High-precision multi-sensor temperature monitoring system for pharmaceutical testing with MQTT-over-Ethernet connectivity

Table of Content

Introduction:

This PCB module version 2.0 was designed as an upgrade for a dissolution tester to measure temperature using sixteen (16) individual PT100 temperature sensors. The previous version supported eight (8) sensors and lacked central network ethernet connectivity. The update was aimed to enhance sensor capacity, add network connectivity via ethernet (IEEE 802.3 standard), support MQTT protocol for data exchange, POE & remote control via commands, achieve higher resolution (0.1°C) and accuracy (±0.2°C).

What we did?

The new version features significant hardware and firmware upgrades developed by the Oxeltech hardware & firmware team. The team implemented several key improvements to the system’s PCB design and capabilities:

Integrated Power over Ethernet (PoE) functionality, allowing the device to receive both power and data through a single Ethernet cable, simplifying installation and reducing cable clutter
Expanded sensor capacity through an SPI-based ADC chip implementation that handles sixteen (16) PT100 temperature sensors with high precision
Developed RTOS-based firmware ensuring real-time operation and fast sensor data acquisition
Implemented Ethernet connectivity with MQTT protocol support for seamless communication with network PCs, enabling real-time sensor data sharing and remote command control
Achieved precise temperature measurement with 0.1°C resolution and high accuracy (±0.2°C)
Enhanced system reliability through optimized hardware design and component selection

These hardware and firmware enhancements significantly improved the dissolution tester’s performance, reliability, and connectivity options while maintaining compliance with pharmaceutical testing standards.

Technologies Used: CMSIS-RTOS (Real-Time Operating System), SPI (Serial Peripheral Interface), MQTT (Message Queuing Telemetry Transport), Ethernet connectivity (IEEE 802.3 standard), POE, PT100, Analog & Mixed Signal PCB Design, Altium

Performance Evaluation: Oxeltech enhanced the sensor capacity, added connectivity via Ethernet, and improved precision and accuracy of temperature monitoring which is crucial for dissolution testing.

What feedback did we receive?

Positive feedback on the module’s accuracy, real-time responsiveness, and Ethernet integration. Client appreciated the expanded sensor capacity and seamless communication capabilities. Rated very high for meeting specifications and enhancing operational capabilities with Ethernet connectivity.

Market Analysis and Alignment

Our Experience: Gained expertise in RTOS-based firmware development, sensor integration, MQTT protocol implementation, and Ethernet communication.
Market Analysis: Aligned with market trends towards higher precision, connectivity, and data integrity in medical and laboratory equipment.
Alignment with Values: Project aligned with our commitment to innovation, reliability, and customer-centric solutions in medical instrumentation.

Conclusion

Project Impact: Significantly improved temperature measurement capabilities with enhanced sensor count, reliable Ethernet communication, and adherence to stringent accuracy requirements for dissolution testing.
Lessons Learned: Importance of real-time performance and secure data transfer in medical devices, need for seamless integration of communication protocols.
Future Recommendations: Explore AI integration for predictive maintenance, expand sensor capabilities for broader application in medical research and testing, and continue optimizing Ethernet communication for efficiency and reliability.