Copperhill Technologies

08/24/2026

Does a two-node CAN network behave exactly like a larger CAN network?

Not always.

Two CAN nodes can communicate perfectly well under normal conditions. But things become much more interesting when errors, Bus Off, ACK failures, or Listen-Only mode enter the picture.

In this new **JCOM1939 Engineering Note**, I take a closer look at the often-overlooked problems of two-node CAN test benches.

The article was inspired in part by an unusual “runaway” behavior I observed while testing JCOM1939 in Silent Mode with a PEAK PCAN analyzer. A periodically transmitted CAN frame suddenly appeared at a much higher frequency. The explanation leads directly into CAN acknowledgment, automatic retransmission, error confinement, and the special circumstances created when only two active nodes are present.

The article also examines:

• What happens when error detection becomes ambiguous
• What happens when one of only two nodes goes Bus Off
• Why CAN itself cannot detect a missing ECU
• Why Listen-Only mode can change the behavior of a two-node test bench
• Why adding another active CAN node can make testing more representative of a real-world network

Read the complete Engineering Note:

https://jcom1939.com/the-two-node-can-bus-problem-error-handling-bus-off-and-silent-mode/

Explore how two-node CAN networks behave during errors, Bus Off, ACK failures, and Listen-Only mode, and why adding a third active CAN node can improve testing.

08/24/2026

CAN FD provides significantly more data capacity and higher throughput than Classical CAN—but taking full advantage of it requires a processor capable of handling both communication and demanding real-time application tasks.

The Microchip dsPIC33CK256MP502 combines a 100 MHz Digital Signal Controller with an integrated CAN FD controller, making it an interesting platform for industrial control, sensor processing, motor control, automotive electronics, robotics, and other embedded applications.

In our latest article, we take a closer look at the dsPIC33CK256MP502, its CAN FD capabilities, and our CAN FD Demo Board as a practical development platform.

The board includes an onboard CAN FD transceiver, 8–24 VDC power input, UART connectivity, and I²C/Qwiic expansion. Demonstration firmware and an MPLAB X/MCC Melody project provide a starting point for developing your own CAN FD applications.

Read the full article:

https://copperhilltech.com/blog/developing-highperformance-can-fd-applications-with-the-microchip-dspic33ck256mp502/

08/14/2026

CAN FD and SAE J2716 SENT serve very different roles in automotive electronics—but together they provide a powerful combination for sensor development, ECU testing, and vehicle network applications.

**SENT (Single Edge Nibble Transmission)** is standardized under SAE J2716 and is designed primarily for point-to-point communication between automotive sensors and electronic control units. Instead of relying on an analog sensor voltage, SENT allows sensors to transmit high-resolution digital measurements directly to an ECU.

**CAN FD**, meanwhile, provides high-speed network communication between ECUs and other intelligent devices throughout the vehicle.

Together, the technologies can represent the complete path from the physical sensor to the vehicle network:

**Sensor → SENT → ECU → CAN FD → Vehicle Network**

Supporting both interfaces on the same development platform opens up some interesting possibilities:

• SENT sensor evaluation and data acquisition
• Sensor simulation for ECU development
• ECU and fault-response testing
• SENT-to-CAN FD gateway development
• Automotive test benches
• Hardware-in-the-loop applications
• Correlating sensor measurements with CAN/CAN FD network traffic

Our latest article takes a closer look at how SAE J2716 SENT works, how it differs from CAN FD, and why combining the two technologies on a Raspberry Pi can create a versatile automotive development and testing platform.

https://copperhilltech.com/blog/can-fd-and-sae-j2716-sent-automotive-sensor-communication-testing-and-applications/

08/12/2026

We’re continuing to develop the JCOM1939 Monitor into a more capable, professional environment for SAE J1939 development, simulation, diagnostics, and testing.

An upcoming software and firmware update adds improved CAN Bus diagnostics and a new Silent (Listen-Only) Mode. DM1 and DM2 diagnostic support is planned for the next version.

But we also want to hear from the engineers who actually use JCOM1939.

How do you use JCOM1939 today—monitoring, analysis, ECU simulation, testing, troubleshooting, or something else?

More importantly: **Which features would make JCOM1939 more useful in your work?**

We already have a development roadmap, including timestamps, message-frequency measurements, traffic replay, higher-speed data capture, and future SAE J1939-22/CAN FD support. Some of these will require our next-generation hardware, but we're particularly interested in improvements we can make to the current JCOM1939 platform.

Customer feedback has already influenced recent development, and we'd like that to continue.

