Cardiovascular diseases have dangerous consequences, even leading to death. To avoid such outcomes, early detection of cardiovascular diseases is necessary. Electrocardiography (ECG) is a medical device used for diagnosing cardiovascular diseases, which has been in use since 1901. By monitoring the disease through an electrocardiogram graph and the frequency of heartbeats, an electrocardiograph can be utilized for early detection in patients with cardiovascular diseases. The portable ECG design incorporates a voltage regulator circuit to measure voltage, XTAL to generate a stable frequency, PIC18F14K50 microcontroller as the central processing unit for the entire workflow of the portable ECG, a buzzer, an AD8232 sensor that captures electrical signals from the human body, an LCD screen, and programming. Additionally, the portable ECG circuit is supported by software such as Altium Designer, MPLAB X IDE v5.30, Nextion Editor, Autodesk Inventor Professional 2022, and Ultimaker Cura. In this project, we made a prototype of ECG using PIC18F14K50 microcontroller and the AD8232 sensor. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.