Product Specs

Page 6 of 18

 Central vs. Peripheral: The peripheral device has valuable information to

share with central devices. The central device treats the received data to fulfill

specific tasks.

Figure 1.

Figure 1 is giving an overview of the different roles, so what is the difference between

a client and a server? First let me remind you that a client and a server is not

interchangeable with master/slave.

Figure 2.

Standard Bluetooth LE peripherals broadcast their presents in order to be found by

centrals like smartphone’s and tablets, see Figure 2. The E-RL 2 is no exception to

this, when not connected by a central its broadcasting its presents so other centrals can

find it during a scan and make a connection if the peripheral allows connections that is.

Apart from the higher power consumption this introduces a security risk for some

product like bicycle locks, thieves will be able to locate bicycles in garages and/or

sheds by simply using one of the many freely available Bluetooth LE scanner/localizer

apps for smartphones. In order to overcome this kind of problems and to extend the

battery lifespan the BLE E-RL 2 has the option to activate a smart sleeping

mechanism, during a sleeping period it’s not broadcasting and undetectable even for

the bicycle owner’s app.