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huion_inspiroy_h640p.md

Inspiroy H640P Tablet Guide for Fedora

A comprehensive reference for using your Inspiroy H640P drawing tablet with OpenTabletDriver on Fedora Linux.

Quick Start

First Connection

  1. Connect the tablet via USB cable
  2. Check OpenTabletDriver status: 
    systemctl --user status opentabletdriver
  3. Start the daemon if not running: 
    systemctl --user start opentabletdriver
  4. Launch the GUI: 
    otd-gui

Initial Testing

Yes, your tablet works as a mouse by default! Here's how to test:

  1. Basic Movement Test

    • Move your pen over the tablet surface (without touching)
    • Your cursor should move on screen
    • The entire tablet surface maps to your entire screen

  2. Pressure Test

    • Open OpenTabletDriver GUI → Go to "Tester" tab
    • Touch the pen to the tablet
    • You should see pressure values change (0-8191 on this model)
    • Tilt the pen to see tilt values

  3. Button Test

    • Press each button on the tablet
    • Watch for responses in the OTD GUI
    • The pen buttons should also register

Understanding Your H640P

Specifications

  • Active Area: 6.3 x 3.9 inches (160 x 100 mm)
  • Pressure Levels: 8192
  • Resolution: 5080 LPI
  • Report Rate: 266 PPS
  • Pen: Battery-free, with 2 buttons
  • Tablet Buttons: 6 express keys on the side

How It Differs from a Mouse

  • Absolute positioning: Each point on tablet = specific screen point (not relative like a mouse)
  • Pressure sensitivity: Press harder = thicker/more opaque strokes in painting apps
  • Pen hover: Cursor moves without touching (hover distance ~10mm)
  • Tilt sensitivity: Pen angle can affect brush behavior

Configuring OpenTabletDriver

Opening Settings

otd-gui

Expected UI Layout:

  • Tabs at top: Output | Filters | Pen Settings | Auxiliary Settings | Tools | Console
  • Display section: Shows your monitor(s) and their resolution
  • Tablet section: Shows your H640P's active area (160mm x 100mm)
  • Bottom left: Mode dropdown (should show "Artist Mode")
  • Bottom right: Save and Apply buttons

Your screenshot shows the correct layout.

Essential Settings to Configure

1. Tablet Area (Important!)

By default, the entire tablet maps to all your screens. For better control:

  • Go to "Tablet" tab
  • Click "Area Editor"
  • Options:
    • Full area: Use entire tablet (less precise but more arm movement)
    • Partial area: Use center portion (more precise, less movement)
    • Lock aspect ratio: Match your screen ratio to avoid distortion

Recommendation: Start with full area, adjust later if needed.

2. Output Mode (Bottom Dropdown)

In the OTD GUI, you'll see a dropdown at the bottom left that shows your current mode:

  • Artist Mode (Absolute): Tablet position directly maps to screen position
    • This is what you want for drawing - it's the default
    • Touch top-left of tablet = cursor goes to top-left of screen
    • Precise and predictable for artwork
  • Relative Mode: Works like a mouse
    • Moving pen moves cursor relative to current position
    • Rarely useful for art, more for mouse replacement

You're already on Artist Mode (Absolute) - keep it that way!

3. Pen Pressure Curve

  • Go to "Pen Settings" tab
  • Adjust the curve to match your pressure:
    • Linear: Natural pressure response
    • Soft curve: Less pressure needed for full opacity
    • Hard curve: More pressure needed

Test in GIMP to find your preference!

Button Configuration

Tablet Express Keys (6 Side Buttons)

Configure in OpenTabletDriver GUI → "Bindings" tab:

Recommended Setup for GIMP:

Button Suggested Action Why
1 Keyboard: Ctrl+Z Undo
2 Keyboard: Ctrl+Shift+Z Redo
3 Keyboard: [ Decrease brush size
4 Keyboard: ] Increase brush size
5 Keyboard: Ctrl+S Quick save
6 Keyboard: Space Pan tool (hold)

How to Set:

  1. Click on a button slot
  2. Choose binding type:
    • Keyboard: Single key or combination
    • Mouse Button: Left/right/middle click
    • Plugin Action: Advanced features
  3. Save settings

Pen Buttons (2 Buttons on Stylus)

Default Setup:

  • Lower button: Right-click (context menu)
  • Upper button: Middle-click or custom

Recommended:

  • Lower: Keep as right-click
  • Upper: Set to Ctrl (hold for eyedropper in GIMP)

Ergonomic Tip: Many artists disable pen buttons to avoid accidental clicks. Try it both ways!

Using with GIMP

Initial GIMP Setup

1. Configure Input Devices

Edit → Preferences → Input Devices → Configure Extended Input Devices
  • Find your tablet in the list
  • Set Mode to "Screen"
  • Click Save and restart GIMP

2. Enable Pressure Sensitivity

For each brush tool you use:

  1. Select the tool (Paintbrush, Pencil, Eraser, etc.)
  2. Open Tool Options panel (usually on left)
  3. Click the "Dynamics" dropdown
  4. Select "Pressure Opacity" or "Pressure Size" (or create custom)
  5. Test: light touch = transparent/thin, hard press = opaque/thick

Paint Dynamics Options:

  • Pressure Opacity: Pressure affects transparency
  • Pressure Size: Pressure affects brush size
  • Pressure Hardness: Pressure affects edge hardness
  • Pressure Color: Custom dynamics editor

