# KVM Switch: Mac ↔ Nobara

## Hardware

- **Monitor:** Dell U3821DW (USB-C to Mac, HDMI 2 to Nobara)
- **Keyboard:** Logitech MX Keys S
- **Mouse:** Logitech MX Master 4
- **Bolt #1:** Connected to Nobara (Channel 2)
- **Bolt #2:** Connected to Mac via monitor USB hub (Channel 3)

## Switching Behavior

| Direction | Monitor | Peripherals |
|-----------|---------|-------------|
| Nobara → Mac | Auto (DDC) | Auto (HID++) |
| Mac → Nobara | Auto (DDC) | Manual Easy-Switch |

## Channel Setup

| Channel | Connection | Computer |
|---------|------------|----------|
| 2 | Bolt #1 | Nobara |
| 3 | Bolt #2 | Mac |

---

## Nobara Setup

### 1. Install dependencies
```bash
sudo dnf install ddcutil
sudo usermod -aG i2c $USER
# Reboot required for i2c group
```

### 2. Install hidapitester
```bash
mkdir -p ~/bin
curl -sL https://github.com/todbot/hidapitester/releases/latest/download/hidapitester-linux-amd64.zip -o /tmp/hidapitester.zip
unzip -o /tmp/hidapitester.zip -d ~/bin/
chmod +x ~/bin/hidapitester
```

### 3. Udev rule for Bolt
```bash
echo 'SUBSYSTEM=="usb", ATTRS{idVendor}=="046d", ATTRS{idProduct}=="c548", MODE="0666"' | sudo tee /etc/udev/rules.d/99-logitech-bolt.rules
sudo udevadm control --reload-rules && sudo udevadm trigger
```

### 4. Copy script
```bash
mkdir -p ~/scripts
cp to_mac.sh ~/scripts/
chmod +x ~/scripts/to_mac.sh
```

### 5. Keyboard shortcut (Ctrl+Shift+Up)
Settings → Keyboard → Custom Shortcuts:
- Name: KVM to Mac
- Command: /home/USER/scripts/to_mac.sh
- Shortcut: Ctrl+Shift+Up

---

## Mac Setup

### 1. Install m1ddc
```bash
brew install m1ddc
```

### 2. Copy script
```bash
mkdir -p ~/scripts
cp to_nobara.sh ~/scripts/
chmod +x ~/scripts/to_nobara.sh
```

### 3. Usage
```bash
~/scripts/to_nobara.sh
# Then press Easy-Switch on keyboard/mouse to Channel 2
```

---

## DDC Input Codes (Dell U3821DW)

| Input | Code |
|-------|------|
| HDMI 2 | 18 |
| USB-C | 27 |