December 05, 2021 by Pedro Barrio
Christmas tree with addressable Led Strip and arduino
The tree decoration is made by my mother, I should tell her to share and make some Instructables.
Since there are other similar projects Christmas Lights Arduino and WS2811, Arduino Xmass tree I find them too complicated for newbies. So I decided to publish this simple and costless project, that you can try before facing more complicated ones, with even Bluetooth control and vu-meter.
Check the video
My family enjoyed designing the patterns, and I enjoyed coding them. I hope that you also enjoy it.
The tree decoration is made by my mother, I should tell her to share.
This are the materials I used:
Drill, drill bit. Glue gun. Soldering iron. Scissors.
It is connected to GND because we use the internal pull-up resistor in Arduino to avoid false signals. Then in code a 1 will be no pulsated, and 0 pulsated.
We will power everything through the USB connector. The led strip will be powered through the VIN pin for not overloading the voltage regulator.
There are many types of addressable LED strips. The ones based in WS281x are very common. This chip family makes the Pulse Width Modulation (PWM) for you for each color, based on the data received in the data input pin. It uses the first block of data with every color and pushes the rest of the data flow to the next chip trough the data out pin. Fortunately, there are Arduino libraries that make all this work transparent for you.
Since the WS2811 LED strip needs a 5V data input we choose an Arduino with 5V logic. A 3.3V one could also be used, but we should make some sort of logic level adaptation. If not, it could work but a little voltage drop could drive to incorrect data or no data at all arriving at the LED strip.
Simpler microcontrollers as ATtiny85 could be used if you want to cut more the cost. Since we only need 1 output and one input. Depending on the versions the flashing is more difficult if it does not have a USB port.
One with a long button will suit better to go through the case, then you can actuate it without a pencil.
It is connected to GND because we use the internal pull-up resistor in Arduino to avoid false signals. Then in code a 1 will be no pulsated, and 0 pulsated.
A hole for accessing the switch button. Machine hole for the USB connector. Cable output for the LED strip. In the cover mechanize it till the border in order to remove the cover.
I used a Candy box as the enclosure for the electronics. Use or even 3dPrint one that has enough space.
Just drill it with a Dremel multi-tool. I used a 3mm drill bit for:
Finally, connect all the connectors.
For wiring, we will need a soldering iron. If you are a novice check this soldering tutorial.
Tips from my own experience.
Wire the button to input D5 and GND.
The one I used has four pins. They are internally connected by pairs, check before with tester (or a led with a battery) which ones are opened.
Solder at one end a male connector for the led strip. You can use the one in the LED strip, that we will not use.
The colors I used are.
At Arduino Side
The LED Strip has two three-pin connectors, the input one is the female one. There are red and white cables with no connector that should be insulated with insulating tape or a heat shrink tube to avoid a short circuit.
Just solder pre-tinned cables in soldering pads,
Finally, connect all the connectors.
CablePut a cable tie to avoid that if eventually there is a pull, The soldering is not damaged.
Button To fix the button I used a glue pistol, put a generous amount and be careful not to glue the button mechanism. I had to do twice since the first time there was so little glue that when we pressed the button it glued off.
MicrocontrollerIt is not fixed.
CablePut a cable tie to avoid that if eventually there is a pull, The soldering is not damaged.
Software Tools and uploading
For the code, we used the FastLED library and Arduino IDE.
To install the library in Arduino IDE follow this guide Installing Additional Arduino Libraries Put in the search box FastLED
To upload to Arduino nano follow this guide. Getting Started with the Arduino Nano
Just press the button to change the current animation mode.
There is also a multifile class version that you can try.
