Bluetooth low energy – that Eureka moment
- Published
- in Wireless
One of the nice things about working in technology is those moments when everything clicks and you go “Wow – that’s neat”. It’s something that happens as you work with many of the different standards and you realise that the collective intelligence of those putting it together really is greater than the sum of the parts.
Over the years I’ve had that Eureka moment with a number of wireless standards. They don’t all have it. Wi-Fi doesn’t – it just does a good job of making Ethernet wireless. GSM has it in the unlikely form of SMS. Kevin Holley, who was probably more responsible for SMS than anyone else, should be given an award for that. ZigBee has it – it’s the moment you realise that within the network you’ve just configured, multiple devices can be having their own, independent wireless conversations at the same time.
Despite years of being involved with Bluetooth, I’ve not found it there. Bluetooth is very impressive in its thoroughness, but again, it’s good, competent specmanship, which does what it says on the box. What Bluetooth has done is to provide a solid base of knowledge for the development of the new Bluetooth low energy standard, which was adopted today. Over the last year I’ve been helping develop the standard and explaining it to designers and engineers around the world. During that process I’ve realised that it doesn’t have just one, but two of those Eureka moments. And it’s been obvious at the conferences I’ve been speaking at, that as soon as developers understand it, they share that excitement. These two features are the ability for a device to talk directly to a web application, and how easy it is to use.
Enabling Internet Connected Devices
The first Eureka moment centres around the way that Bluetooth low energy will enable the design of Internet Connected Devices. Today, if you want to make a device that has a wireless connection to the web it’s remarkably difficult. You can use Bluetooth to connect a device to a mobile phone. But you then need to load an application onto the phone that retrieves data from the device, processes it and then forwards it onto the appropriate IP address. As most Bluetooth devices connect using the serial port profile, which leaves the data protocol and data format up to the discretion of the manufacturer, it means that every device needs its own specific application to be loaded on the phone. And because there are so many different phone platforms, each with an incompatible operating system, you’ll need to write twenty or thirty different versions of this application. Not surprisingly, there aren’t many of these around.
Wi-Fi is not much easier, which may come as a surprise. The problem with making a self contained Wi-Fi product is that you need a pretty hefty processor to run the driver and TCP/IP stack. That pushes the component and development costs up. So what seems easy on a laptop, rapidly becomes a project that is heavy on both development cost and battery life. There are a few such devices around, of which my favourite is the Nabaztag rabbit. But it’s not something that really works with mobile, low cost devices, although a few companies are trying to change that with low power Wi-Fi chips. So Wi-Fi based Internet Connected Devices are few and far between.
Eureka Moment Number 1
Now for the first Bluetooth low energy Eureka moment. For the first time, a specification has looked at the entire ecosystem that is needed for a device to connect to a web application. It’s designed to spend most of its life asleep, so it can run on a coin cell for years. When it has something to say, because it’s measured something or someone’s pushed a button, it can send that snippet of information. Now comes the clever bit.
Every handset that supports Bluetooth low energy can have a generic gateway application loaded at manufacture. When a Bluetooth low energy device first connects to your phone, it can tell this application which IP address or website it would like to connect with. The gateway application opens a secure tunnel from the device to this address, and then sits aside while the web application configures the Bluetooth low energy device. After that, whenever the device has data to send, it informs the phone, which reopens the tunnel and allows the device to talk to its web application.
If you’ve not had the Eureka moment yet, let me explain the beauty of this approach. You don’t need to load anything onto your phone. Let me say that again – “You don’t need to load anything onto your phone.” If you go down to your local store and buy a Bluetooth low energy device, it will be able to connect to its website via your phone as soon as you turn it on. All you have to do is say “yes” when the phone asks if it’s OK to set up that connection. It means that every device will work with every phone.
Once designers get this, they start to look at the things around them with totally different eyes. Almost everything we own has some intrinsic piece of data. My chair knows my weight, my beer glass knows how much I’ve drunk, my tennis racket knows I’ve hit the ball (or missed it). Today none of these devices share that information. Bluetooth low energy makes it possible and it makes it cheap. To help designers start to think abut how devices can share their intrinsic data and turn it into a compelling application, the Bluetooth SIG has been running its Innovation World Cup to encourage them to come up with new ideas in the area of sports and fitness. The first results get announced next February – expect some exciting new product ideas.
Ease of Use – Eureka Moment Number 2
The second Eureka moment was one I’d not initially noticed, but dawned on me as I started to explain how Bluetooth low energy works to various groups of engineers. It’s the fact that it’s so easy to use.
With every other wireless standard you need to spend quite a lot of time understanding how the underlying standard works. That’s because they do a poor job of hiding their complexity. Instead they tend to let it creep up into their profiles, which become extremely difficult to use.
Bluetooth low energy has a much more streamlined structure, which integrates far more of the protocol and data formatting into the core standard. Instead of complex profiles, there is an object oriented set of features exposed by each device, which the application at the other end uses to set its behaviour.
The effect of this is that development times plummet from months to days. At the recent Bluetooth low energy conference in Beijing, Texas Instruments showed a video of a remote controlled toy car using their Bluetooth low energy chips. It demonstrated the excellent range of low energy (around 100 metres), but the thing that most impressed delegates was the development time. When planning the work, they’d initially though about the timescales they’d seen for other projects – around three months. With Bluetooth low energy it was days.
The availability of qualified chips should mean we should see development kits landing in the laps of designers early in the New Year. Bluetooth low energy is so easy to use that I think these will become a must-have for those Friday afternoon projects. And for the first time, engineers will be able to think of an application one evening and have a real chance of having a demo working by the following evening. That will change the way we design all sorts of products. And it’s enough to make anyone jump out of the bath.
Someone once labelled me a technology optimist and this probably proves the point, but even I didn’t think it would take this long. The good news is that Apple is finally shipping products with a Bluetooth LE stack and an open interface, so I’m hoping to see applications take off.
I blame a lot of the delay to the misunderstanding about Bluetooth low energy and the attempts within the SIG to shoehorn it into the old Bluetooth profile model. What people like Apple and BlueGiga have done is to understand the power of having an open GATT interface where designers can develop their own profiles.
My hope is that they will make these public, as I’ve always believed that the development community is a far better place to develop GATT based profiles than within the SIG. And I hope it won’t take another three and a half years for that to happen.
Nick
Now 3.5 years later… Where are those gateway apps? And when would we expect to see that function as part of the mobile OS?
Thanks for the kind words about me! Great article too!
Kevin
Hi Nick
Really love this article about LP BT.
I also love the Nabaztag – my kids play with one we have at home. It’s not quite the kid-friendly experiment I was hoping for, but food for thought. We enabled some feature that causes it to send us random voice messages from some curious chap with very weird aphorisms.
Cheers
Paul G