MOD-EKG is a digital heart-rate monitor using TI's MSP430FG439 microcontroller. The heartbeat rate per minute is displayed on the LCD. In addition, the application on the MCU outputs a digital data stream via an RS232 serial port. This allows you to have the EKG waveform display on a PC or some other system capable of processing the data and displaying it graphically. The serial signals are available through the UEXT port. You can connect this module to any system that has a UEXT header. To connect to a PC, you can use the MOD-USB-RS232 that converts serial signals from UEXT into USB and vice versa.
An electrocardiogram, also called an EKG, is a graphic tracing of the voltage generated by the heart muscle during a heartbeat. In this application, the EKG waveform is used by the MCU to measure the heartbeat rate. Because heartbeat calculation is the major focus, the electrodes are simplified into two connections: one for the right hand and one for the left hand. You just hold the board by the HR1 and HR2 pads.
Digital Heart Rate Monitor Board Features
- Microcontroller: MSP430FG439 with pre-loaded firmware
- EKG amplifiers realized with INA321EA
- 14-pin JTAG connector in case you want to reprogram the MSP430 MCU (board also can be powered through JTAG)
- UEXT connector (see below)
- LCD with seven 14-segment digits, four 7-segment digits, decimal points, colons, arrows, bars, etc.
- Lithium coin-cell 3V battery holder (battery not included)
- Extension headers for all microcontroller ports (no connectors mounted)
- Right and left hand contact electrodes — HR1 and HR2
- Two status LEDs
- Two user buttons
- Switch for selecting Battery or UEXT power supply
- Based on Texas Instruments application note SLAA280a
- FR-4, 1.5 mm, soldermask, component print
- Dimensions: 76.20 × 71.12 mm (3.00 × 2.80")
UEXT Connector The UEXT connector provides a solderless way to connect this module as an add-on peripheral to a system with a microcontroller. There are dozens of microcontroller systems and development boards that can connect to this module via UEXT using the supplied cable. Click on the architectures below for lists of compatible boards:
Digital Heart Rate Monitor Board Resources