Performance Analysis of Bluetooth Audio Devices As Wireless Data Acquisition Systems
Universidad Nacional Autónoma de México, Roberto Giovanni Ramírez-Chavarría, Omar Y. López-Rico, Universidad Nacional Autónoma de México · Memorias del Congreso Nacional de Control Automático · 2023
Data acquisition is an ubiquitous process to gather information about real-world phenomena to be processed in the digital domain. Currently, portable and wireless devices have become attractive devices for measuring several processes. However, when a high-sampling-rate is required, data acquisition systems (DAS) are still expensive and targeted at a very small niche market. Moreover, low-cost DAS are affordable but they are resource-limited mainly resulting in a low-sample-rate. Interestingly, audio-based systems are versatile, their sampling frequency ranges from 1 kHz to 192 kHz, and support input voltages from ±1.0 V at 16-bit resolution. Furthermore, Bluetooth audio devices (BTAD) are currently, popular in personal devices, which stream bunches of data using electromagnetic waves in the radio-frequency band. Nonetheless, audio-focused devices are optimized to respond to signals within the audible spectral range (20 Hz to 20 kHz), which represents a limitation to work as general-purpose DAS. In this work, we assess the advantages and limitations of low-cost BTAD to work as wireless DAS by increasing its performance and reliability. For this purpose, we introduce a robust data processing technique based on spectral analysis. Finally, the functionality of different BTADs is evaluated over a frequency range out of their native limits, and a compensation method for the frequency bias is proposed.