Hardware Guide

Complete guide to building and choosing hardware for OpenTrack trackers

This guide covers the hardware requirements, building instructions, and recommendations for all OpenTrack tracker types. Whether you’re buying ready-made hardware or building your own DIY tracker, this guide will help you get started.

Quick Hardware Comparison

Tracker	Cost	DIY Difficulty	Special Hardware	Best For
NeuralNet	$0-20	None	Webcam only	Easiest start, no markers
ArUco	$0-5	Easy	Webcam + printed marker	Quick setup, minimal cost
PointTracker	$30-80	Medium	IR LEDs + modified camera	Best performance
Easy Tracker	$30-80	Medium	IR LEDs + modified camera	Flexible point models
Wiimote	$15-50	Easy	Wiimote + IR LEDs	Budget-friendly IR tracking
HATire	$5-30	Medium-Hard	Arduino + IMU	DIY project, rotation only
Hydra	$50-150	Easy	Razer Hydra (discontinued)	6DOF, no line-of-sight
FreePIE UDP	Varies	Varies	Depends on source	Wireless, flexible

Camera-Based Tracker Hardware

Webcams for NeuralNet and ArUco

Recommended Webcams

Budget ($20-40):

• Logitech C270/C310
• Microsoft LifeCam HD-3000
• Any 720p webcam with good low-light performance

Mid-range ($40-80):

• Logitech C920/C922
• Logitech C930e
• Razer Kiyo

What to look for:

• 720p minimum, 1080p better for accuracy
• 30 FPS minimum, 60 FPS preferred
• Good low-light performance
• Manual exposure control
• Standard field of view (50-65°)

Mounting Position

Ideal camera placement:

• Top center of monitor
• At eye level or slightly above
• 50-80cm from face
• Angled slightly downward (5-15°)
• Stable mounting (no wobbling)

Mounting options:

• Clip-on monitor mount (usually included)
• Tripod with ball head
• Custom 3D printed bracket
• Adhesive mount on monitor bezel

IR Cameras for PointTracker and Easy Tracker

1. Option 1: PS3 Eye Camera (Recommended)

   Advantages:

   • No modification needed for IR
   • High framerate (up to 120 FPS at 320x240)
   • Low latency
   • Cheap ($5-15 used)
   • Wide availability

   Setup:

   1. Purchase PS3 Eye camera
   2. Install CL-Eye driver (Windows) or Linux driver
   3. Connect via USB
   4. Works immediately with IR LEDs

   PS3 Eye has built-in IR sensitivity. It’s the most popular choice for PointTracker.

2. Option 2: Modified Webcam

   Process:

   1. Choose a webcam with good sensor (see above recommendations)
   2. Disassemble camera carefully
   3. Locate IR filter (usually pink/red square glass)
   4. Remove IR filter
   5. Optionally: Add visible light filter (exposed film negative)
   6. Reassemble camera

   Result:

   • Camera now sees IR light
   • Normal colors will look wrong (not important for tracking)
   • Better IR sensitivity without visible light filter

   This permanently modifies your webcam for IR use only. Use a dedicated camera for tracking.

3. Option 3: Wiimote as IR Camera

   See Wiimote Tracker guide.

   No camera modification needed - Wiimote has built-in IR camera.

IR LED Hardware

Building an IR LED Array

1. Choose Your LEDs

   Wavelength:

   • 850nm (more common, visible red glow)
   • 940nm (truly invisible, harder to see)

   Power:

   • 20-100mW per LED
   • Higher power = better range
   • Lower power = longer battery life

   Viewing angle:

   • 30-60° recommended
   • Narrower = brighter but limited angle
   • Wider = more tolerance for head rotation

   Quantity:

   • Buy 10-20 LEDs ($5-10)
   • Use 3-5 for tracker
   • Extras for experimentation/failures
2. Gather Other Components

   Required:

   • Current limiting resistors (calculate based on LED specs)
   • Battery holder or USB power adapter
   • Wire (22-26 AWG)
   • Solder and soldering iron
   • Heat shrink tubing

   Power options:

   • 2xAA battery holder (3V)
   • 3xAA battery holder (4.5V)
   • USB power bank (5V with voltage regulator)
   • 9V battery (with appropriate resistors)

   Mounting:

   • Cap or headband
   • Hot glue or epoxy
   • Small project box for electronics
   • Velcro for removable mounting
3. Calculate Resistor Values

   Use Ohm’s law to find resistor value:

   R = (V_supply - V_led) / I_led
   

   Example:

   • Supply voltage: 5V (USB)
   • LED forward voltage: 1.5V (from datasheet)
   • LED current: 20mA = 0.02A
   • Resistor: (5 - 1.5) / 0.02 = 175Ω
   • Use standard 180Ω or 200Ω resistor

   For multiple LEDs in parallel, each needs its own resistor for even brightness.

