This is a simple visually interesting toy for describing fluid dynamics.

Project #15: Environment – Crowtail Moisture Sensor – Mk22

SAMD21G18A Sensor Board with Color Oled

Project #28 – Sensors – Water Sensor – Mk26

This innovative project is a robotic lion model made entirely using e-waste and recycled materials. It uses an ultrasonic sensor to detect nearby objects (within 2 meters), responds with a realistic roaring sound, and wagging tail movement through a servo motor. Designed to encourage sustainability and creative reuse of discarded electronics, this project blends environmental awareness with practical electronics and coding skills, making it perfect for student learning and STEM outreach.

These miniature metal detectors cannot boast of any great sensitivity, but it would still be good to make them for any enthusiast in this field, especially because of the opportunity to study in detail the way such devices work.

A small dot moves on the screen based on the K10’s accelerometer readings, creating a tilt-controlled interface.

Project #15: Environment – RTC – Mk26

Minimalistic board that allows you to quickly and easily utilize a silicon photomultiplier (SiPM) within your other projects. Supports a range of input voltages, has a digital (TTL) pulse output for the registered counts and a direct output for the SiPM pulses for easy expansion.

Electricity meter with touchscreen and remote access.

The OBP40 is an open, cost-effective marine multifunction display, ideal for DIY boat projects and sensor visualization. It's based on the CrowPanel 4.2 with an e-paper display and an ESP32-S3, 8 MB Flash, and 8 MB PSRAM. The system displays numeric and graphical pages with user-selectable values ​​and trends and is operated via buttons. Power is supplied via 5V USB-C. A LiPo battery pack with deep discharge protection and a magnetic dock enables mobile operation. Data communication includes NMEA2000, NMEA0183, 2.4 GHz Wi-Fi, and I2C/1Wire via an expansion port – perfect for integration with onboard electronics and sensors. The open-source firmware is customizable and can be deployed via Wi-Fi or USB. Comprehensive documentation, Telegram support, and wiring diagrams facilitate replication. This makes the OBP40 a flexible, expandable display module for boat data visualization and DIY marine electronics.

Project #30 - UNIHIKER - MEMS - Mk07

Measure Earth’s rotation using two MEMS gyros, a Pi Pico, and smart signal processing—precision within 2% of the true value!

This guide describes how to build the XIAO METER demo board, designed to easily test a wide range of sensors using the XIAO SAMD21 by Seeed Studio, the smallest member of the Seeeduino family. The module measures only 20×17.5×3.5mm, and features a Cortex-M0 microcontroller, 11 I/O pins, and supports UART, I2C, and SPI communication. It is fully compatible with the Arduino IDE.

Project #28 – Sensors – MQ-135 Gas Sensor – Mk22

The Self-Balancing Robot is a two-wheeled mobile robot that uses control theory and sensor feedback to maintain its balance, similar to how humans balance on two legs. It demonstrates fundamental principles of robotics, mechatronics, and control engineering. This project is designed as an educational tool to learn about sensors, actuators, control algorithms, and embedded systems.