How to Integrate a USB Iris Module into Your Product: OEM Guide

Why OEMs Are Adding Iris Recognition

The demand for embedded iris recognition is growing across multiple product categories: access control panels, handheld identity terminals, kiosk systems, ATMs, point-of-sale devices, and industrial tablets. OEMs integrating iris recognition into their products gain a significant competitive advantage by offering the highest-accuracy biometric modality available.

USB iris modules provide the fastest path to integration because they encapsulate the complete optical system (NIR LEDs, camera sensor, lens assembly) and processing logic (iris capture, quality assessment, segmentation) in a self-contained unit. The host product simply communicates with the module via USB, receives processed iris images or templates, and implements the application logic.

Step 1: Module Selection — MI30 vs MD31 vs MD20

HOMSH offers three primary USB iris modules targeting different OEM integration scenarios. Selecting the right module depends on your product's form factor constraints, capture distance requirements, single vs dual-eye needs, and power budget.

Selection guidelines: Choose the MI30 for space-constrained, battery-powered designs. Choose the MD31 for wall-mounted access control where dual-eye accuracy matters and size is less constrained. Choose the MD20 when you need I2C interface support for embedded systems without USB host capability.

For the complete product lineup and detailed datasheets, visit the HOMSH products page.

Step 2: Interface Selection — USB vs I2C

USB 2.0 Interface

USB 2.0 is the standard interface for most OEM integrations. It provides:

• 480 Mbps bandwidth — More than sufficient for streaming iris images at 10–15 fps.
• 5V bus power — The module draws power directly from the USB port, eliminating the need for a separate power supply.
• Plug-and-play enumeration — The module appears as a standard USB device (UVC class for image streaming or custom HID class for command/response protocol).
• Cable length — Supports up to 5m cable runs without a hub, suitable for most panel-mount installations.

I2C Interface (MD20 Only)

The MD20 module supports I2C for direct integration with microcontroller-based embedded systems:

• Low-level control — Direct register-level access to camera parameters, LED intensity, and capture timing.
• No USB stack required — Ideal for resource-constrained embedded processors that lack USB host capability.
• 400 kHz fast mode — Sufficient for transferring processed iris templates (256 bytes). Raw image transfer over I2C is slow; use I2C for template-level integration where the module performs on-board processing.
• Separate power input — I2C does not provide bus power; a dedicated 5V supply is required.

Step 3: SDK Platform Setup

HOMSH provides SDKs for three major platforms. Each SDK includes libraries, header files, API documentation, and sample applications with source code.

Windows SDK

• Supports Windows 10/11 (x64)
• C/C++ and C# APIs with Visual Studio project templates
• USB driver included (WinUSB-based, no custom driver installation required)
• Sample applications: enrollment, 1:1 verification, 1:N identification

Linux SDK

• Supports Ubuntu 20.04+, Debian 11+, and other glibc 2.31+ distributions
• C/C++ API with CMake build scripts
• Works with standard libusb (no kernel driver modifications required)
• ARM (v7a, v8a/aarch64) and x86_64 libraries provided
• Ideal for embedded Linux products (Raspberry Pi, Jetson, custom ARM boards)

Android SDK

• Supports Android 8.0 (API 26) and above
• Java and NDK (C++) APIs
• USB OTG communication via Android USB Host API
• AAR package for easy Gradle integration
• Sample application with camera preview, enrollment flow, and matching

Step 4: Integration Workflow

The typical OEM integration follows these sequential steps:

1. SDK evaluation (Week 1–2) — Download the SDK, connect the evaluation module to a development PC, and run the sample applications. Verify image quality, capture speed, and matching accuracy meet your product requirements.
2. Mechanical design (Week 2–6) — Design the module mounting in your product enclosure. Key considerations:
   • Optical window material: use NIR-transmissive glass or polycarbonate (transmittance >90% at 850nm)
   • Mounting orientation: module optical axis should align with the user's eye height
   • Ventilation: ensure adequate airflow to keep the module below 50°C operating temperature
   • EMI shielding: the USB cable should be shielded; keep it away from high-current power lines
3. Software integration (Week 4–10) — Implement the iris capture workflow in your application:
   • Initialize the module and configure capture parameters
   • Display the live camera preview with eye-positioning guide overlay
   • Call the capture API when the eye is detected within the capture zone
   • Receive the processed iris image and/or IrisCode template
   • Store templates in your application database
   • Implement 1:1 or 1:N matching using the SDK matching API
4. Quality testing (Week 8–12) — Test with a diverse population sample (different eye colors, ages, eyewear). Measure FTE, FRR, and FAR against your product specifications. Verify compliance with applicable image quality standards.
5. Certification (Week 10–14) — Submit for relevant certifications: CE/FCC for the complete product, and applicable biometric standards certification if required by your target market.

