This is an opensource watch framework. The same software can run in simulation (SDL) on linux, on pinetime and on the ds_d6 oled watch.
This sample reads/sets the time, using bluetooth CTS.
A bluetooth CTS server. This can be a smartphone.
Included is a python-script : gatt-cts-server.py, for use with bluez on linux.
python3 gatt-cts-server.py
you need to connect to the watch in order, to have it read the time.
bluetoothctl
scan on (gets you list of bluetoothdevices)
connect D5:A0:A2:6D:A0:D5 (pick the pinetime - macaddress)
west build -p -b native-posix_64 oswatch-cts