Is the question about the lightness and color temperature or a step motor :-). For the Light CTL model, See apps/snip/mesh/mesh_light_ctl_server.c, the call is
wiced_bt_mesh_model_light_ctl_server_state_changed(...);
Note that your device needs to be configured for Publication to send unsolicited messages.
For the step motor, unfortunately there is no standard model. You can use Vendor Specific model and send whatever messages you need.
Note that you should be pretty careful with mesh messages, because the bandwidth is very limited. If your application does not need to send messages, do not send them. If phone UI does not require update more than once per second, configure your step motor to publish data once per second. You can also configure for publication when entering the screen and unconfigure when exiting the screen.
