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 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.
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.