Low power network node for ambient monitoring and heart rate measurement

This paper focuses on the design of a low power sensor node that supports wireless communication via Bluetooth Low Energy (BLE) based on the TI System On Chip (SOC) CC2541 device. The network node integrates sensors for ambient monitoring, e.g. the recording of temperature, 3D acceleration and ambient light measurement. Recorded data can be sent via BLE to any remote device which supports BLE, e.g. a smartphone. In this paper, a heart rate sensor is implemented to demonstrate heart rate signal processing and its applications in sports. The on-board signal processing is performed on the MSP430 low-power microcontroller. As an example application, the data is wirelessly sent to a smartphone running Android OS for visualization. This paper describes the software and hardware development of the heart rate monitoring system including the signal pre-processing. The developed PCB has been integrated into a chest harness with integrated textile electrodes for heart rate measurement.