Editor's Note: Bluetooth® Smart is the latest addition to the Bluetooth Specification and it uses Bluetooth low energy technology to enable the Internet of Things (IoT) for products that operate on small coin cells for years. How is that possible you may ask? Bluetooth low energy was designed to be low power, only waking up from time to time to transmit small amounts of data with rather high latency in a range that covers up to a couple of meters. ECN will be hosting a 6-part series from Texas Instruments about the benefits of using BlueTooth Smart in industrial applications. The blogs will be posted every Monday.

Wireless connectivity outside of cellular has been around for almost 20 years and new process technologies are pushing solutions toward high-performance and power-optimized architectures. Bluetooth Smart is one of the technologies riding the Internet of Things (IoT) wave, meaning it allows products to connect to the Internet. Bluetooth Smart uses Bluetooth low energy protocol that became part of the Bluetooth v4.0 standard in 2010. It operates on the 2.4 GHz ISM frequency band and provides a robust and secure wireless solution in a low power implementation. Security is an important aspect for wireless systems, especially when physical and mechanical behavior can be controlled, or if private information is transmitted. You would not want your insulin pump to be hijacked by a disgruntled neighbor, right? Or a less lethal example when another neighbor, the “comedian,” starts to flicker your lights and turning on your home appliances at midnight on Friday the 13th.  Don’t worry, Bluetooth Smart has a wide set of security features to prevent these scenarios:

  • Authorization, prevents data access from unknown devices
  • Integrity, ensures non-corrupted and reliable data transfer
  • Confidentiality, by 128bit Advanced Encryption Standard (AES)
  • Privacy, by using resolvable addresses and frequency hopping on 37 channels

Security is one of the more important parameters for Machine to Machine (M2M) applications. M2M is the concept of allowing devices to communicate with each other, either by cables or wirelessly. Traditionally, M2M networks have used wired-networking solutions. However, choosing a wireless protocol can be very beneficial in many aspects. The first is the cost, which is reduced by removing expensive cabling and simplifying the installation. The second is robustness where the complete wireless solution could be encapsulated and completely sealed off from water, dirt and other substances that might be harmful for the system. The third benefit is that moving parts are no longer a problem so mechanical design is simplified. Finally, adding a smartphone to the system, Bluetooth Smart allows firmware updates over the air and aids in predictive maintenance of systems through alerts before critical service is needed. On top of this, Bluetooth Smart adds the security already mentioned, which allows the communication to be private and reliable.

An M2M-enabled device could be any electrical product that has or needs data, or a device that a person would like to interact with. In your home, there are probably more than 10 devices that could benefit by having communication with your smartphone. One example would be a washing machine sending a notification when it is finished. Most smartphones on the market today are Bluetooth Smart Ready which means that they are compatible with any Bluetooth Smart device. 

The idea of communicating with a device through a smartphone can be segmented by the describing, and rather boring, name Remote Display. A smartphone is a remote display in the sense that it can get instant information from a physical device that often does not have a display in the surrounding area and present it to a user. And the surrounding area may be larger than you think. Bluetooth low energy was designed to be a Personal Area Network (PAN) with typical range of 10m. However, most Bluetooth Smart wireless MCUs these days can cover up to several hundred meters in line of sight. For a building environment though, regular walls could block the signal. That is no real threat as Bluetooth Core Specification v.4.1 (2014) introduced support for a new topology where a device can be master and slave simultaneously. This introduces new applications where Bluetooth Smart can operate more as a network, which can route information throughout a building. Increased link budget will also help with challenges in solutions for indoor environments. Anyhow, let’s get back to the remote display; and presume an example. For a service technician, the remote displays provide multiple advantages:

  • Use measurement tools (e.g. Multi meter or AC Meter) that can provide direct information to a smartphone, which is then sent directly to a cloud service for further processing or storage for future statistics.
  • Malfunctioning industrial machinery can be troubleshot from a safe distance. This is useful if the machine would be in an unknown state or straight out dangerous, or the technician is just being lazy.
  • Distribution of access can be maintained, so that you only allow certain service technicians access to the tools shed, or maintenance of machinery. This could keep clumsy technicians away from expensive gear as well.
  • Interactive guides on the smartphone can simplify debugging, or the technician could get guidelines on how to solve something in an efficient and safe manner.

Remote Display is an excellent example of why Bluetooth Smart is preferable choice for industrial applications that require maintenance and service in an easy and safe manner. Adding Bluetooth Smart to a product is much easier than you might think. It’s a matter of adding a small discrete design or a module of around 2cm2 that could be interfaced to sensors or other intelligent systems already residing within a product. This small module would be the Bluetooth Smart add-on to the product, which can communicate with all Bluetooth Smart Ready devices, which is more or less all smartphones and tablets, unless you are really unlucky. 

Stay tuned for part two of this series covering lighting applications and let me know what you think of using Bluetooth Smart as a remote display. What application would you connect to? What information would you track?