BT Smart Comes Of Age


For those wanting to develop peripherals with BT Smart (previously known as Bluetooth Low Energy or BLE), the options so far have been limited. Either, work directly with chip manufacturers like TI or use a module such as the excellent BLE112 (based on the TI chipset) from Bluegiga. Chipsets give the benefits of low component cost, but require high volumes to be used to make the development and approval costs worthwhile. Modules however, are normally pre-approved, but come with a higher price tag. Typical component costs for a solution in volume would be in the order of $4 or $15 respectively.

BT Smart of course, is the new ‘version’ of Bluetooth that actually has nothing in common with traditional Bluetooth, but allows for devices to run at very low power, able to run off of coin cells for years. They also require less overhead in an operating system, typically within iOS for example, being able to connect directly from an app, rather than having to go ‘techie’ to connect a remote device. More than one device can be connected at a time, too.

Bluegiga's BLE development Board

Bluegiga’s BLE development Board

Bluegiga’s great feature is the fact that an application can reside on the BT Smart device, allowing it to run autonomously, too. Basically access is given to the processor on the device, and Bluegiga have developed a neat scripting language to enable these apps to be implemented on their devices.

Just a couple of weeks ago, Bluegiga sold their business to SiLabs, we have yet to see what will happen as SiLabs absorb the Bluegiga business and IP, how much of Bluegiga’s innovation will continue, too.

But, almost at the same time, a new pretender to the throne has arrived. Anaren, with a Broadcom based module. Pre-certified too, this comes in at a much lower price tag. Developers working with the BLE112 will find it difficult to justify staying with that solution with Anaren’s similarly featured A20737 device coming in at around a THIRD of the price of the Bluegiga module.

Anaren's BT Smart development board

Anaren’s BT Smart development board

Demonstration apps are simple to develop, with their online ‘Atmosphere’ development environment meaning that it is platform independent, no development tools have to be installed. Bluegiga on the other hand only support the PC for their script compiler, a slight disadvantage now given that most silicon vendors support Mac and often Linux too, with their tools. It’s fast too, I got my first app running and communicating from iOS to BT Smart device in about thirty minutes flat. That’s impressive.

Anaren provide a visual development environment, allowing a developer to quickly prototype an application and demonstrate it, with connectivity to iOS and Android supported. What is unclear, and remains to be seen, is how simple this is to move to production. The programs that go onto the BT SMART module and the phone are not clearly delineated. GATT profiles are not clearly published from Atmosphere, with some rather vague explanation in their support Wiki pages (I’m sure this will be improved with time). Certainly, all of the communication between host and target goes through in one large GATT characteristic (called “Atmosphere Transport Protocol”, not really the best implementation or optimised for low-power applications.

So, Atmosphere does seem like a bit of a blind alley. Great for concept proving, but not really much use to move onto production. But, help is at hand. The module, being based on Broadcom’s BCM20737 device is supported by their ‘Wiced’ (pronounced ‘wicked’) development tools. An Eclipse IDE and the compilers are all free to download for PC or Mac, and allow development in ‘C’. Example frameworks are supplied, I haven’t developed anything just yet, but they look fairly straightforward to use, and you can see the commonality carried over into Atmosphere, so if you use that first, it should be easier to move onto the Broadcom tools. Time will tell how simple it is, but it’s certainly worth investing a little time, given the difference in price with the modules. It’s really not worth moving to a BT Smart chipset unless you are using really high volumes, probably in excess of 200K units or more, I would think.

It does look like Anaren have hit the mark with this device, and likely that Bluegiga have sold their business at just the right time!

I’ll post more as I learn more, I have an active BT Smart project right now that is running on Bluegiga already and is being ported to Anaren before production.

Prices of the development kits? Bluegiga’s is around $200, Anaren weigh in at about $50, software tools for both are free.


The Pebble Watch

Pebble watches in different  colours

Pebble watches in different colours

I’d been looking at the Pebble Watch for a while after buying one as a gift for a friend. It had been available in the retail channel in the UK for a couple of months. After receiving mine for Christmas, I set about writing an App for it to function as a Rugby timer and scorekeeper.

I’m pretty impressed with the watch overall. If you have a program like this that is useful to you, it’s going to be worth having for that alone. Other watches might be prettier and offer more functions, but (I’m pretty sure) that most are limited to working with one watch OS alone. Android watches need an Android phone, and so far, I think the Pebble is the only watch to work with iOS. It’s not sold in the Apple store of course, it’s a competitor to the forthcoming Apple Watch, but they will continue to hit different markets as the Apple Watch is likely to be at least twice the price of the Pebble.

The watch is unpretentious. It doesn’t claim to be the most powerful or best smart watch out there. It has a mono screen, not colour like most of the others, so it’s not flashy at all. What that gives the watch though, is an advantage in terms of battery life. They claim 5-7 days in normal use. You charge it using a magnetic cable that takes power from a USB port, so you can charge from your computer or a wall adapter, and it only takes a couple of hours for a full charge.

It’s an “e-ink” display, this is the sort that doesn’t really take any power if it doesn’t change. So, if your watch face changes every second as opposed to every minute, then it will drain the battery a bit faster.

Watch face with weather display

Watch face with weather display

My favourite watch face is a simple watch with the day and date as well as an outside temperature reading. This of course, comes from a data service that comes via the internet. Like all smart watches, access to the internet is via your phone – connected via Bluetooth – so, if your phone isn’t available these sources of data (there’s also some selectable watch faces with news and so on,) are not available either.

