On a linux box with bluez installed, a python script is launched (example-gatt-server)
The linuxbox becomes a bluetooth gatt server.
This script offers a service and a bluetooth characteristic. (the battery service is used for this purpose)
In the python script example-gatt-server 10 bytes of data are advertised (battery service).
The watch scans for this characteristic, once it is connected and reads out the variables and puts them in a 10 byte arry.
Hence a transfer from the server to the watch took place!
Later on we can use this to set a timer in the watch or an alarm, or ….
You’ll need to:
* run Bluez,
* start the script,
* and then connect to the watch, using bluetoothctl.
The mechanism is the same as with the CTS time setting.
BlueZ running on the host, or
A board with BLE support
See bluetooth samples section for details.