Hi Daniel, I hope you're doing well!
There's three different OTA SDK examples available within the package, each implementing different functionality:
The two OTAP Client examples each implement different OTAP transfer methods, either using ATT or L2CAP CoC, and the OTAP Server example opens a connection from the board to a PC, and essentially works as a middleman between the Test Tool running in the computer and the OTAP Client device.
Depending on the transfer method that's going to be implemented, the receiving OTAP Client device should be programmed with the corresponding example.
As for the OTAP Server, the Test Tool has some configurations available to change settings such as transfer speed and method.
The current implementation allows the OTAP Server device to be connected to only one peripheral device at a given time, established by the way it was coded, and the following macro definition:
#define gAppMaxConnections_c 1
Thus, updating 4 devices at once would require considerable modification of the OTAP Server SDK example.
The Test Tool is available to download from our website here.
More detailed information about the OTAP example applications can be found in chapter 5.19 of the BLE Demo Applications User Guide, included in the SDK package in the following path:
<…\SDK_2.2.2_FRDM-KW36 - MCUXpresso\docs\wireless\Bluetooth\Bluetooth Low Energy Demo Applications User Guide.pdf>
Please let me know if you need any other information.
Best regards,
Sebastian