LGTVDeviceListener: switch LGTV inputs based on Windows device changes

Brought to you by Etienne Dechamps - GitHub

If you are looking for executables, see the GitHub releases page.

Description

LGTVDeviceListener is a small Windows tool that makes it possible to switch inputs on a networked WebOS LG TV (e.g. G1), in response to a hardware device appearing or disappearing from the system.

This is especially useful to build a poor man's KVM switch, by combining LGTVDeviceListener with a USB switch. In this way the TV can be made to follow the presence of the USB device and automatically switch video inputs in lockstep when the USB device is switched.

Requirements

• Windows Vista or greater
• A WebOS LG TV that is accessible over the network (wired or WiFi)

How to use

LGTVDeviceListener is a command-line application. Pass --help to see all available options.

Preparation

After downloading the executable, run it with --url first. For example, if your TV is listening on 192.168.42.42:

LGTVDeviceListener.exe --url wss://192.168.42.42:3001

This will do two things:

1. A new client key will be registered with the TV if not done already. Your TV will ask you to confirm the registration.
2. LGTVDeviceListener will then start listening for device events and log them to the console.

While listening, add and remove the device you want to use as the trigger. (For example, if it's a USB device, disconnect/reconnect it.) You will see LGTVDeviceListener logging "Device added" and "Device removed" events. Take a note of the device name - the identifier that normally starts with \\?\.

In some cases there could be many devices shown, especially for composite devices such as USB hubs. In that case you can pick one at random, though it usually makes the most sense to use the device with the shortest name because that's typically the "root" device (i.e. the hub itself in the case of a USB hub).

Once that's done, kill LGTVDeviceListener by hitting CTRL+C and move on to the next step.

Running as a console application

For quick test runs you can run LGTVDeviceListener directly as a console application. You will need to specify the following parameters on the command line:

• --url: see previous section.
• --device-name: the device name you chose in the previous section.
• --add-input: the input that the TV should switch to when the device is added.
  • This can be anything that the TV's switchInput API will accept. For example: HDMI_3.
• --remove-input: the input that the TV should switch to when the device is removed.

Note that you don't have to specify both --add-input and --remove-input - it is possible to specify only one of them.

Here's an example of a complete LGTVDeviceListener command line:

LGTVDeviceListener.exe --url wss://192.168.42.42:3001 --device-name \\?\USB#VID_1234&PID_5678#foo&1&2#{bar} --add-input HDMI_1 --remove-input HDMI_2

With the above command, the TV at 192.168.42.42 will be switched to the HDMI 1 input when the \\?\USB#VID_1234&PID_5678#foo&1&2#{bar} device appears, and will be switched to the HDMI 2 input as soon as the same device disappears from the system.

This will happen for as long as LGTVDeviceListener is running. If you'd like to make this setup permanent, see the next section.

Running as a Windows service

If you'd like LGTVDeviceListener to run quietly in the background without having to run it as a console application, the cleanest way is to set it up as a Windows service:

1. Move LGTVDeviceListener.exe to a permanent location that is accessible system-wide (e.g. in Program Files (x86)).
2. Open a command prompt as Administrator.
3. Run LGTVDeviceListener using the same command you used in the previous section, but add the --create-service option.

For example:

LGTVDeviceListener.exe --url wss://192.168.42.42:3001 --device-name \\?\USB#VID_1234&PID_5678#foo&1&2#{bar} --add-input HDMI_1 --remove-input HDMI_2 --create-service

LGTVDeviceListener will set itself up as a new Windows service called LGTVDeviceListener and start it. From this point on, LGTVDeviceListener will be operating silently in the background and will start with Windows. The parameters used for the service are the ones you included with the --create-service command.

When running as a service, messages that are normally logged to the console, including any errors, will be logged to the Windows Event Log (Application) instead. You can use the Windows Event Viewer to see them.

To delete the service, run the following commands:

sc.exe stop LGTVDeviceListener
sc.exe delete LGTVDeviceListener

You can then re-create the service with different command-line parameters if you so wish.

See also

• LGTVCompanion is a tool for automatically turning LG TVs on and off in response to Windows power events.
• bscpylgtv can be used to send arbitrary commands to LG TVs.