External I/O board for Android devices
Developer Ytai Ben-Tsvi has announced a new model of the IOIO board, which can be used to add measurement and control inputs and outputs to Android smartphones and tablets. Unlike Google's Accessory Development Kit (ADK), the IOIO is not restricted to Android versions 2.3.4 and higher – it also runs with older versions.
USB-on-the-go (OTG) is available, which means that the new model allows configuration of the operating mode it should use – it can register itself as a host on a smartphone or as a device on a PC. In the latter case, Tsvi sees the board as being an alternative to Arduino, allowing a higher bandwidth (with the exception of the Arduino Leonardo). The firmware for the IOIO even supports Bluetooth dongles, rendering a USB cable unnecessary.
The IOIOLib Java library makes programming for the device simple. When creating an Android app, the programmer directly addresses the ports or pins and controls what they should do. For example, the command
PwmOutput pwm = ioio.openPwmOutput(5, 50);
starts a 50Hz PWM signal to pin 5 of the IOIO board. The
pw variable controls the pulse width within a cycle and can, for example, be used to control the position of a servo.
The release date for the new model has not yet been decided, but, according to the developer, the new firmware is as good as finished. At $50 (approximately £32), the new board is expected to be cheaper than the previous model.