Power Requirements and Battery Considerations

For battery-powered products (handheld terminals, mobile enrollment devices), power management is critical. Here are the key specifications and design recommendations:

• Supply voltage — All modules operate on 5V DC +/-5%. Ensure your USB port or dedicated supply can provide stable 5V under the module's peak current draw.
• Peak current — During NIR LED illumination and image capture, the MI30 draws up to 300mA, the MD31 up to 440mA, and the MD20 up to 500mA at 5V.
• Standby current — When idle (no capture), modules draw 60–100mA. Use the SDK's sleep command to reduce standby draw to under 10mA.
• Duty cycle optimization — A typical attendance check requires 1–2 seconds of active capture. For a device processing 200 checks per day, total active time is under 7 minutes. Design your power budget around actual duty cycle, not continuous operation.
• Inrush current — On power-up, the module's LED driver may draw a brief inrush current spike of 1.5x nominal. Size your power supply accordingly and add a 100uF capacitor close to the module's power input.

Image Quality Standards: GB/T 33767.6-2018

For products deployed in China, compliance with GB/T 33767.6-2018 (Information Technology — Biometric Sample Quality — Part 6: Iris Image Data) is typically required for government and enterprise contracts. Key requirements include:

HOMSH modules include built-in image quality assessment that evaluates each captured frame against these parameters in real time. The SDK's quality score API returns a per-frame quality vector, allowing your application to accept only images that meet the standard. This eliminates the need for OEMs to implement their own quality assessment logic.

For international markets, ISO/IEC 29794-6 defines equivalent quality metrics. HOMSH modules comply with both standards simultaneously.

Common Integration Pitfalls and Solutions

• Optical window reflections — If the product's optical window is not anti-reflection coated, NIR LED light may reflect back into the camera sensor, causing image washout. Solution: use AR-coated glass with <1% reflectance at 850nm, or angle the window 5–10 degrees from perpendicular.
• Ambient NIR interference — Outdoor sunlight contains strong NIR components that can overwhelm the module's illumination. Solution: use a narrow-band 850nm optical filter on the camera lens (included in HOMSH modules) and design a lens hood or recessed mounting to shade the optical window.
• USB enumeration delays — On some Android devices, USB OTG enumeration can take 2–5 seconds after cable connection. Solution: keep the module powered continuously and use the SDK's warm-start mode to skip re-initialization.
• EMI from nearby components — High-speed switching regulators, displays, and wireless modules can introduce noise into the USB signal. Solution: use shielded USB cables, add ferrite beads on USB data lines, and maintain physical separation between the iris module and EMI sources.
• Thermal issues — In enclosed products without ventilation, module temperature may exceed the 50°C operating limit. Solution: add thermal vias to the PCB mounting area or a small passive heatsink to the module's metal housing.

OEM Support and Engineering Assistance

HOMSH provides comprehensive OEM support throughout the integration process:

• Evaluation kits — Complete development kits with module, USB cable, SDK, and sample applications available for all three module families.
• Mechanical drawings — 3D STEP files and 2D DXF drawings for all modules, available under NDA.
• Integration support — Dedicated FAE (Field Application Engineer) assigned to each OEM project for technical guidance during development.
• Custom firmware — For high-volume OEM projects (1,000+ units/year), custom firmware configurations including modified LED intensity, capture distance tuning, and custom USB VID/PID are available.
• MOQ and pricing — Sample quantities available for evaluation; production pricing at MOQ of 100 units with volume discounts at 500 and 1,000+.

Frequently Asked Questions