Logitech G815 Shortcut Helper

I wrote a small shortcut helper in GoLang that helps me to remember the most useful shortcuts for IntelliJ based products tested with Rider and GoLand and a QWERTZ keyboard.

Intro

I recently bought a Logitech G815 which turned out to be a great decision for multiple reasons. The obvious one being that it's a great keyboard ✨. The other one is that I found out Logitech provides an SDK for the keyboard => 👌.

RGB Keys

The keyboard supports RGB background lighting for each key. There are plenty of integrated functions such as a color wave which looks great🌟. The keyboard is made for gaming purposes and yes it does integrate with a lot of games but I didn't try any myself🙈.

SDK

The Logitech SDK can be found on this website: https://www.logitechg.com/en-us/innovation/developer-lab.html.

I was particularly interested in the LED Illumination SDK.

The SKD is written in C++ and provides the .lib, .h, .dll, and some examples and is windows only.

Integration with GO

I'm currently learning GoLang and I wanted to program this in go and not in C++ or C#.

Calling native C++ functions from GO

I found a great way to call native C++ functions from Go using the sys module.

Original repo: https://github.com/golang/go/wiki/WindowsDLLs

type LogiKeyboard struct {
    dll                             *windows.LazyDLL
    ledInit                         *windows.LazyProc
    // ...
}

func Create() *LogiKeyboard {
    p := new(LogiKeyboard)

    // initialization of the dll
    p.dll = windows.NewLazyDLL("LogitechLedEnginesWrapper.dll")

    // assign the function
    p.ledInit = p.dll.NewProc("LogiLedInit")
    //...
    return p
}

// wrapper for the init function
func (v LogiKeyboard) Init() {
    ret, _, _ := v.ledInit.Call()

    if ret != 1 {
        log.Fatal("Already initialized")
    }
}

Additionally, I had to translate the .h file in go syntax. This helps to have all the constants (like defines) in one place and reduce code duplication. Here is the file.

Integration with Windows

I needed a slim and easy way to catch Windows keystrokes. Turns out there is a great module for that as well: github.com/moutend/go-hook.

main.go:

if err := run(shortcuts); err != nil {
    log.Fatal(err)
}

func run(shortcuts []Shortcuts.Shortcut) error {
    // Buffer size is depends on your need. The 100 is placeholder value.
    keyboardChan := make(chan types.KeyboardEvent, 100)
    if err := keyboard.Install(nil, keyboardChan); err != nil {
        return err
    }

    signalChan := make(chan os.Signal, 1)
    signal.Notify(signalChan, os.Interrupt)
    for {
        select {
        case <-time.After(5 * time.Minute):
            fmt.Println("Received timeout signal")
            return nil
        case <-signalChan:
            fmt.Println("Received shutdown signal")
            return nil
        case k := <-keyboardChan:
            // check if shortcut modifiers are pressed and set RGB color
        }
        continue
    }
}

Those few lines of code are everything you need to create a keylogger in go. Isn't that crazy?

Shortcuts

Shortcuts can be modified in main.go:

var shortcuts = []Shortcuts.Shortcut{
    // if the left shift key is presed:
    // F6 will start blinking red
    // F9 will change the color to blue
    Shortcuts.CreateWithKey([]types.VKCode{types.VK_LSHIFT}, []Shortcuts.ShortcutKey{
        Shortcuts.CreateKeyColorEffect(LogiKeyboardTypes.F6, 100, 0, 0, Shortcuts.Blinking),
        Shortcuts.CreateKeyColor(LogiKeyboardTypes.F9, 0, 0, 100),
    }),
    //...
    }

Integration with Logitech GHub

The keyboard has five G keys and each key can be assigned with a different task. One task is to launch an application => great :). The downside of this function is that an application can be started but not stopped. I wanted to start and stop the shortcut helper with the same key just like a toggle.

As always there is a workaround in PowerShell😂:

Set-Location -Path C:\Projects\LogitechKeyboardLED

$ProcessActive = (Get-Process logitechKeyboardLed -ErrorAction SilentlyContinue).Id
if($null -eq $ProcessActive)
{
    Start-Process ./logitechKeyboardLed.exe -NoNewWindow
}
else
{
    Stop-Process $ProcessActive
}

Configure the G key using the Launch Application option:

Shortcuthelper in action

Github Repo

Thanks for reading :)