Many of the embedded controllers and other chips used by robot builders include support for the Controller Area Network (CAN) bus. But what is it? And can it be used for anything interesting? Embedded.com provides a short introduction and overview on the subject, titled A short trip on the CAN bus. You'll learn that CAN is the most widely used bus architecture in automotive design. Interestingly CAN defines only the physical and data-link layer protocols, leaving the higher-level protocols to the user. This can lead to incompatibility but, fortunately, there are a couple of standard protocols that can be adopted. Embedded.com offers a second article comparing the two most common CAN bus protocols, CANopen and MicroCANopen.