Bluetooth began as a way of providing a consistent wireless interface between mobile phones from different manufacturers and third-party peripherals, such as car kits. It has succeeded phenomenally in that capacity and these days we can now rely on Bluetooth to interconnect all sorts of consumer devices. In 2010, seeing the success of Bluetooth technology and the advent of the Internet of Things (IoT), the Bluetooth 4.0 standard introduced Bluetooth Low Energy (BLE), also known as Bluetooth Smart, as an additional, power efficient protocol.
While classic Bluetooth technology has transformed our consumer electronics, making it easy to wirelessly connect keyboards and mice to our computers, and listen to music without messy wires, Bluetooth Low Energy promises to transform other markets too.
Industrial Strength Connections
Bluetooth Low Energy’s smartphone ubiquity, power efficiency, and robust connectivity, make it a great fit for connecting devices in medical and industrial applications.
Device compatibility is unrivalled. As part of the Bluetooth standard, BLE has nearly universal support on consumer devices made in the last few years. Connections can be made directly between devices and smartphones, tablets or laptop computers, without needing routers, gateways, or proprietary wireless adapters.
It’s also extremely power efficient, especially for IoT devices. Whereas Bluetooth Classic was made to stream data, Bluetooth Low Energy has been optimised for transferring data in short bursts. It’s peak current usage is just 15mA, and its average consumption much less, as the protocol is designed to let devices spend most of the time in sleep mode.
BLE devices don’t have to support Bluetooth Classic – they can be “single-mode” – meaning they support BLE only. The BLE stack is very lightweight and the protocol is less resource intensive than Wi-Fi or even Bluetooth Classic. This allows BLE to be integrated into even the most resource-constrained embedded systems.
Finally, it uses frequency hopping which lets it coexist with other wireless protocols, such as Wi-Fi, in the 2.4GHz range. This lets it work in noisy RF environments, such as hospitals, or factories.
Medical Connectivity and More
The value of the IoT arises when data from sensors and readers is transferred to centralised devices and the cloud, where data fusion and analysis can take place more readily. Because of its ubiquitous nature, power efficiency and robust communication, Bluetooth Low Energy is the perfect way to get the data from devices like medical wearables or barcode scanners to the end user’s laptop or tablet for further processing.
BLE can also be used to extend the touchscreen interface of a smartphone or tablet to devices which may not have the computing power or display to support it otherwise. With a BLE connection, factory workers can monitor and control stationary factory equipment through a rich graphical experience on their tablet or smartphone, without being tethered to the machine. Unlike Wi-Fi, Zigbee or other wireless protocols, the connection is extremely power efficient and no external routers or adapters are required, just BLE support on both devices.
Easing BLE Development with SmartBASIC
Developing BLE embedded applications has traditionally been an involved, low level process, involving wading through the lengthy BLE specification, as well as vendor specific documentation, and coding in low level, hardware specific C. New BLE modules from Laird Technology are cutting the BLE learning curve and making the development process much easier by supporting SmartBASIC programming.
Developed by Laird, SmartBASIC is an event-driven programming language based on BASIC, used to program embedded BLE applications. It has the simple, easy to understand syntax of BASIC, but uses modern structural programming language constructs such as subroutines, functions, loops and conditionals. As an event driven programming language, SmartBASIC is made for the event-driven nature of BLE interactions, making it easy to create power efficient applications which maximise device sleep time.
Rather than interfacing directly with low-level hardware, SmartBASIC exposes BLE stack and device functionality through a high level API. Through SmartBASIC, developers have access to BLE advertising, connection, security, status, and power management functions. Engineers new to BLE development can leverage the built-in functions, which replace hundreds of lines of C code to quickly create easy to read programs.
Figure 1. BL600 and BL620 BLE smartBASIC modules.
The BL600 (peripheral) and BL620 (peripheral or central) modules from Laird are compact BLE Modules able to run smartBASIC in live, interpreted mode, or in run-time mode, where program code is compiled to bytecode and run from the module’s on-board flash memory. Since the modules are pre-qualified as Bluetooth End Products, designers can easily integrate these modules into their products without need for further Bluetooth Qualification.