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Android + IOIO + Simple Digital Input

Simplest possible digital input with Android and IOIO. This article will discuss the bare minimal requirements for development of an Android USB (or Bluetooth) digital input device.

The goal is to demonstrate the easiest possible use of the technology. For additional background information on Android development, IOIO, and electronics, check out these links:

IOIO for Android Beginners Guide
Android Developer’s Guide



Parts needed:

  • Android Device (1.6+, 2.1 for Bluetooth)
  • IOIO (available at Sparkfun)
  • 2x Push button
  • Breadboard
  • Power supply
  • Hook-up wire



Connect one side of each button to ground and the other side to the digital input pins. The example uses pins 34 and 35 but can be used with any IO pin (all IOIO pins are GPIO pins). Here is a diagram of the completed circuit (created with Fritzing):



Get the source

With the circuit assembled, the next step is to get the demo application on the Android device. You can either download the pre-built .apk or checkout the source from Github:

git clone git://

If you are building from source, you will also need to import the IOIO Library project, and optionally the IOIO Bluetooth library projects, both available here:

git clone git://


Install, connect, profit!

Finally, upload the app to the Android device (or browse to this page on the device and download the apk above). Connect the device to the IOIO, and start up the app.