KVM_Switch/README.md

Internal KVM Switch

FastAPI dashboard and polling service for Alienware-only KVM switching.

Trigger Logic

The Samsung monitor is trigger-only and uses fixed input codes:

• Tower trigger: 15
• Laptop trigger: 19

Each installation of this tool is for one device only. The UI lets you choose:

• this device role: tower or laptop

• this device Alienware target port:

• DP1

• DP2

• HDMI

The device role can also still be provided by:

• environment variable KVM_DEVICE_ROLE
• or config.json field device_role

Valid values are:

• tower
• laptop

Examples:

• Tower role with UI port DP1 -> on Samsung trigger 15, send DDM.exe /1:WriteActiveInput DP1
• Laptop role with UI port DP2 -> on Samsung trigger 19, send DDM.exe /1:WriteActiveInput DP2

Retry behavior:

• Only attempts switching while the Samsung screen is connected
• After each switch attempt, waits 5 seconds and rechecks
• Tries at most 3 times per Samsung-connected session
• After success, it will not try again until the Samsung screen disconnects and reconnects

Run

uv run kvm-switch

The dashboard is served at http://localhost:4000.

Test

uv run pytest -q

Diagnostic Script

Use this to inspect connected DDC/CI monitors and current input values:

uv run monitorcontrol_main.py

Autostart

Easiest option: Startup folder

You can now set the role in the UI, so this step is optional.

If you prefer a default role before opening the dashboard, set it for that Windows user:

Tower machine:

[System.Environment]::SetEnvironmentVariable("KVM_DEVICE_ROLE", "tower", "User")

Laptop machine:

[System.Environment]::SetEnvironmentVariable("KVM_DEVICE_ROLE", "laptop", "User")

1. Press Win + R
2. Run:

shell:startup

3. Create a shortcut in that folder pointing to:

C:\Users\LagoWorkStation\OneDrive\Documentos\BE-terna\Internal - KVM Switch\start_kvm_switch.cmd

This will start the app when you log in. It opens a console window.

Cleaner option: Task Scheduler

Use Task Scheduler if you want it to start automatically at logon with better control.

Program/script:

cmd.exe

Arguments:

/c "C:\Users\LagoWorkStation\OneDrive\Documentos\BE-terna\Internal - KVM Switch\start_kvm_switch.cmd"

Set the trigger to At log on.