central , server master vs peripheral, client, slave

[ToTo]

Hi When using BLE events i'm usually confused which event to handle , for example GATTS_WRITE or GATTC_WRITE.. i don't know which is the server and the client ?

Any idea to differenciate between them ? I tested some apps and i read some documents ,, i arrived to this conclusion : MASTER=Server= Central Slave=Client=peripheral Is that True ?

[Sensors]

What you're talking about is two different sets of roles really...

GAP roles: Devices are either a Central (master) or a Peripheral (slave).

Centrals initiate the connections to the Peripherals. For example, your phone may act as a central to a bluetooth speaker (it initiates the bond).

GATT roles: Devices are Clients or Servers.

Clients are the users of the connected devices, who act as the servers. i.e. a bluetooth sensor (server)would serve data to the connect phone (client).

Here's a good page with more explanation: punchthrough.com/.../

And another related post: devzone.nordicsemi.com/.../