STM32-Based Heart Rate Variability Detection

Real-time monitoring of psychological stress is critical to maintaining physical and mental health. Although traditional ECG methods can provide accurate stress assessment, their complexity and high cost limit daily use. To address this issue, this paper designs a heart rate monitoring system based on the STM32F103C8T6 microcontroller, which provides an easy and cost-effective solution for stress monitoring. The system simplifies operations and reduces costs by detecting peak heartbeat signals to estimate interbeat interval (IBI) and analyse heart rate variability (HRV). The system uses the XD-58C PulseSensor for accuracy, including an OLED display for real-time data and a threshold range to ensure validity. Heart rate data can be uploaded to a PC platform for visualisation via serial communication, enabling users to track health trends. The system has been tested for ease of use, broad applicability, stable performance and high utility value to help individuals manage their mental health and as a preventive medicine tool to reduce the risk of disease and improve public health.