Gatt or gap?

[Nils Minor]

Hi ,

i read tha the default profile for BLE is GATT but in the BLE_templete GAP is used. How can i interpret this? Which Profile i have to use when i wannt support for IOS and android ?

Best regards Nils :)

[Pål Håland]

Hi Nils,

There are two mandatory services for Bluetooth Low Energy, one is GAP (Device Name, Appearance and optionally Peripheral Preferred Connection Parameters) and another one is GATT (Service Changed).

This is the reason why the BLE template uses the gap_params_init, to set up the device name and appearance characteristic + the ppcp.

You don't have to do it to make your profile work, but the device name that is stored by default in the chip is nRF51822 if I recall it correctly.

You can add services and profiles as you like, and it should still work with iOS and Android, depending on what your application on those devices is looking for.

[Nils Minor]

Hi, thank you for the answer. So in am i right, in the temlplate i use GAP and GATT? What means ppcp?

best regards Nils

[Pål Håland]

Yes, GAP and GATT would exist in every device, thus the initialization of it is added in the template.

PPCP is Peripheral Preferred Connection Parameters and is a way to indicate to the master what connection interval it would like to use without sending the connection parameter update request. The Master could read this parameter and update the connection interval accordingly.