The RF22 library has now been superceded by the RadioHead
library
http://www.airspayce.com/mikem/arduino/RadioHeadRadioHead and its RH_RF22 driver provides all the features supported by RF22, and much more
besides, including Reliable Datagrams, Addressing, Routing and Meshes. All the platforms that
RF22 supported are also supported by RadioHead.
This library will no longer be maintained or updated, but we will continue to publish
it for the benefit of the the community, and you may continue to use it within the terms of
the license. Nevertheless we recommend upgrading to RadioHead where
possible.