You will first need to download the DeviceAtlas PHP API, available via their downloads page. Unpack this into your library, and make note of the directory in which it resides.
From there, you may optionally desire to download one of the DeviceAtlas databases; see their site for details. When you do, make sure you make note of where the data file resides.
Once you have this information, you may configure
Zend_Http_UserAgent to utilize it. The easiest way is through
your application configuration.
resources.useragent.deviceatlas.deviceatlas_lib_dir = APPLICATION_PATH "/../library/DeviceAtlas" resources.useragent.deviceatlas.deviceatlas_data = APPLICATION_PATH "/../data/DeviceAtlas/json/DeviceAtlas.json