Budget Party Light
A super cool, super cheap party light made from the classroom's existing projector and a two-axis mirror rig we designed.
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Background
Christmas was coming up, and our homeroom teacher suggested we throw a class Christmas party. The moment I heard that, I volunteered for the lighting crew. But when I went on Shopee to buy some party lights, the prices were way over budget, so I started thinking about other options.
Then I looked up and saw the projector on the ceiling, and it hit me: what if I put a mirror in front of the projector and bounced the image all around the room? That’d basically be an ultra-high-res party light. So I got right to work designing a projector party light.
Materials
- Arduino Uno
- Mirror
- 3D-printed parts
- 3-axis analog joystick
- SG90 servo motors
- nRF24L01+ wireless transceiver modules
- Bamboo chopsticks
How It Works
The transmitter reads the joystick position and sends it over the nRF24L01 module to the receiver, which drives the matching servo to rotate the mirror.
Reflections
I thought this project would be pretty easy, but it didn’t take long for the first problem to show up: for some reason, the nRF24L01 kept dropping the signal when I set the power to high. Luckily, after some testing, it turned out the low setting was enough to cover the whole classroom. Then we realized some of the party performances needed the projector, and our rig would block it. That had me stuck for a while, until it suddenly clicked: just rotate the mirror all the way up! Problem solved 😅.
By then it was already the day before the party. My classmates and I stayed after school to figure out how to mount it. In the end, we hot-glued the SG90s onto two sticks and zip-tied them to the projector. We thought we were done, ran one last test, and found out the SG90 was mounted backwards (an SG90 can only rotate 180°, and the plan was 90° each way, but now it couldn’t turn left at all and could turn a full 180° to the right 😭). We were out of time though, so we decided to just roll with it the next day.
At the party, we excitedly fired up the system… and five minutes later people complained it was too bright, so we had to turn it off. Plans don’t always survive reality, but it still became my very first project in high school, and I hope to build even better things from here.