These candles flicker like a real candles and can be activated with an actual flame

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

Add spoken feedback to any Arduino project by sending text and sensor values to a TinyTTS module over UART — no cloud, no audio files.

This is a small (17.9 mm x 10.3 mm) breakout board for PixArt's PAA3905 optical flow sensor. It provides X-Y velocity at 126 Hz via Optical Flow and 35 x 35 pixel video camera at 18 Hz. There is a well-commented Arduino sketch showing how to use the device for navigation and frame grabbing. The frame grab rate is significantly improved over its predecessor, making for a practical low-resolution still imaging and video camera capability. Power usage is a modest 3.5 mA and the sensor can move in and out of shutdown mode quickly allowing flexible power management. The light level adjustment is automatic (although can still be done manually), streamlining sensor management. The sensor is smaller than its predecessors, with fewer pins making design and assembly easier. Light level sensitivity extends down to 5 lux. The frame grab occurs at a crisp ~15 Hz (56 milliseconds to complete), allowing low-resolution video imaging using the infrared-sensitive sensor element. Open source design!

A cute tiny infrared thermometer with -70 to 380 °C temperature range

Project #28 – Sensors – Tilt Switch – Mk28

Project #15: Environment - AHT20 Temperature and Humidity - Mk35

Project #15: Environment - Buzzer - Mk36

Project #15: Environment - SD Card Module - Mk37

The project successfully demonstrates the integration of graphical user interfaces, I2C sensors, and the ESP32-S3 microcontroller into a compact avionics instrument simulator.

In this tutorial, I am going to talk about the PC817 Optocoupler which is one of the most common and inexpensive 4-pin optocouplers.

A circuit that suits for cold areas, to prevent the frost.

Project #28 – Sensors – PIR – Mk23

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.

A low-cost MEMS gyrocompass measures Earth s rotation to determine true north and latitude, independent of magnetic fields.