The risk of missing the next technological milestone in cars has never been greater. The automotive industry is changing at a pace that was unimaginable a decade ago, and one would be wrong to think that it’s only a matter of electrification. Electric cars are certainly getting more mainstream, but there’s also the “appification” of the vehicles’ interface thanks to new interactions with our smartphone brought by NFC. A few years ago, an NFC reader was a neat little feature to open doors. Today, customers are clamoring for more integration with their mobile devices, and the easiest way to offer differentiating functionalities is to rely on Near-Field Communication.

Thanks to the newfound popularity of mobile payment with phones and smartwatches, the public is more familiar with this technology. They understand that by bringing a tag, like those present in smartphones or cards, close to a reader, inductive coupling will allow the reader to get data from the tag and perform certain operations. However, as the automotive industry is finding new ways to use NFC readers, it’s crucial for decision makers and engineers to understand how they can take advantage of these latest developments. We decided to learn more about this by talking to two ST experts, Giuliana Curro and Rene Wutte, Technical Marketing Manager NFC/RFiD, to ask them how cars use NFC today, and how they will use it tomorrow.

NFC in Cars, Today

Life.Augmented Blog: Where are the most common places we find NFC modules in cars today?

Giuliana Curro: There are three primary locations: the door handle, the B-pillar between the front and back side windows, and the center console inside the car. The first two control the access to the vehicle by unlocking the doors and allow for very different designs. The space within the door handle is tiny, thus requiring slim components and antennas, while the B-pillar enables coils four times larger. The NFC module in the center console plays a very different role since it is responsible for authenticating and pairing a user’s smartphone with the vehicle, which in turn can influence the driver’s seat position and control of the ignition in keyless systems. We could also imagine a parent setting various speed limits when detecting a teenage driver.

ST’s NFC Solutions in Cars, Today

Life.Augmented Blog: How are we answering all these different needs?

Giuliana Curro: The trap for decision makers and designers is to think that all these applications require entirely different systems. The strength of an NFC Reader IC like the ST25R3914 is that it is flexible enough to fit into all these use cases. For instance, it’s vast operating temperature range of -40 ºC to +125 ºC means that it can sit anywhere in the car. Its automatic antenna tuning signifies that any detuning of the antenna due to environmental effects won’t affect performance since the component is smart enough to readjust the matching by using, among other things, parallel capacitors to optimize field strength and efficiency. Finally, the ST25R3914 also offers low-power consumption in card detection mode and can easily fit anywhere in the vehicle, from the door handle to the center console. And having only one IC means only qualifying one component, thus greatly simplifying designs and operations.

ST’s Ecosystem in Cars, Today

The X-NUCLEO-NFC05A1 on top of an STM8 Nucleo board
The X-NUCLEO-NFC05A1 on top of an STM8 Nucleo board

Life.Augmented Blog: These features are impressive, but the competition is though. Why should anyone working on an NFC module for a car choose our solution?

Rene Wutte: We’re not merely offering a product, but a path to an application. Anyone interested in the ST25R3914 can grab an inexpensive X-NUCLEO-NFC05A1 expansion board and start developing applications for it relatively quickly. We even offer a MISRA-C compliant firmware, the STSW-STM8-NFC5 that developers can begin testing on our NUCLEO-8S208RBbaseboard. We also provide an antenna matching graphical user interface, the STSW-ST25R004, to further facilitate developments. This hardware and software ecosystem is fundamental because it reduces the time to market. For example, by merely using the X-NUCLEO board, developers can take advantage of the automatic antenna tuning and the ultra-low power wake-up sequence. Engineers can then decide to use the same components in their final design, porting the code they used on the development boards.

ST’s Ecosystem in Cars, Tomorrow

Life.Augmented Blog: Isn’t an STM8 microcontroller too much for a door opener or too little for a center console?

