Info About The LEDs
Before we begin there is some information about the LEDs which would be handy to know before building the poi.
The LEDs will arrive with wires and a connector already soldered in place. Ignore this, in fact you should remove it straight away. The wires are almost never soldered on correctly, according to the colours, so we will be using our own wires for this project.
The LEDs strips are made in short lengths and soldered together in the factory. The LEDs are spaced further apart at the join than normal which you may find annoying (I'll talk more about this later).
The arrow on the LED strip indicates the data flow direction (more on this later).
Sticking The LEDs To The Plastic Strip
Find two section of 55 LEDs without a large soldered joint.
Have a look at the next section if you need to cut out a manufacturers join.
Make a cut at the start of the strip so that all of the solder pads are intact to the left of the LED (this will be the start of the strip). Shown in the top picture.
Make a cut to the right of the 55th LED as close to the LED as possible (this will be the end of the strip). Shown in the bottom picture.
Peel the sticky backing off the strip and stick the LEDs to the middle of the plastic. Start at the end of the strip making sure it's flush with the end of the plastic.
Flip the plastic over and stick the other LED strip in place.
How To Join The LED strip (Skip This Step If Not Required)
If you find the the gap between the LEDs at a join made by the manufacturer to be too much you will have to chop out the join and reconnect the LED strip.
We will remove the join and the LEDs either side, so cut as close to the LEDs both sides of the join as possible (leaving the solder pads with the two longer bits of the LED strip you just cut).
When we solder the strip back together the two sections will overlap at the solder joints so decide which strip will be on the bottom, flip it over and peel about 1cm of the sticky tape off.
Add some solder to each of the pads at the end of the strip
Stick the non soldered strip in place and stick the soldered strip in place with the solder we just added over the pads of the other strip.
Add heat the top solder pads making sure a connection is made between both the strips.
Attaching Wires To The LEDs
Make sure the arrow points to the right and solder the wires in place, red (power) on top, then green (clock), yellow (data), and finally black (ground) on the bottom. Flip over the strip and repeat.
Now cut the wires short and match up the colours from either side (red with red and so on), this will cause some criss crossing.
Finally, solder on a longer piece of wire for later and cover the join with heat shrink (don't forget to shrink it).
Attaching Wires For The Battery
Cut lengths of red and black wire (about 400mm).
Use hot glue to stick the black wire to the top of the LED strip, in line with the black wire already at the top.
Flip over the LED strip and do the same with the red battery wire.
Soldering On The Battery Charger
Make sure the LED strip has the arrows pointing to the right and the red battery wire on top.
Cut the red and black battery wires to length and strip the ends. You want the battery charger to be as close as possible to the LEDs.
Solder on the battery charger (red wire in B+ and black wire in B-).
Solder a length of red wire to + and Out +, a length of black wire to - and finally the black LED wire to -. It may seem strange doing it this way round but this way makes our lives easier later.
Soldering The Switch In Place
Solder a piece of red wire between the middle pin of the switch and Out -.
Solder the red LED power wire and a length of different piece of red wire to another pin on the switch (don't forget to add heat shrink before soldering the red LED wire in place).
Shrink the heat shrink.
Adding The Teensy Micro Controller
Before adding the Teensy, make sure to cut between the two pads providing USB power to the board (check the pin assignment guide that came with your Teensy for more information or click here). You want to make sure the pads are definitely separated as it stops the Teensy turning on while the poi are charging.
Solder Out + on the battery charger to Vin on the Teensy and out - to GND.
Finally, solder the yellow data wire to pin 2 and the green clock wire to pin 3.
Have a look at the schematic included in the downloadable files for more information
Adding The Battery
Add some solder to the positive and negative terminals of the battery (it will take a while before the solder sticks but be careful not to overheat the battery, bad things could happen).
Cut the red wire to length, tin the end and solder it to the positive terminal of the battery.
Repeat the same step for the negative terminal of the battery.
Adding The Assembly To The Tube
First you will need to seal one end of the tube using any method you like (I would recommend Sugru but I didn't have any at the time). I ended up using hot glue and sealed it in layers by slowly adding glue and letting it dry.
Once the end has been sealed and dried, slide the assembly in to the tube and mark a place for two holes. We will thread some string through these holes and tie a knot in the end so you want to make sure there won't be anything like the switch or the wires in the way.
Drill the holes, place the assembly back inside the tube, thread the string through the holes and tie a knot in the ends.
Seal up the end of the tube, making sure the switch and the controller are flush with the end of the tube (I recommend using hot glue with the tube on a flat surface like a table for this part, but add a layer and let it cool before adding another, you don't want to heat up the Teensy too much as it could be damaged).
Now its time to turn on your poi. If everything went well an LED on the Teensy should start blinking (this is because the Teensy comes with a default blinking program).
Switch the poi off and connect a USB cable to the port on the poi, the charging light on the battery charging board should turn on.
At this stage the Teensy shouldn't power on (because we cut the circuit providing power to the Teensy from the usb port). If yours does turn on you didn't cut between the pads well enough. While this isn't a problem you may want to go back and make sure the pads are separate to prevent the Teensy turning on when charging the poi.
Finally, you'll want to find some nice handles to use. I went with a Flowleash from Flow Toys.