Key benefits Quick access to essential power rails: 5V, 3.3V and GND are exposed via dedicated pins, making extended experiments and custom wiring straightforward. Flexible clock options: The board uses an external crystal oscillator at 22.1184 MHz, and you can choose to run the microcontroller with its internal oscillator or an external oscillator as needed. Versatile power delivery: Power the core board via USB, an external 5V supply, or through the JTAG port using a downloader, giving you multiple sourcing options for different setups. Easy IO accessibility: All microcontroller IO pins are routed to two labeled rows of pins on the core board for clear identification and convenient connections. What you get and how it works Clock and timing: External crystal oscillator frequency is 22.1184 MHz. The design supports both using the internal oscillator of the microcontroller or using an external oscillator. Power options: USB power, external 5V supply, or downloaderenabled power through the JTAG port, enabling flexible testing and development workflows. Pinout and layout: All MCU IO pins are brought out to two rows of pins on the core board and are clearly marked for quick wiring and measurement. Attributes and compatibility Function: Core board for microcontroller projects with exposed power rails, flexible clocking, and accessible IO. Compatibility: Supports use with the microcontroller's internal oscillator or an external oscillator, with external crystal at 22.1184 MHz. Pin accessibility: Two labeled rows of IO pins on the core board for straightforward connection and prototyping. Size and layout: Tworow pinout arrangement provides compact, organized access to all MCU IO pins. Use scenarios Rapid prototyping and hardware development: Build and test microcontrollerbased prototypes that require easy access to 5V, 3.3V, GND, and IO pins, while choosing between internal and external clock sources. Educational labs and demonstrations: Teach clock configuration, power management, and GPIO wiring in a controlled, handson environment with clearly labeled pins. Embedded system testing and sensor interfacing: Set up hardwareintheloop experiments or sensor interfaces using the exposed IO pins and flexible power/clock options for reliable measurements. Notes The description maintains the original core board's specifications and functions: exposed 5V, 3.3V and GND pins, external crystal oscillator at 22.1184 MHz with option to use internal oscillator, multiple power options including JTAG downloader, and all MCU IO pins routed to two labeled pin rows.