The Qduino Mini is a compact, Arduino-compatible development board with built-in LiPo battery charging and a fuel gauge for monitoring battery level. Based on the ATmega32U4, it runs at 3.3V/8 MHz and measures just 2 × 3.8 cm — ideal for embedding in space-constrained projects.

The board charges via USB with automatic switching between USB and battery power, so you can program and charge simultaneously. Two RGB LEDs are included: one for charge/TX/RX status and one that is user-programmable. It is breadboard-compatible and 100% open source.

Key Features

• Built-In LiPo Charger – MCP73831 charges via USB with auto-switching circuit
• Battery Fuel Gauge – MAX17048 monitors battery level with Arduino library support
• Ultra Compact – 2 × 3.8 cm, 3.5 g
• Two RGB LEDs – Status LED (charge, TX, RX) plus a user-programmable LED
• Breadboard Compatible – Standard pin spacing for prototyping
• Arduino Compatible – Program via Arduino IDE with Qduino Mini board profile

Specifications

• Processor – ATmega32U4
• Flash – 32 KB
• SRAM – 2.5 KB
• EEPROM – 1 KB
• Operating Voltage – 3.3V @ 8 MHz
• Digital I/O – 26 (13 dedicated), 7 with PWM
• Analogue Channels – 12 (6 dedicated)
• Interfaces – SPI, I²C, UART
• Regulator – AP2112K 3.3V 600 mA

Ideal For

• Battery-powered wearable projects
• Quadcopters, drones, and high-altitude balloons
• Compact embedded electronics
• Portable data logging

Resources

• Quickstart Guide
• Graphical Datasheet (PDF)
• Hardware Design Files (GitHub)
• Arduino Board Profile (GitHub)
• Schematic (PDF)