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Top1. Personal Mobile Sensors
Mobile phones and tablet computers are equipped with an increasing range of sensors. Originally introduced to control interface functions, such as increasing the screen brightness in sunlight or orienting the display when the device is turned, they can also offer a personal science toolkit to explore the surrounding world. This has been made possible now that sensors in mobile devices are becoming more sensitive and better calibrated and the controlling software emits a rapid stream of data at a full range of levels.
The sensors come in four broad types:
- A.
Motion sensors measuring acceleration and rotation using a 3-axis coordinate system (e.g., accelerometer; tilt sensor),
- B.
Environmental sensors measuring ambient conditions (e.g., thermometer; barometer; light),
- C.
Position sensors measuring the physical location of the phone (e.g., GPS; proximity to an object), and
- D.
Body sensors (e.g., fingerprint, heart rate).
Software applications (apps) for mobile phone sensors include obvious ones for noise1 and light2 sensing, but also some ingenious apps such as GammaPix3 (Drukier, Rubenstein, Solomon, Wójtowicz, & Serio, 2011) that employs the camera to detect ionising radiation and Zephrus4 that detects wind speed from the device’s microphone.
Consumer mobile sensors have been applied to crowdsensing (Ganti, Ye & Lei, 2011) where members of the public are recruited in projects to collect environmental data such as levels of pollutants in the atmosphere or rivers. These require additional low-cost sensors attached to mobile phones. Citizen environmental projects using just the sensors on standard mobile devices include monitoring traffic conditions (Mohan, Padmanabhan & Ramjee, 2008) and sharing pictures of daily meals by people controlling their diets (Reddy et al., 2017).
This paper describes a toolkit for learning that makes available the full range of motion, environmental and position sensors in a mobile device. The Sense-it app5 was first developed in 2013 for the ‘nQuire: Young Citizen Inquiry’ project, funded by Nominet Trust, and has since been tested with students in a design-oriented college (Herodotou, Villasclaras-Fernández & Sharples, 2014) and as part of a research study of citizen-initiated meteorology (Aristeidou, Scanlon & Sharples, 2015a). It engages people of all ages in practical science activities where they have control over not only the data they collect, but also the initiation of investigations and sharing and discussion of findings. The intention is that people of all ages will experience the excitement and challenge of doing science by employing their own devices as environmental probes in locations around their neighbourhood, or further afield such as on holiday, and learn from the process.
A more recent initiative by Google has developed the Science Journal app6 for running science investigations on smartphones. It has some similarities to Sense-it in that it enables the user to record and compare multiple trials. However, the Science Journal app currently only includes the light sensor, microphone and accelerometer. While it allows the user to make notes on a trial, it does not provide facilities to share the data with other users, nor for members of the public to initiate new investigations. At the time of writing, the Science Journal website proposes five investigations7, two of which require additional equipment. The nQuire-it website currently proposes 32 investigations, with seven involving the Sense-it app.