Accurate measurement of joint angles is critical in the diagnosis, monitoring, and treatment of musculoskeletal disorders. In this study, we focus on developing a reliable system for measuring the elbow joint angle in a clinical setting, utilizing an exoskeletal linkage-based approach. To achieve this, we design and implement a novel goniometer that combines mechanical simplicity with high measurement accuracy. The device is built around a modern AVR microcontroller platform, ensuring ease of manufacturing, low power consumption, and real-time performance. One of the key innovations of this work lies in the ergonomic and wearable physical design, which enhances user comfort and minimizes interference with natural joint movement. The proposed system is lightweight, compact, and can be worn for extended periods without discomfort, making it particularly suitable for patient use in both clinical and ambulatory environments. Furthermore, the goniometer supports real-time data acquisition and communication via a USB interface, allowing for seamless integration with external monitoring or data logging systems. This feature facilitates mobility during experimental procedures while maintaining continuous tracking of joint kinematics. Overall, the proposed solution presents a practical and efficient tool for clinicians and researchers seeking accurate and wearable joint monitoring systems.