Bluetooth low energy (Smart) Heart rate variability sensor demo app for Android
This app searches for nearby BLE devices and connects to heart rate sensor service. It shows hear rate (average pulse) and heart rate variability (beat-to-beat interval or RR data). The app also has a graphical demo of pulsing dot for real-time biofeedback monitoring of hear rate variability showing nicely how breathing rate affects heart rate variability.
Heart rate variability could be used to calculate different things like training effect on sports, sleep quality, stress and relaxation effects since it mirrors parasympathetic nervous system activity.
BLE is a nice since it has open protocol for transmitting data like heart rate here. It makes setting up a development environment relatively fast and you can concentrate on doing you actual business logic.
Install the app from Google Play Store
Connect heart rate BLE belt on your chest or wrist. Start the app and scan for BLE devices. Select heart rate sensor and wait for the GATT hear rate service to be found. Heart rate data values starts to update on the screen. Press demo button to show a graphical demo of heart rate variability. You will get nice graphics when you sit down relaxed. Try some slow deep breaths. The dot shows your heart rate variability cut from 700 milliseconds corresponding to pulse of 87. If your pulse is higher no dot is drawn. You can select GATT information services to read other data on the device.
Android BLE seems to be slow to connect on first time. Please wait a minute or two to get the heart rate reading. If device is disconnected some times switching Android bluetooth off and back on will help to reconnect. Make sure your chest belt is well moisturized to get a good contact.
Most of the bluetooth BLE sensor handling are from TI Sensor Tag project by:
Polygon drawing from Pro Android book by APress and Sayed Hashimi and Satya Komatineni.
The MIT License (MIT) Copyright (c) 2013-2014 Steven Rudenko and Olli Erjanti Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.