A flexible Raspberry Pi-based data logger platform for Modbus sensors with Ansible deployment

Area of Science:

• Environmental Science
• Environmental Monitoring
• Sensor Networks

Background:

• Environmental monitoring requires reliable and cost-effective data logging solutions.
• Deploying sensor networks can be complex and time-consuming.
• Open-source platforms offer flexibility and accessibility for research.

Purpose of the Study:

• To present LibrePiLogger, an open-source data logging platform for environmental monitoring.
• To demonstrate a system utilizing Raspberry Pi and Modbus sensors over RS-485.
• To provide a cost-effective and easily deployable solution for researchers.

Main Methods:

• Developed an open-source data logging platform using Raspberry Pi.
• Integrated the AtmosPyre Python library for Modbus sensor communication.
• Utilized Ansible for automated deployment of sensor networks.
• Described minimal and maximal hardware configurations.
• Implemented drivers for CO2 and 222Rn sensors.

Main Results:

• The LibrePiLogger system enables data logging from Modbus sensors via RS-485.
• Deployment is simplified through Ansible automation and a YAML inventory file.
• The system supports various Raspberry Pi configurations and sensor types.
• Continuous CO2 and 222Rn monitoring in a karst environment has been successfully demonstrated since spring 2025.
• Hardware costs are low, ranging from 54 to 63€.

Conclusions:

• LibrePiLogger provides a reliable, cost-effective, and user-friendly platform for environmental data logging.
• The open-source nature and automated deployment facilitate widespread adoption in research.
• The system demonstrates robust long-term performance for continuous monitoring applications.