OASIS-UROS: Open acquisition system for IEPE sensors - upgraded, refined, and overhauled software

OASIS-UROS continues the previously published Open Acquisition System for IEPE Sensors (OASIS). While still building on the ESP32 microcontroller, this version improves the overall performance by switching to an SD card caching system and upgrading the analog-digital converter to an AD7606C-18, which has a higher resolution, provides eight channels, oversampling, and software-adjustable voltage ranges. Also improved is the IEPE front-end and power supply, as well as the firmware of the acquisition system, which can now achieve a sample rate of up to 36 kHz while sampling all eight channels. This paper documents the hardware and software of OASIS-UROS and provides all materials required to reproduce the open acquisition system. Lastly, the system was validated against commercial hardware and software in an experimental modal analysis context. This showed that the system performs close to the commercial one in some aspects with respect to the utilized test case. While OASIS-UROS cannot match the full performance of the commercial system, the developed system can be a viable alternative for students, people in academia, or smaller companies that have a constrained budget or require complete insight as well as adaptability of the hardware and software.