Renal hydrosodic regulation is a complex process involving a coordinated interaction between hormonal and cellular mechanisms. These mechanisms are essential for maintaining systemic homeostasis. Despite its physiological importance, this subject remains challenging for students to master, as conventional teaching approaches often struggle to translate its complexity into accessible learning experiences. To address this limitation, we developed KidneyLab 2.0, an Arduino-based teaching platform that integrates real-time simulations with experimental practice. The system integrates conductivity and ultrasonic sensors with a programmable microcontroller, allowing measurement of sodium concentration, monitoring of fluid levels, and reproduction of regulatory responses. Students first establish calibration curves to determine sodium content in unknown solutions, then simulate normal and pathological conditions, including hyponatremia, hypernatremia, and renal failure. These tasks provide direct insight into homeostatic mechanisms such as antidiuretic hormone activity and the renin–angiotensin–aldosterone system. The KidneyLab 2.0 initiative employs a systematic approach to translate theoretical principles into observable data, thereby enhancing the comprehension of renal physiology and promoting the development of problem-solving skills. The system’s modular configuration facilitates its extension to other domains, such as acid–base balance or glomerular dynamics. This innovation highlights the pedagogical value of low-cost digital technologies in medical education and their capacity to bridge the gap between conceptual knowledge and practical application.