This work presents the design of a portable device for the recording and transmission of an ECG signal using the AD8232 microchip as the analog front end (AFE). Starting with the manufacturer’s evaluation board for this chip, then a SMD-to-DIP adapter with breadboard‐friendly Arduino microcontroller and breakout boards, until reaching a custom PCB. The analog ECG signal from the AFE output was digitized using one channel of the 10-bit ADC of the ATmega328 microcontroller contained on the Arduino Nano board 3.0. Besides this hardwired development, a simulation was also used in the analog circuit design with the SPICE Multisim software and related macromodel library to investigate system stability. The digitized ECG signal can be transmitted by serial cable, and recorded with a microSD card adapter along with the date and time stamp data of the sample capture (real-time clock provided); for wireless transmission the shield HC-06 was used. Transmission via bluetooth to a PC us-ing LABVIEW software or to a smartphone with Android system can be achieved. Besides the hardware filters in the AFE stage, digital filtering by means of simple difference equations was included as an option. A menu was incorporated to choose from the several modes of operation of the device. The ECG test signals were obtained from a patient simulator (SimCube) and real pa-tients. The result obtained from this work was a portable ECG system prototype with serial transmission, SD recording, and bluetooth transmission, for monitor-ing applications, and complies with electrical safety regulations and medical equipment design.