Through the "magic" of wireless power transfer, Rudolph's nose glows brightly when he is near his beloved, Clarice. Using the cloudBit and an IFTTT recipe, Rudolph's nose also glows brightly when there is snow in my area or when the Norad Santa tracker, @noradsanta tweets.
I made this project to meet several design requirements. Here were my goals:
- Test if I could embed and bake electronic components in polymer clay.
- Try wireless power transfer for the first time.
- Design a littleBits compatible, interactive toy that could work offline.
- Give the user option of using the toy as an internet connected device.
Repair Rudolph's broken tail.
Keep both deer functional as ornaments to hang on the tree.
- 1 x Rudolph ornament
- 1 x Clarice ornament
- Super Sculpey - use this to make the character's snowy ground, a new tail, and to encapsulate the electronics
- AND/OR make your own figures from scratch!
- 1 x rectifier diode
- 1 x 100 ohm resistor (brown, black, brown stripes)
- enamel coated magnet wire - around 26 gauge will do fine. I used 26 gauge for the secondary coil and 30 gauge for the primary coil; testing showed me that for this design 30 gauge worked for both coils. Both sizes can be found in Radio Shack part # 278-1345
- 1 x 2N2222 NPN transistor
- solder (use lead free for toys)
- 1 x hot glue stick
- tinfoil for baking
- white acrylic craft paint
- 1 x small red led
- 2 inches, small shrink wrap tubing
- 2 - 4 inches insulated wire as needed
- 5V regulated power source for testing (i.e. 1 x littleBits p1 power and 1 x 9V battery)
- 1 x littleBits USB power - for use with cloud
- 1 x littleBits button
- 1 x littleBits CloudBit
- 1 x male Bitsnap - purchase in a pack or as part of the littleBits HDK
- soldering iron
- helping hands
- breadboard(s) for testing
- wire cutter / stripper
- paint brush
- hot glue gun
- computer with internet access
- cookie sheet
Step 1: Wireless Power Transfer Circuits
If you are concerned about frying littleBits while testing the wireless power transfer coil, I recommend you build a 5V regulator circuit. For complete instructions on the 5V regulator circuit, including parts, visit my DIY littleBits 'ible, Step 1: POWER!.
Wrap 30 gauge wire 12 times around a 1.5 inch cylinder, leave about 1 inch out to twist, then continue around the cylinder 12 more times in the same direction. There should be two 3-inch leads and a center twist. Fasten the coil together temporarily with tape to prevent unraveling. Don't use hot glue, because it will liquify in the oven.
Breadboard these points for the PRIMARY COIL:
- collector of NPN transistor to the twist
- base of NPN transistor to a coil lead
- negative side of diode to other coil lead
- emitter of NPN transistor to 100 ohm resistor
- positive side of diode to + 5V (signal littleBits)
- other lead of 100 ohm resistor to - 5V (ground littleBits)
Wrap 26 gauge wire 24 times around a 1.5 inch cylinder, leaving two 3-inch leads. Tape or twist tie the coil together temporarily to prevent unraveling.
Breadboard these points for the SECONDARY COIL:
- each lead of the red led to each lead of the coil.
The orientation of the red led does not matter.
At this point you should be able to turn on the 5V. Bring the secondary coil over the primary coil to see if the red led lights. Check the transistor and your 5V regulator for heat. If either is hot or if the red led on the power source goes dim, turn off quickly, and check your connections for a short.
If everything is working as you think it should, solder it up! Make sure to slide two segments of shrink wrap on the leads of the secondary coil to prevent the led leads making contact. Once they are soldered, slide the shrink wrap in place and heat shrink it with a flame. Extend the positive and negative points from the primary coil (see steps 5 & 6 above) with insulated wire.
My source of information for how to build these coils came from YouTube video "Improved - Simple Wireless Electricity System", which slider2732 published under Creative Commons attribution license. He has several videos on this topic.
Step 2: Baking Components in Super Sculpey
Condition the clay until it is soft. The intent is to hide electronics while maintaining an even footing for characters and a thin enough layer of clay between coils so that the coils get close enough together. It's ok if snow looks lumpy and messy. :)
Clarice's area / PRIMARY COIL
String the two insulated wires to the left. They can hang out an inch beyond Clarice's snow platform. Fit the bitsnap into the snow, but don't solder it in place yet, and don't bake it with the clay.
Rudolph's footing / SECONDARY COIL
I left this coil exposed in a channel on the bottom. That's because I want to be able to explain it to other people. Whatever you decide, make sure you continually test functioning every step along the way. The farther apart the coils are, the dimmer the red led will be. I shoved Rudolph's feet into his footing, but did not bake him with it. After it cooled, I hot glued his feet to the footprints.
Once you are finished sculpting, bake according to manufacturer's instructions: 275 degrees F for 15 minutes per 1/4 inch. To minimize baking time and risk of melting the transistor, keep the clay up to 1/4 inch thick. Once cool, hot glue Rudolph to his footing, his coil to his footing channel, and his led to his nose (I cut off his original nose with wire cutters). Hide wires up the side of his body. Solder the signal and ground wires to a male bitsnap. Test with littleBits power and button. Paint the snow white.
Step 3: Add the Internet
Now that Rudolph's nose works with littleBits and in Clarice's area, we can add the internet.
Build this littleBits circuit:
USB power + button + CloudBit + Clarice & Rudolph
Use the button for testing CloudBit connectivity in cloud control.
Create recipes at www.IFTTT.com . Here is one I already made:
There are lots of channels on IFTTT. You could even make a recipe that makes Rudolph's nose glow when there is snow! Try making a recipe using the Weather Channel - IF current conditions in your area = snow THEN set CloudBit output to 100% for 30 seconds.
If you are new to building with electronics, replace the Clarice & Rudolph wireless transfer circuits with a littleBits bright or long led. Design a Rudolph face on the back of a paper plate with a translucent red nose. Put the led behind the nose, and follow the rest of the instructions on this step to get your Rudolph connected to the internet!