I had an idea to build an egg shaped night light that plays a melody when you move close to it.
This is the proof of concept with an Arduino Uno to test the idea. The light comes from an LED ring with 24 LEDs, the color of each LED can be set separately. To sense if anything comes close to the light a reflective infrared sensor is used. For playing a melody there is an MP3 player with amplifier to drive a small speaker.
Then it was time to print an eggshell to cover the LED ring. It took a couple of tries to get the right wall thickness to diffuse the light of the LEDs.
It was a challenge to close the top of the egg because of the thin wall and increasing overhang. reducing the layer height of the top layers and applying 100% infill for the top millimeter solved this issue.
Because I wanted the electronics to fit inside the diameter of the LED ring, the Arduino Uno microcontroller had to be replaced by a smaller board. I went for an ESP32 to make it easy to connect the night light to home automation in the future.
All the electronics are mounted on a prototyping PCB and placed in a the base. Note that the Wi-Fi antenna in the middle is not in use at this moment.
As a finishing touch some twigs are placed around the egg, The green plastic is painted so it doesn’t show trough the holes between twigs.
The night light is powered by a 5V micro USB phone charger. by default it glows in a warm white color. The egg will shine brighter if you move closer. When an object is detected at a distance around 10 cm from the egg, it will play a melody and cycle through colors before returning to the dim white light again.
