An energy harvested dosimeter for smartphones

• Main Author: Tay, Bai Xun
• Other Authors: Chang Joseph Sylvester
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/60870
• Institution: Nanyang Technological University

Smartphone are often used as a personal music player, resulting in prevalence of hearing damage by listening to loud and excessive music. Most users continue to underestimate the importance of maintaining daily safe noise dosage, exposing them to the risk of permanent noise-induced hearing loss. Therefore, it is vital to make the user of smartphone and music player aware of his/her daily noise dosage to prevent them from exceeding the safety limit. In this Final Year Project (FYP), the first personal noise dosimeter for IPhone was developed. The dosimeter used in this project is much smaller than the conventional bulky dosimeters for industrial use, it can be plugged to the audio socket of the IPhone easily, at the same time providing usual input to the microphone and output to the earphone. Furthermore, it is self-powered by drawing energy from the IPhone, and consumes little power when in operation which eliminates the need for batteries. The hardware and the software (noise dosage level algorithm) are designed to draw low amount of power, which can be adequately provided by the phone itself. The algorithm is further simplified and verified by computer simulation. The dosimeter will sample the correct voltage level and pass through an analog multiplier, performing the required operations that calculate the user's noise dosage. An integrator then compressed the signal, a simple program can then be used to calculate the noise dosage, if the noise dosage is higher than the recommended safety noise dosage, a blinking LED light or alarm will then alert the user that the accumulated noise dosage has exceeded the recommended safe threshold value. (IPhone) earphone characteristics have been taken into consideration to improve the accuracy of the algorithm. The dosimeter accuracy and functionality has been verified through experimental measurements and software simulation.