The Bluetooth® Low Energy (BLE) heart rate monitor reference design demonstrates the implementation of a wireless electrocardiogram (ECG) acquisition system. It features the Kinetis® KW40Z system on chip (SoC) which includes an ARM® Cortex® M0+ processor together with a 2.4 GHz radio for BLE and 802.15.4.
The ECG signal is obtained from the finger tips and processed by the Kinetis KW40Z SoC. Then, the user’s heart rate is calculated and transmitted to a smartphone application using BLE. The reference design can be powered by a Li-Ion coin-cell battery. Due to the low-power features of Kinetis KW40Z MCU, a 3.6V 200mA/h Li-Ion coin-cell rechargeable battery can provide the power of up to 40 hours of continuous use. The NXP® MC34671 is in used as a battery charger solution for the device.