3. Create Custom Dynamics

Windows → Dockable Dialogs → Paint Dynamics
  1. Click "New Dynamics" icon
  2. Name it (e.g., "My Pressure Setup")
  3. Check boxes for:
    • Opacity: Pressure
    • Size: Pressure (or Velocity for natural strokes)
    • Hardness: Pressure (optional)
  4. Select this dynamics preset for your tools

Essential GIMP Shortcuts for Tablet Use

Action Shortcut Tip
Brush tool P Main painting tool
Eraser Shift+E -
Eyedropper O or hold Ctrl Sample colors
Zoom in/out + / - Or Ctrl+scroll
Rotate canvas Shift+Ctrl + middle-drag Rotate for comfortable strokes
Increase brush ] Map to tablet button!
Decrease brush [ Map to tablet button!
Undo Ctrl+Z Map to tablet button!
Toggle fullscreen F11 More canvas space

Workflow Tips for GIMP + Tablet

Best Practices

  1. Use Layers: Always paint on separate layers

  2. Enable "Smooth Stroke": In Tool Options → Quality → Smooth stroke

    • Helps stabilize shaky lines

  3. Use Symmetry Painting:

    Windows → Dockable Dialogs → Symmetry Painting
    • Great for mandalas, characters, etc.

  4. Canvas Rotation:

    • Shift+Ctrl + middle mouse drag (or stylus button)
    • Rotate canvas for natural stroke angles
    • Doesn't rotate actual image, just view

Tablet-Specific GIMP Settings

For smoother drawing:

Edit → Preferences → Input Devices → Input Controllers
  • Adjust "Grab broken" setting if cursor jumps
  • Increase "Sample averaging" for smoother curves

Disable Windows Ink (if you have issues):

  • Usually not needed on Linux, but if you experience cursor offset:
# Check if any Windows compatibility layers are interfering

Common Issues & Solutions

Tablet Not Detected

# Check if tablet is connected
lsusb | grep -i huion

# Restart the driver
systemctl --user restart opentabletdriver

# Check logs
journalctl --user -u opentabletdriver -f

Cursor Offset in GIMP

Solution: Map tablet to single display

In OTD GUI:

  • Go to "Display" tab
  • Select your primary monitor
  • Tablet will now only control that screen

Pressure Not Working in GIMP

  1. Check Tool Options → Dynamics is enabled
  2. Verify pressure works in OTD GUI Tester tab
  3. Restart GIMP after configuring tablet
  4. Check Edit → Preferences → Input Devices

Buttons Not Responding

  1. Open OTD GUI while pressing buttons
  2. Check if they register in "Bindings" tab
  3. Some buttons may need "Ignore Input" toggled off
  4. Restart OTD daemon after changes

Pen Feels Too Sensitive/Stiff

  1. Adjust pressure curve in OTD GUI
  2. In GIMP, customize Paint Dynamics:
    • Adjust pressure curve in dynamics editor
    • Add velocity for more natural feel

Advanced Tips

Multi-Monitor Setup

Issue: Tablet maps to all screens, making it hard to control

Solution:

  • OTD GUI → Display tab
  • Select single monitor for tablet output
  • Or adjust tablet area to match screen aspect ratio

Creating Tablet Profiles

Save different configurations for different programs:

  1. Configure settings in OTD GUI
  2. Settings are saved automatically
  3. For per-app settings, use: 
    otd-gui → Plugins → Application-Specific Settings

Pen Tilt in GIMP

H640P supports tilt. To use:

  1. GIMP → Paint Dynamics editor
  2. Check "X Tilt" and "Y Tilt" columns
  3. Bind to Size, Angle, or other attributes
  4. Great for calligraphy brushes!

Battery-Free Pen

Your pen uses electromagnetic resonance (EMR) technology:

  • ✅ Never needs charging
  • ✅ No batteries to replace
  • ✅ Lighter weight
  • Just hover to wake it up!

Quick Reference Commands

# Start OpenTabletDriver
systemctl --user start opentabletdriver

# Enable auto-start on boot
systemctl --user enable opentabletdriver

# Open GUI
otd-gui

# Check tablet connection
lsusb | grep -i huion

# View driver logs
journalctl --user -u opentabletdriver -f

# Restart driver
systemctl --user restart opentabletdriver

Learning Resources

Practice Exercises for New Tablet Users

  1. Circles: Draw circles in different sizes without lifting pen
  2. Straight lines: Practice horizontal and vertical lines
  3. Pressure control: Draw lines from light to heavy pressure
  4. Speed control: Fast and slow strokes with consistent width
  5. Figure-8s: Smooth continuous motion

GIMP Learning Path

  1. Start with basic brushes and pressure opacity
  2. Learn layers and layer masks
  3. Explore blend modes
  4. Try symmetry painting for fun results
  5. Experiment with custom brushes

Helpful Links

Maintenance

Keep Pen Nibs Fresh

  • Your pen comes with extra nibs
  • Replace when nib feels scratchy or worn down
  • Use nib removal tool (included) or tweezers

Keep Tablet Surface Clean

  • Use microfiber cloth
  • Slightly damp for sticky spots
  • Don't use harsh chemicals
  • Clean regularly to maintain smooth glide

Update OpenTabletDriver

# Check for updates via your package manager
sudo dnf update opentabletdriver

# Or build from source for latest features

Troubleshooting Checklist

  • Tablet connected via USB
  • OpenTabletDriver daemon running
  • Tablet detected in OTD GUI
  • Pressure registers in OTD Tester
  • GIMP input device set to "Screen" mode
  • Paint Dynamics enabled in GIMP tools
  • Buttons configured in OTD Bindings tab
  • Single monitor selected if using multi-display
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