Audio storage and playback in low-cost embedded device

• Main Author: Sim, Kae Wanq
• Other Authors: Goh Wooi Boon
• Format: Final Year Project
• Language: English
• Published: 2016
• Subjects: DRNTU::Engineering::Computer science and engineering
• Online Access: http://hdl.handle.net/10356/66828
• Institution: Nanyang Technological University

Human perception to sound is weaker than most animal in the world. Human can only hear sound within specific range in term of frequency, 20 Hz to 20 kHz. However, ‘sound’ brings giant impact on human physically and mentally, in both good and bad ways, and also plays an important role in conveying information. In this project, the author implemented an audio playback system on low-cost device with System Workbench for STM32 (SW4STM32). The audio playback system comprises a STM32F411e-Dicsovery board and breakout board for microSD card. The system retrieves audio data from audio source-microSD card, and playback thru built in DAC on the Discovery board. Upon the system implementation, to understand the limitation and improve system performance, evaluation and several tests were done on three aspects: buffer size, audio input rate and audio output rate, to determine their influence on audio playback quality. The playback under different were played and recorded, then analysis using Goldwave. At the end of the tests, the system is able to play audio with sampling frequency up to 96000 Hz (DVD audio quality). Although the performance is improved, this audio playback system only supports audio files in wave format. For storage and cost efficiency, it is suggested to be improved for supporting more kinds of format. In the other hands, tests are suggested to run using high accuracy equipment for higher accuracy.