LCAS: A Low-Cost, Open-Source Accelerometer System for Structural Vibration Monitoring

This study introduces LCAS, an open-source, low-cost system for triaxial acceleration acquisition. It integrates three accelerometers (model MPU9250) operating in parallel via a serial communication multiplexer, an Arduino Pro Micro microcontroller, and data storage on a microSD card. The system was experimentally validated using a shake table and through field tests, which included both ambient and forced vibration measurements on structural elements. LCAS employs a multi-sensor root mean square configuration to reduce noise, operates at a sampling frequency suitable for civil engineering applications (≥150 Hz), and features a rigid resin encapsulation to enhance mechanical stability. Experimental results demonstrate consistent behavior and sufficient stability for structural monitoring, achieving performance comparable to commercial systems at a fraction of the cost. Furthermore, LCAS supports data acquisition and visualization through open-source tools such as CoolTerm and the Arduino platform, making vibration monitoring more accessible in resource-limited settings. This accessibility makes LCAS particularly valuable for regions with high seismic risk and for developing countries, where affordable and reliable structural monitoring solutions are urgently needed.
The following files are included in the present repository:

- PCB files
- Software file
- Case design files