ERSP - Pedometer

Energy-efficient Real-time Smartphone Pedometer (ERSP) energy-efficiently infers the real-time count of human steps using the smartphone accelerometer. It functions regardless of the smartphone on-body placement and orientation.

Installation and running
1. Download and install the apk.
2. Select menu and click start to commence recording the real-time human step count.
3. To pause the application select menu and click pause. The human step count is retained.
4. To reset or stop the application select menu and click stop. The human step count resets to 0.
5. Select menu and click preferences to select the desired background sensor tunnel. The default is screen lights enabled. This is required because the screen lights or CPU need to be running to invoke the accelerometer in background mode.

Displaying and downloading the results
Depending on the options selected ERSP captures user mobility data. The data is logged into a file named ersp.log and errors logged into ersp_error.log. The data is saved in csv format. All files are written to the root directory in the local phone storage. The following user data is captured:

• Timestamp: system timestamp in the format dd/MM/yyyy HH:mm:ss
• No of steps: number of human steps
• No of Peaks: number of peaks(P)
• mm: the difference between the maximum peak and trough values and the corresponding minimum values every 2 seconds (8 accelerometer samples).
• Tpt: the total count of peaks (P) and troughs (T).
• Longitude: is the longitude of the location fix (if GPS is enabled via the preferences option).
• Latitude: is the longitude of the location fix (if GPS is enabled via the preferences option).
• Battery level: specifies an integer value of the remaining battery from 0 to the battery scale.
• Battery scale: specifies an integer value of the maximum battery level. For all the experiments this value was 100.
• Temperature: is the current battery temperature in Celsius.
• Voltage: is the current battery voltage level in millivolts.