Since 2005, the RFID division of the ElectroMagnetic Lab Lecce (EML²) at the University of Salento’s Innovation Engineering Department, in Italy, has been researching and creating RFID-based sensor solutions. Recently, Danilo De Donno, a postdoctoral researcher at EML², working under his advisors Luciano Tarricone and Luca Catarinucci, developed RAMSES (RFID Augmented Module for Smart Environmental Sensing), a fully passive UHF RFID tag with sensing and computing capabilities. De Donno took time to answer a few questions on RAMSES, and why they chose to use Impinj Monza tag chips in the design.
What is RAMSES? What is its use case?
RAMSES exploits an RF energy harvesting circuit to power an ultra-low-power microcontroller unit (MCU), an Impinj Monza X-2K I2C-RFID IC, and several digital sensors, specifically temperature, barometric pressure, ambient light, and 3-axis acceleration. Sensor data measured by RAMSES is stored into the user memory of the Monza X-2K chip and is readily accessible by conventional UHF Gen2 RFID readers.
RAMSES has been conceived with the RFID sensor network concept in mind. In other words, we believe that RAMSES zero-power operation and small form factor could open up novel application spaces where long-lived, unobtrusive devices are paramount, e.g. in home/environmental sensing and factory automation scenarios.
What did you set out to accomplish with your research?
In the last few years, the possibility to integrate sensing and computing capabilities in passive UHF RFID tags has raised broad interest among academic researchers and RFID manufacturers. Though a small number of both commercial and research solutions for RFID-based sensing are already available, none of them encompass all the primary requirements conceivable for future RFID-based sensing applications, e.g., full compliance with RFID standards and regulations (most devices need specific settings for the reader or support only a subset of Gen2 commands), a satisfactory operating range (at least comparable to that of conventional identification-only passive Gen2 tags), a variety of on-board sensors, high expansibility and programmability. In 2012, when we designed the first RAMSES prototype, we set out to develop a device which was able to satisfy all the aforementioned requirements.
What are RAMSES' results? What are the benefits?
In the July 2014 issue of IEEE Transactions on Instrumentation and Measurement, we have presented a RAMSES prototype fabricated on a printed circuit board using low-cost, off-the-shelf discrete components. RAMSES has been extensively tested through experiments conducted both in lab and real-world application scenarios. Specifically, in a former test, we used RAMSES to monitor indoor ambient temperature and light conditions over a 24-hour observation period while, in a latter test, static acceleration measurements on a parcel were performed by RAMSES in order to verify its ability to catch abusive handling events during a shipment.
The recorded results demonstrate RAMSES' ability to harvest the RF energy emitted by an interrogator placed up to 32.8 feet (10 meters) away and autonomously perform sensing, computation, and data communication. Furthermore, for applications requiring larger operating distances, RAMSES can operate in a battery-assisted passive (BAP) mode, extending the communication range up to 22 meters (72 feet).
Why did you choose to use Impinj’s Monza X-2K chip in the design?
To our knowledge, Impinj was the first company to release a new-generation UHF RFID chip featuring, in addition to the Gen2 air interface, a wired I2C interface. Therefore, when in 2012 we conceived the RAMSES idea, Impinj’s Monza X-2K was what we were looking for. Actually, following Impinj vision, several companies are breaking into the market with Gen2 chips featuring SPI or I2C interfaces but, to our knowledge, none of them can be compared to Impinj’s Monza X-2K in terms of performance and key functionalities. More specifically, the main aspects which drove us to choose Impinj’s Monza X-2K are:
- The exceptional read/write sensitivities;
- True3D antenna technology enabling orientation insensitivity;
- The possibility to boost read/write sensitivities in battery-assisted passive (BAP) mode;
- Write wakeup (WWU) mode for waking up the sleeping microcontroller when a memory write is performed over the Gen2 interface;
- QT technology for read-range control and data privacy over the RF link
What are next steps for RAMSES? What can someone do with it today?
We believe that the validated RAMSES capabilities make it mature for industrialization. In the meantime, we are working on a new RAMSES release featuring a miniaturized antenna system, hybrid solar-RF energy harvester, and LCD display.
RAMSES could be employed in a variety of application contexts as it is. Let’s consider, for instance, all those applications where, along with traceability information, environmental parameters should be monitored. Cold chain is just an example, but many others are possible. Additionally, we are testing a customized RAMSES prototype in a cow farm for automatic body temperature recording and permanent animal identification for livestock. In this way, besides providing farmers with an electronic case history for each animal, RAMSES will be able to promptly generate alerts as soon as the cow’score temperature approaches a critical, predefined threshold, thus enabling, de facto, rapid interventions.
RAMSES wiki page can be viewed here.
Dr. Danilo De Donno