I have created a small utility which can evaluate "C" expressions and print it in Hex/Binary formats. The name of the project is Eva.
The core part - Parser is created using ANTLR. Actually the parser part contains 3 modules - Lexer, Parser and Tree walker. The GUI part is developed using WxWidgets.
Since it is a small project, I decided to post it in google code hosting rather than sourceforge. Here is the link to the project - http://code.google.com/p/eva-c/