You will find that most of the SEN and AAC apps have their own form of switch access built in, but many of the free apps that we use don’t. The iOS scanning has come a long way to address this issue, but it is a case of trial and error to see which apps work with switch access and which don’t.
So far we know that the following apps are fully switch accessible, and we will add more as we find them!
Predictable from Therapy Box
Scene & Hear from Therapy Box
Proloquo2go from Assistiveware