BLE

BLE (Bluetooth Low Energy) is a standard which allows devices to share 'small' amounts of information over short range. BLE is not compatible with traditional Bluetooth. This article should provide you with just enough of an understanding of how BLE works to understand how it is used for the August lock. A more detailed description of BLE and how it works can be found here.

BLE communications involve a device running in 'central' and one in 'peripheral'. Generally speaking the central device will be a computer or a phone and the peripheral will be just that, a peripheral. BLE peripherals have services. These services are just sets of characteristics. Characteristics can be thought of as attributes which can be written, read, or that can notify (indicate) you when they change. However, not all characteristics support all of these operations. August uses characteristics that support writing to allow you to send messages to their locks, they use characteristics supporting indicate to send messages from the lock to your phone. The end result is you phone can raise events on the lock by writing to a characteristic, and the lock can raise events on your phone by notifying it of a change in value.

August locks have two bidirectional event channels called MCU, and SEC. The MCU channel is used to control the lock and various setting which affect how the lock behaves. The SEC channel manages the security of the lock and is responsible for managing encryption keys, and establishing the session key used to secure communication between the lock and phone.