This watch face also shows your current location, there are others that even show a little map on the display.

Hardware wise, the watch has an accelerometer and compass, so can function as a basic fitness tracker, there are apps for that too. An impressive compass display is another. It has standard Bluetooth and Bluetooth SMART, so this probably helps the battery life somewhat. I’m not sure what data is transmitted via Bluetooth SMART, but it would make sense for things like the temperature data to go via Bluetooth SMART. It’s fully water-resistant too – that’ll be handy for those rainy Saturday afternoons on the touchline!

Built in is a music controller (AVRCP) so you can play/pause forward/reverse music on your phone.

Rugby timer & scorekeeper app

Rugby timer & scorekeeper app

Watch faces and apps are downloadable from the ‘Pebble Store’. At the moment, all of the apps are free, so you can download what you like, but a few developers use what are called ‘companion apps’ which the watch app will require to operate. They then charge for these apps via Google Play or Apple’s App Store, so they get paid that way. That said, most are free. Up to eight apps and faces can be stored in the watch, a ‘locker’ in your phone is used as an overflow for others, so they are quickly available to you. Watch faces range from digital displays with big numbers, words and analogue displays.

I got the basic watch, there are two models, the Pebble Watch (£99) and the Steel (£179). The Pebble Watch is a clunky looking, plastic affair available in different colours – most will opt for black like me, I would imagine. The Steel is a more robust looking and probably more conventional looking watch. The standard watch comes with a rubber strap, which I quickly replaced with a leather watch strap from my local jeweller. I got a decent quality Hirsch strap, but any 22mm strap or bracelet will work. The steel has a non-standard fitting, so you’ll need to buy a strap or bracelet designed for that watch.

For developers, the development tools are very straightforward. You don’t even need to install anything on your computer, you can develop and compile using ‘C’ via CloudPebble – an online development portal. Publishing a finished app is simple too, your app goes straight into the store. By comparison, iOS development is much more complex and the approval process to get into the store is much more long-winded. But then, Pebble is a simpler concept from the start. You can install a compiler onto your computer if you want to be able to develop off-line, OS X, Linux and Windows are all supported.

Pros and cons? Well, price, battery life, simplicity and iOS compatibility are things this watch have going for it. Lack of a colour display and possibly the clunky looks might be things that will put you off.

When the Apple Watch arrives, this might change things, but we will see. Apple have done some really clever things with the watch bracelets and straps, making them easily interchangeable without tools. In all the years the jewellery industry have been making watches, they haven’t done anything as clever as Apple have with their straps! Apple Watch might be a game changer, but I’ll still be using my Pebble as a rugby timer on Saturdays at least, I’m sure.

A New Wireless Camera Controller


Update 18th July – the second prototype

For a couple of weeks now, I’ve been working on a new camera controller.

Like many photographers, I often use a cable release to activate the camera. This has a number of advantages in allowing the camera to remain steady on a tripod, or simply to allow me to look over the camera while shooting. More recently, I’ve been using a radio remote controller which has the same simple shutter release control, but is wireless.

I’ve been involved in Bluetooth technology for some years now, and a new development is Bluetooth SMART – also known as Bluetooth Low Energy and included in the Bluetooth 4.0 standard that is appearing in mobile phones, tablets and computers now.

Bluetooth SMART is a very low power protocol, designed for low-data throughput devices such as temperature sensors, switches etc., and it lends itself quite well to the camera controller function I mentioned. Devices will run from a
coin cell for years – unusual for a wireless device.

So, I set about developing such a device, but rather than just have simple shutter control, I have added timer functionality.

You can trigger the device and take a single shot, just like a normal radio remote, but you can also set parameters that allow you to start a timer running which will wait for a period of time, then take a number of shots at a programmed interval. Once the parameters are set and the timer started it will run autonomously. Range is about 100 metres, so it’s a very useful remote trigger too.

All of this can be triggered and controlled from any Bluetooth 4.0 capable device, such as the iPhone 4S, iPad 3, most new Mac computers and newer PCs. Most new devices include Bluetooth 4.0, so expect to see many more in the coming months.

The prototype is all working, with a program in the device to give this functionality. The next steps are to produce a PCB (printed circuit board) to allow these to be made in higher volume – and neater – rather than like the hand-built prototype above. I also need to develop iOS and Android apps that will allow the device to be controlled from smartphones. This can be done at the moment, but via a rather clumsy generic Bluetooth application on these phones.

Bluetooth SMART Controller Prototype

I reckon the device could be made available in the retail market at £50, with the iOS app being a free download. Different versions to connect to Canon, Nikon, Sony cameras would be available (a different connector is needed for each manufacturer) and the controller is your phone – which you have with you, rather than a second box for the trigger.

So how to do the next steps? Design the PCB myself, design the iOS app? both of these are new to me, but I know people who could do this. Maybe use Kickstarter to finance the project? Not sure.

Watch a demonstration of the controller here:

But, I am looking to move this forward – if you have any bright ideas, let me know!

23rd July – added datasheet – Phooto iSMART Datasheet

27th July – new video with the second prototype controller –

2nd August – If you would like to make one of these, let me know, I can provide the circuit diagram and object code to load into the Bluegiga BLE112 used here. You will need to source the module and components. I would be interested to get feedback on the device – you might even be interested in developing iOS software for it?

Blexplr iOS program used to control the timer

6th August – Dr Michael Kroll’s ‘Blexplr‘ program has been invaluable in developing this application – and has now been updated with the UUIDs to support the device. (see picture).

19th August – First Nikon D90 version made.