Autonomous NFC-enabled temperature monitoring label
Sirén, Hannes Olavi (2018)
Sirén, Hannes Olavi
2018
Sähkötekniikka
Tieto- ja sähkötekniikan tiedekunta - Faculty of Computing and Electrical Engineering
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Hyväksymispäivämäärä
2018-12-05
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tty-201811212687
https://urn.fi/URN:NBN:fi:tty-201811212687
Tiivistelmä
This Thesis concentrates on a practical customer-oriented project implemented for a Finnish company called Confidex. The subject of the Thesis was to design and implement an autonomous temperature monitoring device that operates using NFC. The Thesis can be divided into hardware and software design and validation of the finished solution.
Hardware designing consisted of creating an NFC antenna that resonates at the desired frequency of 13,56 MHz with the IC. The IC selected for this Thesis includes an integrated temperature sensor. Using the sensor autonomously requires the use of an external power source. The different types of power sources and their operating principles are also discussed and studied in this Thesis alongside with different attaching methods. This Thesis aims to provide relevant information about the different design aspects of the solution that can be used as a basis of further research and decision making.
The choices for external power sources were a conventional coin-cell battery, flexible thin-film battery, printed super capacitor and a photovoltaic cell. The coin-cell was specified to be the most affordable choice. The studied methods of attaching the power source were soldering, ultrasonic welding and both conductive adhesive and transfer tape. Different methods were compared to each other by testing their mechanical strength by tearing the power sources off from antenna inlays and discussing the difficulty of integration to mass production. The results show that soldering provides the strongest mechanical bond, but the conductive transfer tape is the easiest method to integrate in mass production without additional machinery investments.
An Android application was implemented so that the user could operate the designed tag. NFC capabilities are well supported over a wide variety of physical devices that use Android as an operating system. This Thesis describes the process of software design and discusses the functionality of the application as well as the properties of the user interface. The application can be used to read measurement data from the tag, setting the IC parameters and exporting the results in csv format.
The performance of the finished prototype products was ensured with several experiments measuring, for instance, the accuracy and setting time of the sensor. Practical experiments were also made to ensure the practical operation of the tag and software. The product was used to characterize the temperature changes inside a refrigerator and a freezer as well as to compare different thermos containers and their ability to maintain the temperature of their contents. The device was validated to be a viable temperature monitoring solution.
Hardware designing consisted of creating an NFC antenna that resonates at the desired frequency of 13,56 MHz with the IC. The IC selected for this Thesis includes an integrated temperature sensor. Using the sensor autonomously requires the use of an external power source. The different types of power sources and their operating principles are also discussed and studied in this Thesis alongside with different attaching methods. This Thesis aims to provide relevant information about the different design aspects of the solution that can be used as a basis of further research and decision making.
The choices for external power sources were a conventional coin-cell battery, flexible thin-film battery, printed super capacitor and a photovoltaic cell. The coin-cell was specified to be the most affordable choice. The studied methods of attaching the power source were soldering, ultrasonic welding and both conductive adhesive and transfer tape. Different methods were compared to each other by testing their mechanical strength by tearing the power sources off from antenna inlays and discussing the difficulty of integration to mass production. The results show that soldering provides the strongest mechanical bond, but the conductive transfer tape is the easiest method to integrate in mass production without additional machinery investments.
An Android application was implemented so that the user could operate the designed tag. NFC capabilities are well supported over a wide variety of physical devices that use Android as an operating system. This Thesis describes the process of software design and discusses the functionality of the application as well as the properties of the user interface. The application can be used to read measurement data from the tag, setting the IC parameters and exporting the results in csv format.
The performance of the finished prototype products was ensured with several experiments measuring, for instance, the accuracy and setting time of the sensor. Practical experiments were also made to ensure the practical operation of the tag and software. The product was used to characterize the temperature changes inside a refrigerator and a freezer as well as to compare different thermos containers and their ability to maintain the temperature of their contents. The device was validated to be a viable temperature monitoring solution.