Assembly Instructions

The XMAS comes as a kit and must be assembled before use. Don't worry, it only contains a few parts and is suitable to beginners to soldering.

If you have never soldered before, you might want to review a beginners guide to soldering. We recommendthis one.


To assemble this kit, you will need:

  • A soldering iron
  • Solder
  • A wire cutter (a diagonal type that allows you to cut the wires as close to the soldering points as possible is best)
  • Helping hands or clips to hold the PCB in place when soldering (a vise will also work)
  • Protective glasses


  • Pinchers
  • A multimeter
  • Desoldering wick
  • Solder sucker

See the equipment page for more details.

Step 1: Resistors

Find the four resistors and bend the legs 90 degrees. Now, insert them into the four resistor footprints on the PCB. Resistors are not polarized and may go in any way.


You might want to use pinchers to pull the legs of the resistors in place so that they all lie flat against the PCB. Bend the legs of each resistor out so that the resistors stay in place, then turn the PCB over.


Now, carefully solder each of the resistor legs. Once you are done, clip off each of the legs with a wire cutter. Be careful, the legs may fly out when you clip them (it is best to wear eye protection to avoid accidents).


Step 2: LEDs

Next, let us place the four red LEDs. LEDs are polarized and must go in the right way, or they will not light up. The short leg should go to the point nearest the tip of each point of the star, and the long leg should point towards the resistor.


Turn the board over and solder the legs in place:


Now cut off the excess part of the legs like in the previous step.

Step 3: Battery holder pad

Before placing the battery holder, melt a small amount of solder against the squre pad in the middle of the battery holder footprint.

Step 4: Battery holder

Next, we will place the battery holder. It fits in one direction to match the drawing on the PCB board. It may fall out when you turn it over to solder it. One easy solution is to use a bit of masking tape to hold it in place.

Turn the board over and solder one leg first: Make sure orientation is ok and the battery holder sits neatly against the board. If not, reapply heat and adjust the position. Be careful, since the battery holder will get hot very quickly.

Once you are happy with orientation, solder the other leg. Wait a little bit before proceeding to step 4 to allow everything to cool down.


Step 5: Microcontroller

The final step is to place the microcontroller. It is the black 8-legged chip.

Before placing it, it may be neccesary to bend the legs of the processor inwards slightly to make it fit in the board. Press each side gently against a flat surface like so:


You will notice that there is a small dot in the upper left side of the microcontroller: It must be placed so that the dot is in the same side as the half-circle on the PCB.

The component may fall out when you turn the board over to solder. You may use a small piece of masking tape or similar to hold it in place.Solder only one leg first, then check that the orientation of the component is correct. If not, re-apply heat and adjust as neccesary. Once you are happy with the orientation, solder the remaining legs.


Step 6: Battery

Finally, let's insert the battery.

Turn the board over, you should see the LEDs blinking.

CONGRATULATIONS! You have assembled the XMAS decoration.