Once your kit has arrived, you’ll need to solder it together. It’s quite simple but there are a few things you need to watch-out for, specifically: pay very careful attention to the orientation of the LEDs!
You can watch a video showing how to construct your tree here: http://youtu.be/N3r6LpCCm_s
Photos will follow, but here are brief instructions for the time being:
1) Solder the four 100Ω resistors in place – it doesn’t matter which way round they go but you may like to use the same orientation each time just for neatness.
2) Position the 6-pin connector at the bottom of the tree and initially solder just one pin. Check that the connector is straight and, when you are happy, solder the remaining pins.
3) Now for the 6 red LEDs. It is very important that you observe carefully which of the LED’s two wires is the longer one and insert it into the hole with a ‘+’ symbol next to it (the pad for the long wire is also square-shaped). Just to complicate matters, not all LEDs are required to be the same way round! For example, LED_2 is the opposite way up to LED_1.
4) The yellow LED is soldered at the top as LED_0. Again, it must be soldered with the long wire in the ‘+’ hole.
This is what you are aiming for:
When attaching the tree to your Raspberry Pi, it should connect to the GPIO pins furthest away from pin 1, i.e. pins 21-26 on the A/B and 35-40 on the A+/B+