Build a Minimalist BCD Wristwatch
The Qron0b project offers a sleek, low-power wristwatch design using an ATtiny microcontroller. This minimalist watch displays time in Binary Coded Decimal (BCD) format, focusing on efficiency and simplicity. Detailed schematics and code are provided, making it perfect for DIY electronics enthusiasts.
Read the build on hackaday.com: Build a Minimalist BCD WristwatchFeatured in TinkerNews Issue 3 ·
More Arduino builds
32 buildsHow an ESP32-S3 Renders N64-Style Megatextures
A custom software renderer lets an ESP32-S3 move through a textured 3D scene without a dedicated GPU. The project fits its megatexture data into 16 MB of PSRAM by using 8-bit indexed color, showing how mipmaps, compression, and careful memory choices support console-style graphics on small hardware.
Read the build on hackaday.com: How an ESP32-S3 Renders N64-Style MegatexturesAn Offline Arduino Agent That Understands Plain English
Type a plain-English instruction into an Arduino App Lab project, and a local language model on the UNO Q can direct connected hardware. This hands-on build combines Modulino sensors and outputs, showing how behavior can change through new sentences rather than firmware changes, without internet access or API keys.
Read the build on projecthub.arduino.cc: An Offline Arduino Agent That Understands Plain EnglishArduino Two-Axis Level With Zero Reference
A bubble level can check one surface, but this handheld Arduino tool can compare two. An ADXL345 feeds gravity readings to a Nano, which shows pitch and roll on an OLED. Press ZERO on one bracket, then match that stored angle on another—even when both are intentionally sloped.
Read the build on learniot.in: Arduino Two-Axis Level With Zero ReferenceAdd 16 I/O Pins with a PCF8575
A small PCF8575 module gives Arduino, ESP8266, or ESP32 projects 16 extra digital lines through just SDA and SCL. This hands-on setup uses LEDs and buttons to test the connection, while a library handles the I2C details and leaves the host board’s built-in pins available.
Read the build on mischianti.org: Add 16 I/O Pins with a PCF8575Build an Arduino/ESP32 OBD2 K-Line Tool
Older cars often speak K-Line instead of CAN. This Arduino/ESP32 library offers a practical starting point for connecting to those ECUs, provided you add a proper protected transceiver. The repository’s examples and source should confirm supported protocols, timing, wiring, and diagnostic commands before any vehicle connection.
Read the build on github.com: Build an Arduino/ESP32 OBD2 K-Line ToolBoatOpenIO v2: Modular Marine Gateway Main Board
BoatOpenIO v2 handles signal routing inside a four-board boat gateway. A 16:1 multiplexer sends selected analog inputs to one ADS1115 converter, while an MPU6050 watches for impacts. Socketed parts and swappable modules make repairs easier, but the board needs companion hardware before it can run.
Read the build on pcbway.com: BoatOpenIO v2: Modular Marine Gateway Main Board