Darrick Addison, an experienced developer in databases, networks, user interfaces, and embedded systems, introduces the field of robotics and the issues surrounding robotic systems. He covers mechanical design, sensory systems, electronic control, and software. He also discusses microcontroller systems, including serial and memory-mapped interfacing, and talks about some of the available open source software options.
http://thisara4g.blogspot.com/2008/03/introduction-to-robotics.html