In this Instructable I am going to cover how I built floor switches for an installation. There are a lot of amazing tutorials on how to make floor switches, but I wanted to try and make it as modular, cheap, replaceable, washable as possible using the least amount of material. Hope you find this tutorial useful! Thank you!
Step 1: Gathering Materials!
To make these interactive mats/floor switches, you will need the following materials (of course you can replace a lot of these materials for other things you like or have handy. The materials below were chosen because they are affordable and widely available):
Solid Grip Non-Adhesive Shelf Liner, 20 in x 4 ft roll
Grip Easy Liner Non-Adhesive Shelf Liner, 20 in x 24 ft roll
Conductive Cloth Fabric Tape, 30mm roll
- Stranded Twisted Pair Hook-Up Wire, 24 AWG, 100' Size (Go ahead and judge me! I used to always twist my own wires the "fun hand drill way", but you know what?! I'm OVER it!)
- Velcro Tape, 3/4 in Roll
RazorEdge Micro-Tip Easy Action Shears, 5 in (The best craft scissors EVER. You are welcome.)
Metal button snaps, 10mm (any will do, you can find them at any craft store)
- Electrical Terminal O-Ring (also easy to find at a local hardware store)
- Silver or light colored permanent marker (my go to is a silver Sharpie)
- A soldering station is needed in order to solder the wiring to the o-rings and you might want to pick up whatever connectors you need for your specific installation, I was connecting these mats to an Arduino & Raspberry Pi so I just used female headers I had laying around.
Multimeter, is nice to have to test the connections but not imperative
Now that you have gathered all the materials, let's get building!
Step 2: Cutting the Mats to Size
I decided to use these drawer liners because they are cheap, easy to find at local stores, non slip (and since they will be on the floor that is important!) and easy to wipe clean. I wanted to get away from having to enclose the mats in fabric or other types of outside liners so as you will see the insulating material in between the two outer layers is also going to be used to hold the whole mat together. I was aiming at using the least amount of material possible in this design.
I chose to make my mats about 13in x 20in and cut a piece of insulator material about 18in x 28in (I end up trimming it slightly later on, and of course you can make these mats any size your project requires!)
Step 3: Laying Down the Conductive Tape
When making the switch, you want to lay down the conductive fabric tape in different patterns.
On one side we will lay down a few vertical strips (in this case 7) and then connect them all with one horizontal strip.
On the other half of the mat we will lay down horizontal strips (5 in this case) and then connect them all with one vertical strip.
If you have a multimeter handy you can probe the conductive tape to make sure that all points are properly connected.
Step 4: Adding the Snaps
I got the idea about using the combination of button snaps and o-rings from LessEMF and I would have loved to buy theirs but I was in a rush and needed something in a pinch so I just went ahead and got the components separately from local sources.
I used some conductive tape to wrap around the back of the mats so the connectors would sit on the outside and would be easier to access. I then put the bottom snap piece down and covered it with a piece of tape to keep it in place and make a solid contact, you can make a small hole in the fabric tape to let the snap piece poke through.
Make sure that you can still button it, as you will be putting the o-rings in between the two snap pieces a little bit later.
Step 5: Cutting the Insulating Layer
You can chose any material you like as insulator in between your switch, I personally love this drawer liner because it's already a grid, it is super easy to cut (and also feels very rewarding to cut! The small joys...) and you can see through it. It is also the perfect thickness to separate the two outer layers.
Take the piece of insulating material and mark the corners so you will be able to align the outer layers consistently. Then looking at the grid you made with the tape on both sides of the mat, design the grid that you want. I find the pattern pictured here to work really nicely. If there are dead spots where you step and nothing happens, you can go back and add a couple of more holes to make the mat more sensitive.
Design the grid and make sure that the holes align with the tape on both sides of the mat so when you step on it the two outer layers will come into contact with each other and close the circuit.
I am famous for winging things pretty well, but please feel free to improve on this system by actually making some kind of standardized template for the insulator grid. I have been eyeballing it as that's more my style :)
Step 6: Fastening the Insulator With Velcro
Now that you have your middle layer cut and ready to go, we are going to use it to hold the mat together. First I cut the corners out, because we don't need those and they will actually get in the way as we will be folding it over.
After cutting out the four corners and discarding that material, I cut the overhang into smaller flaps which we can fold over and attach with velcro to the outside of the mat in an alternating sequence. This will allow the mat to stick together and also thanks to the velcro it will allow you to replace the insulating material if over time it gets worn out without having to disassemble or remake the entire mat.
Alternating, fold over some of the overhang over one side of the mat and attach using velcro. Then flip the mat over and work on the other side.
Voila'! The mat should now all be one piece!
Step 7: Soldering Materials
For this step you will need a soldering iron, solder, wire strippers, twisted wire (or non twisted), the o-rings which you will use to wire up the mat and whatever connector you want to use on the other side of the wire, depending on what you are going to plug the mat into. As I mentioned before I used female headers so that I could plug these mats into a RaspberryPi.
Step 8: Soldering the Connectors
Using helping hands or any other method you prefer, solder the wires through the o-rings to make a strong connection.
On the other ends of the wire, solder any type of connector that suits your application (and yes, for some soldering I use fancy helping hands but mostly I LOVE just taping things down while soldering, that's my thing).
Now you have the wiring ready to go!
Step 9: Finishing the Assembly of the Mat
Lift the pieces of material that are covering the button snaps and snap the o-rings in between the snap pieces.
Cover back with the velcro-ed pieces.
Flip and repeat!
Step 10: Decorating Time!
I decided to buy some interesting mats to cover the switches with, to add some color and patterns but also because I thought this way it would be easy to wash the top layer separately without impacting the switch.
Using a vinyl cutter you can make (or you can buy online) foot prints stickers to visually communicate where and how to step on the mats.
We have been using our mats around the office for months now and I have not had to replace any parts yet!
Decorate your switches however you like! Hope you found this tutorial useful. Enjoy stepping on your new interactive mats!
Step 11: Video
In this video you can see a time-lapse of the whole mat building process! Thank you for watching!