Key features Power rails exposed: 5V, 3.3V and GND are provided via pins, enabling convenient extended experiments and easy wiring. Full IO access: All microcontroller IO pins are routed to two rows of header pins on the core board and are clearly labeled for quick identification and prototyping. Flexible power options: The core board can be powered via a USB power supply, an external 5V power supply, or a downloader, with power supplied through the JTAG port. Clock options and timing: The board uses a 22.1184 MHz external crystal oscillator. Users may also operate with the microcontroller's internal oscillator or switch to the external oscillator as needed. Use scenarios Laboratory prototyping and experimentation Connect sensors, actuators, and modules to the exposed 5V, 3.3V, and GND rails and the labeled IO pins to rapidly build and test ideas in a controlled lab environment. Firmware development and debugging Use the tworow, labeled IO header for straightforward wiring of peripherals during development. Power can be supplied via USB, external 5V, or downloader, and the clock source can be chosen between the internal and external oscillators to suit timing requirements. Education and handson learning The clearly marked IO pins and accessible power rails simplify teaching microcontroller concepts, allowing students to configure circuits quickly and observe results with minimal setup.