Cardiovascular diseases are a group of diseases of the heart and blood vessels that kill the most in the world today. For the identification of these diseases, the electrocardiography exam is one of the most used complementary medical exams. And cardiac monitoring in critically ill patients is imperative. Given the criticality of this equipment, it is necessary to periodically evaluate its operation, using standard patient simulators. This work aims to develop a low-cost electrocardiogram (ECG) signal simulator prototype. The prototype has an Arduino Due board for generating the standard signals, and a shield developed to allow the calibration of the 12 leads present in an electrocardiograph, at the same time. The parameters of the projected signals were based on the manual of a commercial ECG simulator. Bench tests were performed to verify the accuracy and precision of the generated signals, using commercial equipment as the gold standard. With the proposed device, values lower than or equal to the maximum permissible error defined by commercial equipment were obtained, demonstrating its reliability. The experimental results demonstrated a good performance and the viability of the developed system.