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. This is the second blog of a 6-part series ECN Texas Instruments about the benefits of using BlueTooth Smart in industrial applications. The blogs will be posted every Monday.
Light sources are important. Did you know that there are professional interior designers that focus on composing the “right” light scenery in order to bring happiness and unconscious satisfaction into your home or work place? Lights can affect your mood and enhance it, or change it. A romantic evening will be enhanced with some warm red-ish lights whilst squirting a smooth light green palette on a wall beside your work desk might reduce stress. Bottom line, lights are important.
Light bulbs, as commercialized by Thomas Edison, have been used for more than a century in various models with evolving solutions electronically. We are now in a shift to digitalized LED light bulbs. The era of analog is bending over for the digital smart solutions. I will not dwell on the benefits of LED bulbs but rather focus on the next step, which is putting something intelligent into the light bulb.
Introducing digital embedded systems within the bulbs introduced opportunities to add connectivity as well. ZigBee® technology has successfully adopted this application by providing a wireless network topology allowing a gateway to control over hundreds of light sources at “once” through Internet access or connected light switches. The control includes switching, grouping and, if supported, color manipulation. This can be done with Bluetooth® Smart as well. In the time of writing this article, Bluetooth Smart is a star topology. This means that one master device (i.e. a smartphone) connects to multiple slaves (i.e. light bulbs), which is controlled separately. One benefit ZigBee has with the network topology is that nodes in the network can route information which allows control of devices that might be out of range for the gateway.
For this to work with Bluetooth Smart there must be a way to pass information from one slave device to another. It could be implemented by role switching, since Bluetooth v4.1 introduced the option for a device to simultaneously be master and slave. However, role switching might be an unnecessarily complex solution. Fortunately, Bluetooth Mesh is a feature that is being evaluated for Bluetooth low energy feature portfolio, which means that there soon might be a specification on how to implement a network topology in an efficient, robust and secure way. So would this threat the existing ZigBee solutions or could Bluetooth Smart coexist and add features to already deployed solutions.
I’d say yes, to both. If Bluetooth Mesh turns out to be much more intelligent and low power than ZigBee, it’s an evolutionary step to replace the technology for that specific use case. However, there are always pros and cons and it’s wise to already consider designs where Bluetooth Smart is added to ZigBee.
Bluetooth Smart could be added to an already deployed ZigBee solution by introducing a node (i.e. the light bulb) that implements both ZigBee and Bluetooth Smart. It would not really be beneficial to update the gateway for the solution as it already has smartphone connectivity through the cloud or direct communication using Wi-Fi®.
Texas Instruments is a provider of both ZigBee and Bluetooth solutions, so it’s very much in the interest to have an open mind to the evolution of wireless standards. Some might say that Bluetooth Mesh is a declaration of war to the ZigBee Alliance; I say it’s an inevitable evolution.
The concepts presented in this article can be extended to any existing industrial application. ZigBee is a well-known standard in a massive pool of wireless solutions including proprietary Sub-1 GHz up to the free 2.4 GHz band and beyond. Lighting is just one example of Bluetooth Smart working its ways into new applications that require robustness and secure operation. Bluetooth Smart has been branded as targeting consumer applications, but it’s definitely not limited to it.
If you are curious on implementing Bluetooth Smart in lighting or any industrial application, TI’s Bluetooth Smart CC2540T is a high temperature qualified wireless MCU with a fully featured Bluetooth low energy stack. There is also a light bulb reference design available at ti.com.
Filed Under: M2M (machine to machine)