The following guide is a tool to aid in adapting a toy to be compatible with an assistive switch without instructions specific to that toy. Basic knowledge of wiring, electronics, and soldering will be beneficial for adapting toys. This guide will suggest wiring configurations and tutorials for other toys that may be a useful reference. How to install mono jacks, soldering to switches and additional tips are also included.
Switch adapted toys are toys that can be activated or controlled with accessible switches. If a user wishes to play with a toy that has small or difficult to push buttons, and cannot easily interact with the toy’s interface, switch adapting the toy is a solution to make it more accessible. Purchasing switch adapted toys commercially can be expensive so adapting regular toys is often more economical.
Selecting a Toy
When selecting a toy to switch adapt, the Makers Making Change assistive devices webpage can be reviewed to search for toys the user may be interested in that already have instructions written. If the user wishes to play with a toy that is not listed, the rest of this guide will help in the adaption process. A toy with a few regular buttons work best for switch adaptions. Inspect the toy to see if all its functions are controlled with regular buttons. If any of the toy’s functions are activated with voice command, motion activation, capacitive touch or other more complicated controls, the toy will be difficult to adapt and a simpler toy should be selected.
Tools and Supplies
There are a few common tools and supplies useful for adapting toys. Not all tools and supplies listed are required for all toy adaptions but generally soldering supplies, a screwdriver, wire, wire strippers, mono jacks, and a drill are required at the minimum.
Choosing a Wiring Diagram
The following wiring diagrams show what the toy’s wiring may be and how the wiring can be changed for adaption. Use the flow chart in the Choosing a Wiring Diagram section to determine which diagram to reference.
Battery Interrupter Wiring
Battery interrupters are quick and useful when switch adapting simple toys with one button. The battery interrupter can be installed as depicted below, between the battery and the battery compartment wall. Plug a switch into the battery interrupter and turn the toy on using its original button. When the accessible switch is pressed, the current will be able to travel through the entire circuit and the toy will be activated. Instructions on how to make and use battery interrupts can be found in the assistive devices section on the website.
Wiring Diagram A
The original wiring shows a single button, a battery compartment and a motor/light/speaker, depending on the toy. In the adapted wiring, the switch works to control the toy only once the original button has been turned on.
Wiring Diagram B
The original wiring diagram has one button which is essentially the on/off button, as well as a battery compartment and a motor/light/speaker, depending on the toy. The adapted wiring shown allows the new switch to act as the on/off button.
Installing Mono Jacks
Mono jacks used for switch adapting toys have three legs and a threaded piece with a nut. Wires should be soldered to the middle leg, and the leg closest to the threaded side as shown in the photo.
Installing an Internal Mono Jack
If there is room, the mono jack can be installed inside a toy. Simply drill a ¼” hole through the toy’s shell and remove any rough edges with a craft knife to create a clean hole. When drilling, try not to point the drill bit towards any delicate internal components. A spur-point drill bit works well for drilling in plastic. Once the hole is drilled, remove the nut and push the threaded side of the mono jack through the hole. Secure in place by reinstalling the nut on the outside of the toy.
Installing a Mono Jack External to the Toy
If there is no room to install the jack directly in the toy, a box can be 3D printed to hold the mono jacks.
If this method is selected, a hole must be drilled in the original toy so that wires can exit the shell. The size of this hole will vary depending on the number of wires that are used, generally it will be less than ¼”. A tight fit may be preferred for wire integrity. If this method is used, heat shrink wire wrap may also be beneficial in keeping the wires organised.
Thread the box lid onto the wires then solder the wires to the mono jack. The mono jack can then be installed in the 3D printed box in the same manner as an internal mono jack. An example of this is shown in the figure below, the wires wrapped in heat shrink wrap exit the toy egg, and enter the 3D printed box that holds the mono jacks.
The original buttons for many toys are simple switches similar to the one shown. Each leg of the switch will have a soldered connection.
Some toys also have a switch directly in the circuit board. When the button on the outside of the toy is pressed, a pad will be pressed onto the circuit board, and the switch is closed. To adapt these switches, a wire needs to be soldered to each half of the switch. The wires cannot touch the other side of the switch, or the toy will constantly go off. The arrows in the picture indicate the two halves of the switch.
If these types of switches are used but you cannot solder to it due to the lack of exposed copper, follow the lines on the circuit board to determine if there are nodes that can be soldered to. Test these nodes before you solder to ensure they are correct in controlling the switch.
When opening the toy, keep the packaging in the best condition possible. Repackage the toy after the adaption so that the user gets the “new toy” experience of opening a brand new toy.
Sometimes the most difficult part of a hack can be opening up the toy. Once all visible screws have been removed, use a screwdriver to try and gently pry the parts of the toy apart. It is a good idea to place all removed parts and screws into a cup or similar container throughout the adaptation so no parts go missing. If there are many parts, it is also a good idea to take pictures of the toy as you disassemble. This will act as an aid when putting the toy back together again so all parts will be reinstalled in their original position.
It is important to wear safety glasses as eye protection when completing toy hacks. You do not know what little springs or screws or plastic parts will fly out of the toy unexpectedly.
Electrical tape should also be kept on hand to insulate wires that have the possibility of touching. This will ensure there are no problems with wires touching once the toy is put back together.