The IOIO-OTG (pronounced “yo-yo-O-T-G”) features a PIC microcontroller which acts like a bridge that connects an app on your PC or Android device to low-level peripherals like GPIO, PWM, ADC, I2C, SPI, and UART. An app-level library helps you write control code for these low level peripherals in the same way you'd write any other Java app! 

IOIO Users Group:

https://groups.google.com/d/forum/ioio-users

IOIO Gallery:

http://pinterest.com/ytaibt/ioio/

And this is the blog of Ytai, the inventor of IOIO, where new developments are normally announced. Specifically, this introductory post provides a good overview of this technology.

User Documentation

Starters

• Read This Before Connecting - a really short must-read for the impatient to avoid damaging the board.
• IOIO Beginner's Guide - a "getting started" step-by-step tutorial for building your first IOIO application.
• Eclipse Troubleshooting - problems and solutions to common Eclipse-related problems.

Hardware

• Getting to Know the IOIO-OTG Board - information about the IOIO-OTG board and the I/O pins.
• Power Supply (IOIO-OTG) - how to power the IOIO-OTG board, power considerations.

Connectivity

Android:

• IOIO Over ADB
• IOIO Over Bluetooth for Android
• IOIO Over OpenAccessory

PC:

• Using IOIO With a PC
• IOIO Over Bluetooth for PC

Software

• IOIOLib Basics - overview of IOIOLib.
• IOIOLib Core API - introduction to the IOIO interface.
• IOIOLib Application Framework - an important set of utilities that simplify IOIO-based application authoring.
• Digital I/O - get those 0's and 1's in and out.
• Analog Input - measure voltage.
• PWM Output - generate pulse width modulation signals.
• Pulse Input - measure pulse width and frequency.
• UART - communicate with serial devices.
• SPI - control SPI devices as a host.
• TWI - control I²C and SMBus devices as a host.
• Capacitive Sensing - touch-sensing by measuring capacitance.
• Motor Control Sequencer - precise and synchronized control of various kinds of motors and actuators.

Resources

• Downloads - this page has links to download all the software and firmware you'll need for development.
  
• Release Notes - change log of the various versions of the software and firmware.
• Supported Devices - a list of all tested devices.
• Supported Bluetooth Dongles - a list of all tested bluetooth dongles

Tools

• IOIO-OTG Bootloader and IOIODude - a guide on using the IOIODude application that lets you upgrade the firmware on your IOIO-OTG board.
• The IOIO Manager Application - a guide on using the Android application that lets you upgrade the firmware on your IOIO v1 board.
• IOIO Bridge - use IOIO with the Android emulator or with a target Android being debugged.

 

Package includes:

• IOIO OTG development board 
• OTG cable