This application report describes how to build a digital heart-rate monitor using a MSP430FG439 microcontroller (MCU). The heartbeat rate per minute is displayed on an LCD. In addition, the application outputs a digital data stream via an RS232 serial port to allow EKG waveform display on a PC. PCB Gerber files, schematic, bill of materials, and firmware are provided in a zip file associated with this application report. The entire application runs using a CR2032 3-V lithium battery.