Android + IOIO + Countdown Timer
Countdown timer Android app with IOIO output. When the timer goes off, it pulls the pin high, or low. The article demonstrates a proof of concept usage with a single LED, but this could easily be adapted for other usages: light switches and appliance control, detonators, etc.
For additional background information on interfacing Android with IOIO, check out my other introductory tutorials:
Background on Android development, IOIO, and electronics:
- Android Device (1.6+, 2.1 for Bluetooth)
- IOIO (available at Sparkfun)
- 330 ohm resistor
- Power supply
- Hook-up wire
For instructions and diagram, check out: Android + IOIO + Simple Digital Output
Get the source
git clone git://github.com/mitchtech/android_ioio_countdown_timer.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://github.com/ytai/ioio.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.
Controlling other devices
Here’s an updated video using the same source code and essentially the same circuit (transistor controlled relay) to control a 12V fire alarm bell.