2 Bluetooth Low Energy Basic Knowledge

According to the Bluetooth Low Energy Core Specification, there are two roles defined (GAPRoles) when the Bluetooth Low Energy connection is established. The node that initiates the connection defined as the Central device and the node that is connected to by the Central is defined as the Peripheral device.

There are several parameters that are important for the Bluetooth Low Energy connection, two of them are connection interval and slave latency. The connection interval determines how often the central asks for data from the peripheral. The slave latency represents the number of times the peripheral can choose not to answer when the central asks for data. The connection interval and slave latency typically affect the performance of a Bluetooth Low Energy link the most. For example, the lower the slave latency and faster the connection interval, the faster the effective data transfer rate between the peripheral and central. On the other hand, this also leads to a higher average current consumption since the devices use their radio more often than at a longer connection interval.