Adapted PC Mouse

Here is a summer project you can do if you need to attach a single switch to a mouse but lack the funds for the switch interface. A single switch acts as the left mouse button and enables an individual with limited motor skills to access the computer and software.

The cost for an off-the-shelf, single switch interface is about $100. You can adapt a mouse yourself so that a single switch can be plugged into it. This do-it-yourself project will allow you to spend your budget on other needed items.

The cost of supplies in the following list will save you money even if you have to buy the necessary tools (i.e., soldering iron and drill). Try to borrow them though, if you don't happen to do much soldering or drilling. Who knows, the person you borrow the tools from may offer to help.

Materials

• Two-button Mouse (one you are not going to need if this experiment does not work)
• Screwdriver
• Soldering Iron
• Solder
• 1/8" Sub Miniature Jack
• Crazy Glue
• Wire Cutters
• Drill and drill bits
• Sharpie (Fine-point, permanent marker)
• Multimeter

Instructions

Phase I - Pullin' it Apart

1. Remove screws from the base of the mouse so you can lift the top and see inside
2. Use the Sharpie to mark the switch (small black box) which corresponds to the left button
3. Remove the circuit board from the base of the mouse
4. Turn the board over so that you can see the soldered side of the circuit board
5. You need to identify which two pins are the active ones by using the multimeter
6. Mark those pins

Phase II - Makin' a Mess

7. Get two pieces of wire
8. Strip one end of each wire
9. Solder one wire to each of the pins you just marked
10. Examine your mouse and determine where the jack will best fit. (Try to find a place where the jack will not interfere with any other wires or moving parts. Also make sure the jack is not going to prevent the circuit board from being reinserted.)
11. Drill the hole for the jack (start small and work up to a ¼" bit)
12. Insert the jack to check fit
13. Remove the jack
14. Cut the wire so that you will have enough to reach the jack and a little extra (about ½" extra, not a lot because you are working within a small area)
15. Strip the ends of the wires
16. Then solder each wire to jack

Phase III - Puttin' it Together

17. Insert the jack
18. Reinsert the circuit board
19. Tuck the wires in so they are not in the way of any moving parts (you may want to use a dab of Superglue to hold the wires in place)
20. Try out your mouse!

Special thanks to Mike Birkmire of LINC for teaching us how to adapt a mouse.