We are using Screenly and a Raspberry Pi 3 Model B for digital signage. I see from the documentation that this is running on Raspberry Light version of Linux. Due to the web interface for Screenly, we have decided to use a static IP address's/ I have a background with other Unix products my experience with Linux is limited. We will mount the Pi behind a display. The display is on the first floor, the network closet is on the second floor some distance from where the display is hung. We will set up the Pi to use the wireless interface for now while we wait for the cable to be run. Once the cable is installed the Pi will be wired to the Church network. The Pi and the display will be moved from time to time to be used for various events, etc. In those times it should use the wireless LAN again.
My goal is to configure the Pi to use the WLAN interface if there is no ethernet cable connected. When an ethernet cable is connected the Pi should disable(?) the wlan interface and use the eth interface. I am referring to wlan0 and eth0. I have found instructions on configuring both with static IP addresses and have those address. I understand that it will be best to have a different address for each interface. I am not sure if it is possible to disable the wlan0 interface based on the status of the eth0 interface. Thanks for your help on this.