Giuliana CurroThe STM8AF series of MCU for automotive applications offers a wide variety of packages and configurations, from 4 kB to 64 kB of Flash, enabling engineers to tailor their design to specific situations, whether they are working on the door handle, B-pillar, or center console. It is always more practical for developers to work with the same MCU architecture as they can adapt the hardware configurations to their needs. The strength of a development board like the X-NUCLEO-NFC05A1 is that it makes it easier to take advantage of the STM8 Development Tools that enable developers to implement all relevant hardware feature. The STM8AF series can interface with the NFC reader while its CAN controllers allow it to communicate with the rest of the car, making it an excellent choice for automobile applications.

The Arrival of Smartphones in Cars, Today and Tomorrow

Unlocking a car with the NFC tag of a smartphone
Unlocking a car with the NFC tag of a smartphone

Life.Augmented Blog: Why car manufacturers demand such a feature-rich NFC reader and MCU?

Rene Wutte: It reflects a shift in mentality from major car manufacturers. A couple of years ago, engineers needed to convince decision makers to use NFC in vehicles. Then Mercedes adopted our ST25R reader in their E-Class models. Now, decision makers want a reader because keyless entry and smartphone pairing are all the rage. In fact, the real differentiating factor is the ability of a design to be future-proof. An ST25R3914 NFC reader and an STM8 MCU are so efficient that teams know they can use them for multiple years, which will enable them to focus on other aspects of the vehicle as they put out a new model each year. It is particularly crucial for center consoles that now play an intermediary role between the car’s display and the smartphone that projects its operating system and graphical interface.

Mobile Operating Systems in Cars, Tomorrow

Life.Augmented Blog: Does it mean that NFC in center consoles is the beginning of the end for the infotainment systems from car makers?

Giuliana Curro: Not really. Automobile companies will still want to display information about the car, offer basic FM features, and provide some interface to differentiate themselves from the competition. However, they must also account for users wanting to use systems from smartphone makers and must provide components powerful and robust enough to ensure that these operating systems can adequately display on their vehicles a few years from now. There are also future innovations, such as the popularization of wireless versions of MirrorLink, which will mean that smartphones will no longer need a cable to connect to a car, and NFC can assist with the initial setup. NFC is also a gift to car makers that can now offer new features, such as customized settings based on the user’s phone, thus further a brand from its competitors.

Wireless Charging in Cars, Today

Life.Augmented Blog: What new challenges must designers now face with the arrival of NFC in the car?

Rene WutteThe most immediate challenge is the use of Wireless Qi charging systems next to the center console’s NFC reader. Integrating both solutions with automotive-grade components in a simple and efficient design is far from evident, but we are already showing demo kits that would enable engineers to offer both features fairly simply. Our partners, such as ROHM, already provide this sort of turnkey solution, which includes a 15 W power transmitter, our ST25R3914, and an STM8A. It is probably one of the best testaments that our solutions aren’t hypothetically interesting but are already changing the industry with designs that will integrate tomorrow’s vehicles to answer the current and future needs of drivers and passengers. Additionally, the ST33 secure element, available separately, perfectly fits to the Qi authentication and digital key requirements, which will future-proof a design.

MISRA-C Compliant Firmware, Today

Life.Augmented Blog: A turnkey solution is fantastic, but we already hear developers scream in pain because they’ll have to ensure their code is MISRA-C compliant.

Rene WutteIt’s the reason why our STM8 firmware for the X-NUCLEO-NFC05A1, which includes our ST25R3914, is already MISRA-C compliant. When developers start working on our components, they have access to free source code that already meet the various guidelines from the Motor Industry Software Reliability Association (MISRA). The guidelines themselves promote the creation of a code that’s safe, secure, portable, and reliable, but ST goes beyond by offering additional features. We have codes to protect the NFC cards, such as credit or keycards, from destruction by the Qi charger, and can cover various cards (ISO14443A, ISO14443B, and FeliCa, for the Japanese market), as well as Bluetooth and Wi-Fi pairing to help developers offer even more possibilities to the final users.