Have you been wanting to change things up this holiday season? Tired of the same old decorations you put up year after year? Why not add an unexpected element to your tree by controlling your lights from your smartphone? It may sound complicated, but you can do it yourself! Check out this guide to controlling your tree lights with your smartphone.


There are a few materials you will need, including an Android device. You will also need the Arduino UNO R3, a Bluetooth Serial Adaptor, a 5v Relay Shield and jumper wires for the Arduino.

Steps To Creating The App

  1. First, you will need to create an app on App Inventor. Don’t worry, it is a lot easier than it sounds!
  2. Make each button send a different “byte” in the system.
  3. Use a simple bluetooth editor app to locate the module’s address. Once you have it, enter the address into the block editor.
  4. Make the code. You can find a sample code here.
  5. You also have the option of using a pre-made app.

Setting Everything Up

Hooking everything up is rather simple. Hook the Bluetooth Module and the Arduino up using the 3.3v and GND. Also, make sure the TX from the module is hooked up to the RX on the Arduino and vice versa. Then, the four pins that you used in the code will need to be attached to the relay. At this point, you are finished hooking all the components up.

The next step is to test things out to make sure they are working the way you want them to. It is recommended that you do this with one string of lights and not your entire tree. Once you have it working the way you want it to, hook up the relays where you hooked up the lights. Make sure the curved lines on the front of the relays are facing each other. They should make a semi-circle. Then you need to hook the GND and hot wires from the outlet to the two lines that are not facing each other. If you want to make this permanent, you will need to follow this step for the assembly. Then you can set everything up and be ready for automated Christmas lights from your phone!

At LifeLine Repairs in Dunwoody, we are here for you whenever your device stops working the way it should. Whether you’re dealing with something simple like a shattered screen or a more serious issue like inability to connect to wi-fi or send and receive messages and calls, our repair technicians are here to get your device back to working order so you can get back to doing the things you love, like creating apps to automate your Christmas tree!