SAE J1939 development has evolved far beyond traditional automotive Electronic Control Units (ECUs). Today, engineers can build J1939-enabled systems using low-cost embedded platforms such as the ESP32 and the Raspberry Pi. While both platforms can successfully communicate on a J1939 network, they serve very different purposes. The question is not…
Posts published in “Misc. J1939”
As heavy-duty vehicles become increasingly connected, engineers are looking for ways to integrate vehicle data into fleet management systems, cloud applications, industrial control systems, and enterprise databases. The hardware needed for such integrations is readily available. Products from companies such as Red Lion, Moxa, HMS, Sierra Wireless, and many others…
For engineers working with agricultural machinery, one question comes up repeatedly: “Is ISOBUS just another name for J1939?” The short answer is: Almost—but not quite. Both protocols share the same technical roots, use the same physical CAN bus technology, and exchange messages using Parameter Group Numbers (PGNs). In fact, a…
One of the questions that recently crossed my mind was whether our existing SAE J1939 gateways and monitoring tools could be useful in the agricultural sector, specifically for monitoring ISOBUS networks. The short answer appears to be: Yes, in many cases they can. The longer answer is a bit more…
One of the most common misconceptions in the heavy-duty vehicle and industrial control markets is the assumption that a device using CAN 2.0B with a 29-bit identifier is automatically SAE J1939 compatible. Unfortunately, that assumption has caused countless integration headaches, wasted engineering hours, and unnecessary investments in development tools and…
If you have recently started working with SAE J1939, chances are your search history looks something like this: How do I monitor J1939 traffic? What hardware do I need for J1939 development? How do I simulate a J1939 ECU? How can I test my software without connecting to a real…
If you spend enough time around CAN Bus and SAE J1939 discussions, you’ll eventually encounter a statement along these lines: “Why implement a J1939 stack in firmware when Linux already supports J1939?” It’s a fair question. Modern Linux kernels include native J1939 support as part of the SocketCAN framework, and…
One of the more common questions when analyzing or simulating SAE J1939 traffic is surprisingly simple: “How accurate must a J1939 message frequency be?” If a message is supposed to be transmitted every 100 milliseconds, does that mean exactly 100 milliseconds? Can it be 101 milliseconds? 105 milliseconds? What happens…
If you spend enough time around CAN bus systems, you eventually encounter the magical little box known as the CAN repeater. Depending on who is explaining it, the device is either: the cure for all network problems, a way to build “unlimited” CAN networks, a signal booster, or a mysterious…
If you are new to SAE J1939, the first thing you will probably do is search for the official standards documents. That usually leads to an immediate moment of confusion. You discover that SAE J1939 is not a single document. It is an entire collection of standards. Hundreds of pages.…
