The RFID world is more than your Oyster….

….it can also provide cheap device connectivity.
Flexible RFID application

I like to think that I am generally well informed about the possibilities of wireless communication systems, but a while ago I was working on a project in the consumer product sector using an interesting feature of RFID technology which I had never seen before.  It made me realise that there is a whole new world of user interaction with consumer devices which is now possible with the help of NFC capable smartphones.

Most of us are familiar with the idea of RFID wristbands for identifying people at music festivals, RFID cards for door entry systems in the office and smart payment cards such as London’s Oyster cards.  What is less well known is that other exciting applications are made possible by the powerful data-measurement and data-logging functionality of the latest RFID chips, in combination with smartphones and tablets which include NFC technology that can communicate with these chips.  The huge consumer take-up of mobile devices equipped with NFC communications opens the door to the development of new consumer products which build a deeper level of user engagement and the ability for manufacturers to collect valuable product and market information.

It is not the purpose of this article to describe the technology in detail, but a basic understanding of the capabilities of NFC (Near Field Communications) and RFID (Radio Frequency Identification) is useful to recognise the possibilities.  NFC is a recent development of the more general RFID technology which has existed for many years.  Both terms describe standards for wireless data communications between devices at relatively low data rates over short range.   NFC technology is being increasingly built into smartphones and tablets (since this article was originally written Apple have released the iPhone 6 with NFC hardware, but at the moment it can’t be accessed by anything apart from ApplePay) – it operates at a range of a few centimetres, and supports two forms of communication:

  • Two-way peer-to-peer – two NFC equipped devices (phones or tablets) can exchange information when held in close proximity.  The data exchanged may be used directly, or more commonly used as a simple means of pairing, to set up another communications channel (Bluetooth or Wi-Fi Direct).  This is the basis of Android Beam on various Android devices and S Beam, from Samsung
  • One-way – an NFC equipped phone or tablet can read information from an RFID tag.  The tag is typically an inexpensive unpowered passive device, which can be mounted along with the associated antenna in a consumer device or even on a flexible surface such as paper

It is the one-way communications capability that opens exciting new possibilities for consumer-facing products.  In many cases these would not be feasible if the product had to bear the high cost of the NFC reader – but many consumers already have that on their mobile device, and are itching to find exciting things to do with it.

As a first step, a simple application is smartphone automation.  Cheap passive RFID tags can be located on your desk or in your car.  When the smartphone is placed near to the tag it runs an application which can change the phone’s behaviour – perhaps it goes into silent mode in the office, or hands-free mode in the car.  But this is just the start.

Reading temperature with RFID
Mock-up of product displaying temperature with RFID connectivity

A simple passive tag returns a fixed ID when read by the smartphone, a bit like reading a bar code – but it doesn’t have to be that simple.  An unpowered passive tag can also have data measurement and data logging capabilities, with the ability for instance to read an analogue value.  A smartphone or tablet can collect critical and variable information from the tag.  This could be a parameter such as temperature, pressure, humidity, voltage or current.  If such a chip is embedded in a consumer product, the user can read the live value of a parameter from the product by running an app provided by the product manufacturer.  The parameter’s value can be time-stamped, stored and displayed by the smartphone or tablet, and sent into the internet Cloud via the mobile device’s internet connection.  Remember, although this RFID device is reading an analogue parameter, and transmitting that value back to the smartphone, it requires no power source – it harvests all the power it needs from the signal it receives from the smartphone or tablet.

If the product is such that the tag can be provided with power (only a tiny amount is required), then the tag can operate in power assisted passive mode with a real-time clock.  This gives the system the ability to take periodic sensor readings autonomously, rather than purely on demand.  When interrogated with a smartphone or tablet via NFC, a series of time-stamped readings will be available, revealing the history of the parameter, so you could look at the temperature profile an item of food as it travels from the supermarket to your freezer, the moisture profile of the soil in your greenhouse, or changes in your blood sugar level over a period of time.

For more complex products, an NFC chip can work alongside a microcontroller, so that the NFC interface can provide a rich set of data covering many parameters.

The common factor with all of these systems is that the product end of the system is relatively cheap and simple – a passive RFID tag can cost less than $1.  A custom design for a high volume product could be much cheaper.  The customers’ own smartphones and tablets are providing the raw processing power, user interface and internet connectivity.

When customers are able to interact with a product using their familiar mobile devices, they become more engaged with that product.  With a well designed app, the product manufacturer can support that product interaction, promote a closer relationship with the customer, the development of a customer community and social networking links.  As a side-effect, the manufacturer can also gather data about their product and their customers, providing both technical and marketing opportunities.

With Internet of Things being the buzzword of the day, RFID technology could be an effective way of allowing low cost consumer devices to join more expensive products in having an internet presence.