This is the Android app for Columbus. It lives on users' Android phones and collects data every three minutes. Data is uploaded only on Wi-Fi.

The app collects the following data:

• Image (front-facing camera)
• 10-second sound clip (microphone)
• Location (mobile triangulation)

The image and sound files are uploaded to an Amazon S3 bucket. When all of the above data has been collected, the app submits a JSON string to the backend server, similar to the following:

{
    "timestamp": 12345,
    "account_id": "[email protected]",
    "location": {
        "lat": 200,
        "lon": 1
    },
    "audio_url": "[email protected]/12345/audio.aac",
    "image_url": "[email protected]/12345/image.jpg"
}

audio_url and image_url - S3 key to the media assets

The app will only use the network if the phone is connected to Wi-Fi. If there is no Wi-Fi connection at the time of data collection, the upload job will be queued for later until Wi-Fi is available.

Libraries used:

• loopj HTTP library
• Google GSON library
• AWS Android SDK