Is there anything that today's CAN bus can't do?

By Tim Bresien, Microchip

From humble beginnings in the early 1990s, the CAN bus (Controller Area Network) has expanded from its base in automotive and industrial applications to connect and interconnect control systems in numerous other industries.

In traditional cars, the wiring system is quite daunting, with wires, data cables and criss-crossing control harnesses, making the vehicle difficult to repair. However, despite so many harnesses, the electronic functions of old cars are very few.

At the time, the first car to feature in-car connectivity via the CAN network was about to roll off the production line. This unique event would simplify automotive wiring and pave the way for incredibly advanced vehicle communications. It would kick off a series of networking milestones that would quickly culminate among automakers. Long before the commercial Internet, smartphones, or digital media, the introduction of the CAN bus redefined the possibilities of in-car communication and connectivity and sparked a growing technology landscape whose impact has transcended the automobile. The 1991 Mercedes S-Class model W140 was a trendsetter, featuring five CAN-connected electronic control units (ECUs).

Today's cars include as many as 60 to 100 ECUs and a wide variety of CAN networks and subnetworks connecting a dizzying array of electronic systems. On-board diagnostics (OBD) systems also utilize the information streams supported by CAN to provide real-time system performance data to drivers, mechanics, and regulators who monitor vehicle emissions.

The CAN protocol was originally developed by Robert Bosch for automotive applications in the mid-1980s and has become a trusted high-speed standard for applications that require reliable communication and high bandwidth utilization. The classic CAN protocol (ISO 11898) has also evolved into a development called CAN FD (ISO 11898-1) with faster rates to support the growing amount of data in smart cars. Advances in automotive design require sensor-driven capabilities to improve driver safety and optimize engine performance with little human intervention. Engine control units, automatic transmissions, active safety systems, seat control units, door modules, trailer interfaces, parking assist controls and collision avoidance systems continuously utilize CAN bus and CAN controller technology during vehicle operation. Data transmission speed and reliability are critical because systems can share network capacity in an instant while performing starts, stops and priority access.

Over the years, numerous standards bodies have redesigned the CAN-based standard for use in non-automotive industries, taking advantage of its short messaging capabilities and high transmission speeds through market-specific customizations of the upper layers of the protocol stack. You’ll find CAN-based networks in agricultural equipment, avionics, industrial and factory automation systems, smart buildings, medical systems, and many areas that would probably surprise the original inventors.

In fact, Microchip recently introduced a radiation-hardened microcontroller for space applications that includes a dual CAN controller in addition to Ethernet capabilities. CAN is also considered a reliable alternative for spacecraft control systems.

Microchip leverages our rich heritage in the automotive industry and our commitment to supporting our customers throughout their design process. Incorporating the CAN protocol into designs is a cost-effective communication option that provides a high degree of real-time capabilities for all electrical environments, from simple to complex. Microchip offers a complete range of products to meet the needs of high-performance embedded applications using the CAN protocol, including 8-bit, 16-bit and 32-bit microcontrollers, 32-bit microprocessors and digital signal controllers (DSCs) as well as integrated CAN, external CAN controllers and CAN transceivers. With easy-to-use development systems, code examples, drivers and application notes, Microchip offers a comprehensive CAN bus solution that enables low-risk product development, lower total system cost and faster time to market for high-performance embedded devices.