How many times have you found yourself looking at your cake decorations, wondering how many pearls are left in the box? Have you ever tried to count how many mustard, basil or pepper plants you can grow with the seeds you have in stock? And what about the urge to know the exact number of millimeter stainless steel balls you recently purchased at your favorite DIY store?
For this purpose, some scrap cardboard, a strip of LEDs, and a Raspberry Pi Zero with its tiny chamber might help satisfy your mathematical desire to enumerate these tiny objects.
In a recent article on Instructables, we detailed the eye-opening experience with all the construction details of a compact, battery-powered, easy-to-use, and affordable mini LED table (MTL). In addition to the hardware, an open source software based on OpenCv is also strengthened for the acquisition and simple processing of the images of the objects on the MTL for possible applications.

The main features of the Mini LED Table are as follows:

1. Easy-to-Build: The Mini LED Table is a DIY project that can be easily constructed using readily available materials. The instructions provided in this blog will guide you through the building process.
2. Compact and Portable: The device is designed to be compact and portable, allowing you to use it anywhere you need. It is battery-powered, making it even more convenient to use.
3. LED Lighting: The Mini LED Table utilizes a 12V LED strip for uniform lighting. The strip is divided into six segments, each consisting of four units with three LEDs. The LEDs are placed at the bottom of the device to provide adequate illumination.
4. LED Dimmer and Power Supply Plug: The device includes a PWM Speed Controller 3V-35V LED Dimmer with a switch for adjusting the brightness of the LEDs. It also features a 12V DC Male and Female Power Connector Adapter for easy power supply connection.
5. Raspberry Pi Zero with Camera: The Mini LED Table incorporates a Raspberry Pi Zero W and a Raspberry Pi Camera V1.2 for computer vision capabilities. The camera is modified to adjust the focus distance, allowing it to capture close-up images of small objects.
6. Support Bridge and Tray: The device includes a support bridge made of cardboard and 3D-printed parts. The bridge holds the Raspberry Pi and the camera, allowing for precise positioning. A tray is also provided to hold the objects being counted, with additional features like a plastic sheet and a black paper frame to improve object visibility.
7. Computer Vision Software: The Mini LED Table is equipped with computer vision software developed using Tk-Python and the OpenCV library. The software provides an interface for controlling the camera and offers features such as continuous monitoring, adjusting the field of view, adjusting image parameters, capturing snapshots, and object counting.
8. Educational and Customizable: The Mini LED Table project is not only practical but also serves as an educational tool. It can be used to teach concepts of construction, electronics, optics, and programming. The provided software can be further enhanced to include additional image-processing features for specific applications.

In conclusion, the Mini LED Table is a compact, affordable, and versatile device that combines LED lighting, computer vision, and easy-to-use software. Whether you want to count small objects or explore the world of DIY electronics, this project offers a fun and educational experience.

To see the detailed instructions and images, please refer to the original instructables link:

https://www.instructables.com/Introducing-the-Mini-LED-Table-Compact-Affordable-/

Give it a try and enjoy the process of building your own Mini LED Table!