MINI USB Host Shield 2.0 ADK - Support Google Android ADK

Product Overview

The MINI USB Host Shield 2.0 ADK is a compact USB host interface based on the MAX3421E controller. Designed primarily for 3.3 V microcontrollers (e.g., Arduino Pro Mini, FTDI), it enables USB host functionality including keyboard, mouse, U‑disk, camera support, and Android ADK compatibility. It even supports USB hub operation when used with the appropriate library 

Electrical & Interface Specifications

• Controller IC: MAX3421E USB Host Controller
• Operating Voltage: 3.3 V DC (you can use a logic level shifter module for 5V)
• Communication with MCU: SPI interface (MOSI, MISO, SCK, SS, IRQ)
• USB Port: Type‑A female connector
• USB Host Features:
  • Supports USB 2.0 Full-Speed devices (up to 12 Mb/s)
  • Compatible with keyboards, mice, flash drives, and cameras
  • Android Open Accessory (ADK) support (e.g., Nexus One, Nexus S, Droid X)
  • USB hub capability via USB Host Shield Library 2.0

Compatibility & Requirements

• Target Boards:
  • Arduino Pro Mini (3.3 V/8 MHz)
  • 3.3 V FTDI breakout boards
• Library Support: Fully compatible with USB Host Shield Library 2.0 (founded by Oleg Mazurov / felis)

Mechanical Details

• Dimensions: 38 × 18 mm
• Weight: ~4.5 g
• Form Factor: Designed to stack onto Pro Mini or be used as SPI breakout

Key Features

1. Compact USB Host Module - Ideal for adding USB support in space-limited projects
2. 3.3 V Logic - Safe for 3.3 V MCUs (Pro Mini, FTDI), preventing level-shifting
3. USB OTG/ADK Ready - Enables Arduino to act as Android accessory using ADK protocol
4. USB Hub Support - Can manage multiple USB devices via hub
5. SPI-Based Design -  Compatible with standard SPI pins and libraries
6. Open Source - Includes schematic, EAGLE files, Arduino library examples

Typical Use Cases

• Adding USB device support (e.g., flash drives, keyboards) to Arduinos for data logging
• Building Android accessory applications, such as game controllers or IoT endpoints
• Integrating camera or sensor devices via USB into Arduino systems
• Designing compact USB-host equipped projects with limited board space

Technical Summary

Integration Tips

• Ensure your Arduino runs at 3.3 V; a 5 V MCU requires level‑shifting or voltage-adjustment
• Include the USB Host Shield 2.0 library in your project for plug-and-play example code
• For Android ADK: use provided sample APK and firmware sources
• If using USB hubs, power hub adequately to avoid enumeration failures