Bluetooth Low Energy (BLE), sometimes referred to as "Bluetooth Smart", is a light-weight subset of classic Bluetooth and was introduced as part of the Bluetooth 4.0 core specification. While there is some overlap with classic Bluetooth, BLE actually has a completely different lineage and was started by Nokia as an in-house project called 'Wibree' before being adopted by the Bluetooth SIG.

There are plenty of wireless protocols out there for engineers and product designers, but what makes BLE so interesting is that it's almost certainly the easiest way to design something that can talk to any modern mobile platform out there (iOS, Android, Windows phones, etc.), and particularly in the case of Apple devices it's the only HW design option that doesn't require you to jump through endless hoops to be able to legally market your product for iOS devices.

This guide will give you a quick overview of BLE, specifically how data is organized in Bluetooth Low Energy, and how devices advertise their presence so that you can connect to them and start passing data back and forth.

BLE Platform Support

Support for Bluetooth 4.0 and Bluetooth Low Energy (which is a subset of BT 4.0) is available on most major platforms as of the versions listed below:

• iOS5+ (iOS7+ preferred)
• Android 4.3+ (numerous bug fixes in 4.4+)
• Apple OS X 10.6+
  
• Windows 8 (XP, Vista and 7 only support Bluetooth 2.1)
  
• GNU/Linux Vanilla BlueZ 4.93+