DIY Phosphorescence Detector and Arduino Nano Controlled Mini Plotter

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DIY Phosphorescence Detector

This is a device capable of detecting weak phosphorescence phenomena.

The author wanted to explore whether there are some luminescent materials in our daily life that are difficult to detect with the naked eye. These materials may emit light briefly after exposure to ultraviolet light, but the light may be too weak or last too short a time for us to observe directly.

To detect this weak luminescence phenomenon, the researcher designed a special device:

1. Using a small metal can as a testing chamber
2. Installing 4 ultraviolet LED lights and 1 photodiode on the can lid
3. The photodiode is connected to a complex circuit that can amplify and measure extremely weak light signals
4. Using a microcontroller to control the entire system and collect data

Working Principle

1. Place the sample in the sealed metal can
2. Illuminate the sample with ultraviolet LEDs for a few seconds
3. Quickly turn off the LEDs while measuring any weak light that the sample may emit with the photodiode
4. The circuit amplifies this weak signal and converts it into digital data
5. The microcontroller collects data and displays the results on an LCD screen

The author tested various everyday items and found some unexpected results:

1. Milk powder exhibited a fairly strong phosphorescence phenomenon
2. Gelatin also glows briefly
3. A regular natural ruby showed amazing phosphorescent properties
4. Animal proteins seem to produce phosphorescence more easily than plant-based materials

This project demonstrates how to use electronics and physics principles to explore the wonderful phenomena in daily life, showing us the microscopic world that cannot be perceived by the naked eye.

Source:<span>https://lcamtuf.substack.com/p/building-a-phosphorescence-detector</span>

DIY Portable PC Game Console

Tired of the handheld game consoles on the market, Marcin Plaza built a portable PC game console similar to the Nintendo DS, equipped with an ultra-wide screen. Unlike traditional controllers, Plaza designed a foldable game console that not only protects the screen but also hides the controller, solving the problem of controllers getting caught.

The core of the project is a second-hand Lenovo laptop purchased for just $50, which was successfully miniaturized by cleverly stacking the motherboard, battery, and other components. The decision to use a 12.7-inch ultra-wide screen, while unusual, perfectly matched the design of the device.

In the end, through a 3D printed shell and a custom circuit board, Plaza perfectly integrated all components to create a unique portable PC game console.

Source:<span>https://www.hackster.io/news/flipping-awesome-6fb4427c3666</span>

Arduino Nano Controlled Mini Plotter V2

This project introduces an affordable mini plotter V2, controlled by Arduino Nano and running GRBL firmware. The core components include a modified 28BYJ-48 stepper motor, servo motor, and 3D printed parts. These parts work together to achieve precise movement on two axes.

The project used waste materials, such as bicycle spokes and old LCD writing boards, combined with 3D printing technology to make the entire machine cost-effective, easy to assemble, and compact.

Source:<span>https://www.instructables.com/Mini-Plotter-V2/</span>

Sit Sensor – SitSense

Feeling like a turtle sitting at the desk every day, with neck stretched forward and back discomfort, the author designed SitSense, which monitors sitting posture using ESP32-S3 and IMU sensor (MPU6050). If the posture is incorrect, a buzzer will remind you to correct it; otherwise, the computer will automatically lock after 10 seconds. Want to unlock? Just sit up straight.

SitSense offers two versions:

• Simple Version: Quick and easy to use, based on preset baseline posture detection.
• Advanced Version: Uses a model trained with EdgeImpulse for higher posture detection accuracy.

In terms of hardware design, SitSense adopts a 3D printed shell and magnetic clip design, making it easy to attach to the body or wall.

Hope everyone can maintain good posture and protect their spine.

Source:<span>https://community.dfrobot.com/makelog-314930.html</span>

Retro “Floppy Disk”

This project is a practical and nostalgic “floppy disk”.

Through a microcontroller, this floppy disk can connect to a computer, triggering the save command by pressing the floppy disk.

Additionally, it has an auto-save feature that can automatically execute the save command at set intervals.

Source:<span>https://www.instructables.com/A-Beautiful-Retro-Floppy-Disk-Picture-Frame-With-a/</span>

Star Projection Lamp

Want to enjoy the romance of the vast starry sky at home? This 3D printed star projection lamp can meet your needs!

Using simple optical principles, this projection lamp can cast realistic stars on the ceiling, making you feel like you are under the starry sky at night.

The project highlights its portability and customizability; you can adjust the position and brightness of the stars according to your needs. The project uses 3D printing to create the star dome and base, combined with LED lights and lithium batteries, creating an easy-to-operate portable device.

Whether preparing a dreamlike starry night for children or creating a peaceful night for yourself, this DIY star projection lamp can easily achieve that.

Source:<span>https://www.instructables.com/3D-Printed-Star-Projector/</span>