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Switch Interfaces

You can't plug a switch straight into a computer. Not even into the microphone port, though I've seen many people try. In order to use your switches you need to invest in a switch interface.

Switch Connection Diagram

There are three common types of switch interface:

  1. Serial Interface
  2. Games Emulator (USB)
  3. Keyboard Emulator (PS/2 or USB)

Serial Switch Interfaces

For many years the method of attaching switches to a computer involved the old serial port, but there were various disadvantages to this. We were limited to using a maximum of two switches, we had to select the correct COM port in every switch game or application we used. Also voltage problems led to switches failing on fairly regular intervals. Modern laptops often do not have serial ports.

Serial Switch Interface

Sensory Software's serial Switch Interface

These cheery little interfaces are small, very cheap, and great for attaching up to two switches to a computer that has a serial port. Many modern computers - especially laptops - no longer have serial ports.

Games Emulator

Fortunately a few years back along came the modern age of switch access: via the reliable USB port. In this case a switch or multiple switches emulate a games joystick and this information is accepted either directly by modern switch-accessible software like Clicker 5 or via a Switch Driver for older programs, or programs not specifically designed to be driven by switches.

The USB devices are far more robust, reliable and flexible but as a manufacturer has to pay a licence to use USB they are significantly more expensive. Also unlike the serial interfaces you can't make them yourself with a few bits of wire and a soldering iron.

JoyCable Switch Interface

Sensory Software's USB JoyCable

This is a simple modern equivalent to Sensory's older serial switch interface. It allows a maximum of two switches to be attached to a computer's USB port. The JoyCable comes with Sensory's flexible Switch Driver software that allows the USB interface to be used with older switch-accessible software.

JoybBox Switch Interface

Sensory Software's USB JoyBox

The JoyBox is similar to the JoyCable but allows for up to twelve switches to be attached.


Wireless Switches Switch Interface

Sensory Software's USB Radio Switch Interface

Sensory's radio switch interface is perfect for wheelchair users who use their switch to access a shared computer. Physically attaching a wheelchair to a computer via a cable often leads to entwined cabled and panic for which the radio switches are an effective solution.

Crick USB Switch Interface

Crick USB Switch Interface

This is a good and reliable method of attaching up to four switches to your computer. The USBKeys 2 software that comes with this device is fantastic and even automatically sets up your switches for a variety of programs (not just Crick's either).


A regular games Joystick or Gamepad

Well you never know! If you use Sensory Software's Switch Driver you can use the motion of the joystick to move the mouse pointer or the text caret. You can also use the buttons as regular switches.

Joysticks have never been the most robust devices, but gamepads can generally take a bit more stick. Plus with all the practice some pupils get at home they could surprise you with their expertise!

You can't plug switches into any mainstream gamepads or joysticks that I know of.

Keyboard Emulators

Finally we have switch interfaces that emulate keyboard input through PS/2 (or sometimes confusingly) through USB. This differs from the USB Switch Interfaces that emulate a games joystick and therefore compatibility is affected.

Don Johnston Switch Interface

Don Johnston Switch Interface Pro 5.0

This switch box connects via USB to either a Windows or a Mac computer and requires no special software to run. All configuration is done on the unit itself using a small button on the top and although this can limit its versatility, the four function sets built-in to the unit are more than adequate for most users. Because it uses no software it is easier to use and should be less likely to go wrong!

Because this is not a games-joystick-emulating switch box you cannot use it with programs that only accept that type of input. This, rather unfortunately, includes the popular Clicker 5.

IntelliKeys Keyboard


The IntelliKeys has two standard switch inputs on the side of the keyboard.

Further information is available on my IntelliKeys page.