Step 1: The Tree
Step 2: Parts for Motion Sensor Lights
2. PIR Sensor
3. Raspberry Pi (any simple board like Arduino can also be used)
Step 3: Logic and Circut
Take input with Rpi , use simple if else logic to switch on and of the lights.
Sensors position and alignment can increase range upto 10 feet.
And you are ready with your power saving easy to make Christmas Tree