4. Wire LEDs in Parallel

   Circuit:

   Battery+ ----[R1]----[LED1]---- Battery-
            |
            +---[R2]----[LED2]---+
            |
            +---[R3]----[LED3]---+
   

   Each LED gets its own current-limiting resistor.

5. Choose Point Configuration

   3-point triangle (most common):

         LED1 (top)
          /\
         /  \
        /    \
   LED2      LED3
   (left)    (right)
   

   • Asymmetric triangle (not equilateral)
   • Typical spacing: 60-100mm between points
   • Mount on cap brim or headband

   4-point configuration:

   • Add center LED or extend triangle
   • Better tracking stability
   • More complex to build

   5-point configuration:

   • Maximum stability
   • Best rotation range
   • Most complex
6. Mount and Secure

   1. Arrange LEDs in chosen pattern on cap/headband
   2. Hot glue or epoxy LEDs in place
   3. Secure wiring with tape or cable management
   4. Put electronics in small project box
   5. Use velcro to attach battery pack
   6. Add on/off switch for convenience

   Ensure LEDs don’t move relative to each other. Any flex affects tracking accuracy.

Pre-Built IR LED Solutions

TrackIR Clip

Official clip from NaturalPoint (~$40)

• 3 IR LEDs, pre-wired
• Clips on hat/headset
• Powered by USB
• Ready to use

DIY Community Builds

Search online for:

• TrackIR alternatives
• DIY head tracker LED caps
• 3D printed LED mounts
• Community shared designs

ArUco Marker Hardware

Printing Markers

1. Generate Marker

   Online generators:

   • Search “ArUco marker generator”
   • Select dictionary (e.g., 4x4_50)
   • Choose marker ID
   • Set size (50-100mm recommended)
   • Download as PNG or PDF

   Using OpenCV:

   import cv2
   aruco_dict = cv2.aruco.Dictionary_get(cv2.aruco.DICT_4X4_50)
   marker = cv2.aruco.drawMarker(aruco_dict, 0, 200)
   cv2.imwrite('marker.png', marker)
   
2. Print at Actual Size

   1. Print on quality printer (laser preferred)
   2. Ensure “actual size” or “100% scale” selected
   3. Use white paper, black ink
   4. High quality print settings
   5. Measure printed marker to verify size
3. Mount on Rigid Backing

   1. Glue marker to cardboard or foam board
   2. Ensure marker stays completely flat
   3. Optionally laminate for durability
   4. Attach to cap, headband, or clip

   Warped or bent markers significantly reduce tracking accuracy!

IMU Hardware for HATire

Recommended IMU Sensors

MPU6050 (Best Budget)

Specifications:

• 6-axis (gyro + accel)
• I2C interface
• Built-in DMP
• 3.3V or 5V compatible

Cost: $2-5

Pros:

• Very cheap
• Easy to use
• Good documentation
• DMP for sensor fusion

Cons:

• Gyro drift over time
• No magnetometer

BNO055 (Best Ease)

Specifications:

• 9-axis (gyro + accel + mag)
• I2C interface
• Built-in sensor fusion
• Outputs quaternions

Cost: $20-30

Pros:

• Hardware sensor fusion
• Very stable output
• Easy to program
• Excellent accuracy

Cons:

• More expensive
• Magnetometer calibration needed

MPU9250 (Best Value)

Specifications:

• 9-axis (gyro + accel + mag)
• I2C or SPI
• Lower drift than MPU6050

Cost: $5-10

Pros:

• Good price/performance
• Magnetometer included
• Widely available

Cons:

• No built-in fusion
• More complex to program

Arduino Selection

Board	Cost	Pros	Cons
Arduino Nano	$3-10	Compact, breadboard-friendly	Older micro-USB
Arduino Pro Micro	$5-10	Very small, native USB	Requires FTDI for some
Arduino Uno	$20-25	Easy for beginners, standard	Large for head mounting
ESP32	$5-15	WiFi + Bluetooth, powerful	Overkill for simple IMU

Arduino Nano or Pro Micro recommended for head mounting - small and lightweight.

