The Implementation of Cost-Effective Data Acquisition System for Acoustic Emission Sensor using Variable Gain Preamplifier and STM32F4 Microcontroller Interface

this paper presents the Data Acquisition (DAQ) system that particularly collects Acoustic Emission (AE) signals in the range of 1 kHz to 500 kHz from the sensor, and transmits to a personal computer for further signal analyses. The proposed system comprises two major components, i.e. a variable gain preamplifier and a STM32F4 microcontroller. The variable gain preamplifier is implemented using BiMOS operational amplifier model CA3140 which provides relatively high input impedance and high-speed performance. The signal is subsequently digitized by STM32F4 Microcontroller and transmits to data analysis software via serial communication (RS232). Simulations are performed through Orcad PSpice and a MATLAB Simulink. Signal quality analysis involves frequency response, Total Harmonic Distortion (THD), and Power Spectral Density (PSD). Experiments show that the proposed system offers a potential alternative to commercially available data acquisition systems.