VibraTilt: Accelerometer & Gyroscope measurement app
© The Author(s) 2016
Received: 23 November 2015
Accepted: 6 April 2016
Published: 18 April 2016
Smartphones doubling up as laboratory equipment are increasingly in demand for convenience and portability. VibraTilt is a free smartphone app with a simple interface on both the iOS and Android operating systems that functions as both an accelerometer and a gyroscope. Leveraging on in-built sensors, the portable accelerometer bubble level can be used in labs to determine the tilt of surfaces. The gyroscope measures the rotation in three-directions-axes and their magnitude of change for calibrating equipment, measuring vibrations, stability of laboratory equipment, and measuring tremors clinically. For setting thresholds and visualization, a graph showing the change in the x, y and z values is incorporated in the Android version. Together with the customizable feature to record the number of shakes within a certain time frame, VibraTilt does more than unlock the smartphone to displace two equipment in the laboratory, but can be used in a variety of purposes.
Reproducibility is an important criteria of experimental research. As such, calibrated equipment and standardised measures are reported in experimental research articles. To ensure optimal conditions, additional devices for calibration or comparisons are extremely welcomed. With the widespread use of smartphones and mobile devices with multiple sensors, there is great potential for phones to be leveraged as research equipment themselves. They can function as the desired “second opinion” devices, and all that is required to unlock these potential are mobile apps (http://www.biospectrumasia.com/biospectrum/opinion/220592/use-smartphone-apps-biomedical-research). Mobile apps are now beginning to make an impact on research processes ranging from displacing equipment e.g.GelApp (Sim et al. 2015). Although a wide range of science-related apps have been created for aiding research, more remains to be done.
Both the gyroscope and accelerometer are widely used in scientific disciplines and daily life e.g. sports. Gyroscopes can be used to monitor earthquakes, precision engineering processes, neurological tremors such as Parkinson’s disease, or the stability of a process and ride (e.g. in protein crystallization processes and cell fusion procedures). Accelerometers measure the tilt and levelledness of surfaces that are important for the construction industry and sensitive cell seeding experiments or tilt-sensitive experiments in experimental laboratories. While they are useful, devices with such capabilities are not commonly available. Therefore, to address the need to make such devices more common for incorporation into the above examples, VibraTilt was developed as a free Android and iOS app to unlock the popular smartphone to have these additional functions.
Although there are numerous apps that unlock these smartphone sensors, the distinguishing feature of VibraTilt is the simple interface and the customizable threshold, sensitivity, and time limit for “number of shakes”. This allows VibraTilt to function at another level of use ranging from sports, clinical, precision engineering, calibration, etc.
VibraTilt for Android was developed using version 4.4 of the Eclispe Integrated Development Environment, Luna (https://eclipse.org/), as well as open source code from aChartEngine (http://www.achartengine.org/) for the generation of logarithmic graphs.
VibraTilt App for iOS was developed using version 6.3.2 of the Xcode Integrated Development Environment, utilising open source libraries: RGB colour sliders (https://github.com/eappel/RGBColorSlider) for changing the colour of the accelerometer bubble.
In the experimental laboratory, VibraTilt can be used to measure the stability and angle of surfaces for calibrating equipment and as a portable gyroscope for sensitive experiments. The key feature of measuring movement in a set time limit and magnitude allows the accelerometer function to do more than standardize shaking experiments, but also for neurological research involving tremors and even gait (LeMoyne et al. 2010). Outside the experimental laboratory, VibraTilt can be used for exercise and leisure purposes (pedometer, measuring mobile phone vibrations, or for determining if a piece of table/chair is tilted, etc).
VibraTilt functions as both a gyroscope and an accelerometer leveraging on the portability and convenience of smartphones/tablets. With added functions to calibrate, reset, and colour changes of the accelerometer together with the gyroscope measurement and graph function, much can be done with VibraTilt. In fact, VibraTilt marks the first such apps that is generic enough for both scientific research use, as well as for leisure.
Availability and implementation
VibraTilt (for Android and iOS) is freely available on the Google Play Store and Apple App Store as ‘VibraTilt’. More details on the app can be found at www.facebook.com/APDLab.
The ‘VibraTilt’ user guide is available at http://tinyurl.com/VibraTilt and a video tutorial is also available on the Google Play Store.
The accuracy of the gyroscope and accelerometer is dependent on the smartphone sensors, therefore variations are expected when used on different devices.
Funding: This work is funded by JCO1334i00050 grant, from the Joint Council Office, Agency for Science, Technology, and Research, Singapore. We thank Mr. Iman Fahman for helping with the accelerometer layout, Mr Sim Jia Zhi for technical assistance, and Mr. Dillon Lim for his help in this app note preparation.
Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
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