Look at the board and enjoy the roundness. You can put it on your tree! Note that everything except the battery connector pushes through the front of the board
Start by soldering the switch: push it through the hole and
solder the legs.
Next solder the chip socket: after pushing it in, hold the
board down onto the table to keep it flat. Start with one
corner, then the opposite corner, and then all the other
pins. Easy.
Optional! If you want to add something to hold the badge off
your clothes you can add a capacitor t othe two pins in the
middle of the board. Do this by pushing it from the back
and soldering the front.
Now it's time for the battery casing. To solder this:
Tin the square pads on either side of the big round
pad. To do this, hold the iron to a pad and add
solder until there's a thin layer.
Place the casing over the pads (with the for the batter
facing the bottom) and touch the iron again the
parts above the tinned pads, add some solder.
Flip the board over.
Find the LEDs, you are nearly done!
Push the LEDs through from the front. They should
all be oriented with the long legs to the
left
Flip the board and solder the legs.
Snip them close to the board.
All the soldering is now done! Check everything looks good and slide the chip into the socket. The small dot should face the topmost corner of the hat.
Finally, slide the battery into the holder and watch the
lights. Press the button to start the sequence again.
Circuit
This circuit uses a technique called charlieplexing to control a
bunch of LEDs with a smaller bunch of pins. See my upcoming
blog post for more info!
