I would like to share the last project I did and it is a Christmas lantern controlled by the microcontroller. This project was made for our Christmas party lantern making contest and successfully we won the very first spot. The main guideline was to build a lantern made from excess materials with minimal costs. The only things we bought here were the 20 light bulbs controlled by the microcontroller and their holders. Everything else then are just found from the excess storage area.
The project was a 5 ft tall lantern composed merely of junk wires, light bulbs and considerable amount of electronic components. The lantern was synchronized with monotone tunes. There were 5 different songs used and every song has different light sequences. The songs were arranged in this order: Winter Wonderland, Let it Snow, Rudolph the Red Nose Reindeer, We Wish You A Merry Christmas and Jingle bells.
Watch the video at the end of this post.
Here’s the final image of the lantern.
This is the Project composition.
Microcontroller – I used 2 PIC18F4620 (any lower/higher model of microcontrollers with at least 20 I/O pins might work as well) to control the light bulbs and the speaker.
NPN Transistors – I used 20 NPN transistors since there were 20 bulbs.
Resistors – these were used to limit the base current fed to NPN transistors.
Microcontroller Electronics Template – these were composed of the basic discrete components typically used to power the microcontroller.
Power Regulator Circuit – composed of the old school 3A rated rectifier diodes rectifying 20VAC transformer (tweaked) feeding signal to 12V and 5V regulator ICs with huge heatsinks with them.
Here is the image of the control circuit.
First, I used first to simulate the lights and sound but unfortunately they didn’t synchronize well so I just used Proteus to simulate the lights. I used roughly 20-25 patterns with varying speeds for the bulbs. I synchronized them by making the microcontroller that controls the bulbs send a specific signal to the microcontroller that controls the tune when the pattern is close to end. The music will not be play the song unless it receives the specific signal.
Here is an image of the simulation used to signify the bulbs.
The LED controller software utilized look up tables for easier data retrieving of different patterns. I also used logical operations to decrease the code size giving me more patterns to place. I was given only a week to build everything so I didn’t come up with so many patterns. Anyway I posted the code below for the people who is interested on building their own lanterns.
Download the code from here:
Check the lantern in action:
If you got questions just post it below.