Wiimote Hardware

Acquiring a Wiimote

Where to Buy

Used market:

• eBay: $15-30
• Local classifieds
• Retro game stores
• Pawn shops

What to look for:

• Original Nintendo Wii Remote
• Working condition (test Bluetooth)
• Includes battery cover
• Any color works

Avoid:

• Third-party controllers (may not work)
• Damaged units
• “Wii U” versions without IR (rare)

Mounting Solutions

Top of monitor:

• Small tripod
• Velcro strips
• 3D printed bracket
• Adjustable camera mount

Requirements:

• Stable (no wobbling)
• Points toward head
• Easy to adjust angle
• Wiimote can stay in place

Bluetooth Adapters

Most PCs have built-in Bluetooth, but if not:

• USB Bluetooth 4.0 adapter: $5-10
• Ensure Bluetooth 2.1+ (for Wiimote compatibility)
• Any brand usually works

Power Solutions

For IR LEDs

AA Batteries

2xAA (3V):

• Simple, portable
• Easy to replace
• Good runtime (10-20 hours)
• Battery holder: $1-2

3xAA (4.5V):

• Brighter LEDs possible
• Longer runtime
• Slightly heavier

USB Power

USB power bank:

• 5V regulated
• Need appropriate resistors
• Very long runtime
• Can be bulky

Direct USB:

• Wired to PC
• Infinite runtime
• Tethered

Rechargeable

LiPo battery:

• 3.7V nominal
• Compact, lightweight
• Rechargeable
• Need protection circuit
• Cost: $5-15

Setup:

• Battery + charging module
• Voltage regulator if needed
• More complex but elegant

For Arduino/IMU

• USB power from PC: Simplest, always powered
• USB power bank: Portable, wireless
• LiPo battery: Compact, needs charging circuit
• 9V battery: Easy but poor runtime

Tools and Supplies

Essential Tools

For IR LED Build

• Soldering iron and solder
• Wire strippers
• Multimeter (for testing)
• Hot glue gun
• Scissors/wire cutters
• Heat shrink tubing

For Arduino Build

• Soldering iron and solder
• Breadboard (for prototyping)
• Jumper wires
• USB cable
• Multimeter
• Small project box

Helpful Supplies

• Velcro strips: Removable mounting
• Cable management: Zip ties, cable clips
• 3D printer access: Custom mounts (optional)
• Heat shrink tubing: Protect solder joints
• Electrical tape: Quick fixes
• Small screws/bolts: Secure mounting

Safety Notes

Electrical Safety:

• Don’t exceed LED maximum current
• Use appropriate resistors
• Check polarity (LEDs are directional)
• Avoid short circuits
• Insulate all connections

IR Safety:

• High-power IR LEDs can harm eyes
• Use <100mW LEDs for safety
• Don’t stare directly at IR LEDs
• Diffuse beam if using high power

Cost Breakdown Examples

Budget Setup ($10-20)

Tracker Type: ArUco
Camera: Existing webcam ($0)
Marker: Printed paper ($0-1)
Mounting: Cardboard + tape ($0)
Total: ~$1

DIY IR Tracker ($30-50)

Tracker Type: PointTracker
PS3 Eye Camera: $10 (used)
IR LEDs (10x): $5
Resistors: $1
Battery holder + batteries: $3
Wire and supplies: $5
Cap or headband: $5
Total: ~$30

Wiimote Setup ($20-40)

Tracker Type: Wiimote
Wiimote: $20 (used)
IR LEDs (see above): $10
Bluetooth adapter: $0-10 (if needed)
Total: ~$30-40

Arduino IMU Tracker ($15-35)

Tracker Type: HATire
Arduino Nano: $5
MPU6050 IMU: $3
USB cable: $2 (or included)
Wires and headers: $2
Project box: $3
Total: ~$15 (or $35 with BNO055)

Where to Buy

Online Retailers

• AliExpress: Cheapest, long shipping (China)
• Amazon: Fast shipping, higher prices
• eBay: Used and new options
• Adafruit: Quality components, tutorials
• SparkFun: Reliable, good documentation
• Banggood: Good prices, moderate shipping

Local Options

• Electronics stores: Immediate availability
• Hobby shops: RC supplies
• Computer stores: Webcams, Bluetooth
• Thrift stores: Used webcams, Wiimotes

Next Steps

Once you have your hardware:

Configure Tracker

Set up your chosen tracker in OpenTrack

Calibrate

Calibrate for optimal tracking performance

Community Resources

• OpenTrack Forums: Build guides and troubleshooting
• Reddit r/HotasDIY: DIY tracking community
• Discord servers: Real-time help
• Thingiverse: 3D printable mounts
• GitHub: Arduino sketches and examples

See Also

• Tracker Overview - Compare all tracker types
• PointTracker Guide - Detailed IR LED tracker setup
• HATire Guide - Arduino IMU tracker setup