Introduction: Pokemon Detecting Wristband
Want to be able to hunt and find Pokemon hiding in the real world? Now you can with your own Pokemon detecting bracelet*!
*Not to be confused with the Pokemon GO Plus bracelet. Sometime this year (2016), the Pokemon GO project will go live where you will be able to "hunt" and "capture" Pokemon in the real world using augmented reality and your smartphone. They have also come up with a bluetooth enabled Pokemon GO Plus bracelet that will notify the user with vibration and LED that a Pokemon is nearby, even if they aren't looking at their phone.
I wanted to pay homage to the Pokemon GO project and created my own Pokemon detecting wristband that will light up and vibrate when a Pokemon toy is near the user's wrist. It is made from old party favors that my daughters received at a birthday party three years ago. I managed to confiscate one of their wristbands and a handful of the small plastic toys and squirrel them away for a rainy day project. I didn't know what project I was going to use them for at the time, but when I came across the stash last weekend, I knew I had just the thing I wanted to try with it: sewable circuitry!
Step 1: Things You Will Need to Acquire Before You Can Hunt Wild Pokemon.
You'll need for this project:
Small plastic pokemon toys
2 coin cell batteries
blinky LED (with negative lead painted black with a sharpie marker)
sewing needles and regular non-conductive thread
scrap fabric to sew the circuit on
jewelry pliers for curling the ends of the LED and reed switch into loops
Step 2: Circuit Planning and Testing.
I've drawn up the simple circuit and how the placement of the components on the scrap fabric should look like to avoid unintentional touching of the conductive tape paths. I also sketched this with black marker on the scrap fabric piece as well, after I checked that the circuit worked using alligator clips on the components and applied a magnet near the reed switch.
Step 3: Sewing the Circuit and Components in Place.
Following my sketch, I placed the conductive tape on the scrap fabric, double checking along the way with the components to see if the spacing was still correct. Where the conductive tape had a slight angle to its path, be sure to NEVER cut the tape to make the angle. You'll need to fold the tape back on itself to keep the path one piece and continuous. The sticky side of the tape doesn't conduct electricity and therefore you would have a broken circuit if you cut it into two pieces and laid them on top of one another at an angle.
I machine sewed the tape in place (even if they seemed pretty securely stuck to the fabric) with normal thread and I hand sewed the components with conductive thread. Even when all I had available was the "wrong" type of conductive thread, it still worked by securing the metal ends of the pieces tightly against the conductive tape for a good connection.
What I mean by the "wrong" type of conductive thread is the softer 2-ply type that is used for sewing pads onto the fingertips of gloves for conductivity against touch screens, has too high of resistance to get enough power to the components. If I had the correct 3-ply type of conductive thread, I could have just sewed running stitches to each of the components instead of using the conductive tape. But I figured out how to use what I had on hand, instead of buying the right thread for the purpose.
Step 4: Testing Phase: Does It Work?
So the moment of truth--does the circuit work when a magnet is placed near the switch? Yes! The LED is blinking its rotation through red, blue and green, and the motor is humming and vibrating strongly.
Step 5: Sewing the Circuit to the Inside the Wristband.
To stick the fabric circuit inside the wristband, the wristband needs to be cut around the inside circumference and opened up and turned inside-out, so the back of the pokeball patch is now facing out. The center of the pokeball patch also needs to be cut open enough to fit the LED through.
I inserted the LED light into the cut-out center of the pokeball patch, and did a running stitch with normal thread up and down the long sides of the fabric circuit to keep it from shifting inside the wristband. I left the short sides of the scrap fabric un-sewed to the wristband, in case I needed to get my fingers around the batteries easier. I then folded down the sides of the wristband over the fabric circuit and stitched the edges closed with the same normal thread. I left a small opening where the batteries are located, so I could have access to change them in the future.
Now turn the wristband right side out and let's take this bad boy for a run!
Step 6: Will It Actually Detect Hiding Pokemon?
I taped a small magnet to the bottom of one of the pokemon and stuck the plastic toy near the side of the wristband where the reed switch was located. Sure enough, the LED started blinking and the motor started humming and vibrating! Obviously, taping the magnets is not a long-term solution and definitely not for little kids who like to eat magnets, but for the testing phase it was the quick and dirty choice. In the future, I could drill shallow holes into the plastic toys and glue the magnets in place.
In the meantime, I supervised my son while he played with the pokemon and we hid the pokemon under a big cloth to see if he could find it with the bracelet. Wild pokemon watch out! We can find where you are hiding!