Read the full post and tell us what you would like to see:
https://jcom1939.com/jcom1939-monitor-software-update-and-future-j1939-features/

In a recent article, JCOM1939 Monitor Update Adds CAN Bus Diagnostics and Silent Monitoring Mode, we introduced several improvements currently being prepared for the JCOM1939 Monitor software for Windows. The upcoming release adds improved CAN Bus diagnostics, including receive and transmit error co...

08/06/2026

Not every SAE J1939 development project requires a multi-thousand-dollar enterprise software suite.

Today's engineers have access to a wide range of development tools—from professional CAN interfaces and enterprise development platforms to affordable, dedicated J1939 applications. The key is understanding which solution best fits your workflow, technical requirements, and budget.

In our latest article, we take an objective look at the current J1939 development tool market, compare the different categories of products, discuss pricing, and explain why many engineers build a toolbox of complementary solutions rather than relying on a single application.

Whether you're developing embedded firmware, testing ECUs, diagnosing vehicle networks, or teaching J1939 concepts, this guide can help you make a more informed decision.

Read the full article here:
[https://jcom1939.com/choosing-the-right-sae-j1939-development-tool-a-practical-market-overview/](https://jcom1939.com/choosing-the-right-sae-j1939-development-tool-a-practical-market-overview/)

Have you found a combination of CAN hardware and software that works particularly well for your projects? We'd love to hear about your experience in the comments.

08/05/2026

How do you test fleet management software without driving a truck across the country?

Modern telematics systems combine GPS positioning with SAE J1939 vehicle data to provide fleet managers with valuable insights into vehicle performance, fuel consumption, maintenance needs, and driver behavior. While simulating J1939 data is relatively straightforward, creating realistic GPS movement remains one of the biggest challenges for developers.

In our latest article, we explain:
• What telematics is and why it has become essential for fleet management
• How GPS and J1939 work together
• Current methods for simulating GPS routes
• Why integrated GPS route simulation could dramatically simplify telematics software development

We're also considering GPS route simulation as a future enhancement to the JCOM1939 Monitor and would love to hear your thoughts. If this capability would benefit your development or testing workflow, please let us know.

Read the full article:
[https://jcom1939.com/understanding-telematics-and-gps-route-simulation-for-fleet-management-testing/](https://jcom1939.com/understanding-telematics-and-gps-route-simulation-for-fleet-management-testing/)

08/05/2026

Looking for an easy way to develop and test your SAE J1939 application without access to a running diesel engine?

Our SAE J1939 Simulator continuously generates the PGNs most commonly used by diesel engines, making it an ideal tool for software development, hardware validation, demonstrations, training, and production testing.

The simulator can transmit data such as:
• Engine speed
• Vehicle speed
• Oil pressure
• Coolant temperature
• Fuel level
• GPS position
• And many other standard J1939 parameters

Additional information, including VIN and engine hours, can also be simulated when required.

Whether you're developing ECUs, CAN Bus interfaces, data loggers, telematics devices, or diagnostic software, the J1939 Simulator provides a reliable and repeatable test environment.

Learn more:
[https://jcom1939.com/sae-j1939-simulator-generates-pgns-frequently-used-for-diesel-engine-simulation/](https://jcom1939.com/sae-j1939-simulator-generates-pgns-frequently-used-for-diesel-engine-simulation/)

08/03/2026

**Building a Classical CAN to CAN FD Gateway with the ESP32-S3**

Many existing CAN-based systems still perform their jobs perfectly—but replacing them just to support CAN FD isn't always practical. A Classical CAN to CAN FD gateway provides an efficient way to connect legacy devices to modern CAN FD networks without redesigning hardware or rewriting firmware.

In this article, we explain why Classical CAN and CAN FD cannot share the same physical network, when a gateway is the right solution, and how the ESP32-S3 Board with CAN FD and Classical CAN Ports makes implementation straightforward. We also cover advanced features such as message filtering, identifier translation, frame fragmentation, frame aggregation, and protocol conversion.

Read the full article here:
[https://copperhilltech.com/blog/building-a-classical-can-to-can-fd-gateway-with-the-esp32s3/](https://copperhilltech.com/blog/building-a-classical-can-to-can-fd-gateway-with-the-esp32s3/)

07/31/2026

Modern embedded systems are no longer limited by cables. By combining the ESP32-S3's built-in Wi-Fi, Bluetooth, and BLE capabilities with support for both Classical CAN and CAN FD, developers can build powerful wireless gateways for remote diagnostics, Industrial IoT, fleet management, wireless data logging, and cloud-connected applications.

Our latest article explores the architecture behind wireless CAN gateways, discusses the advantages of each wireless technology, and demonstrates how the ESP32-S3 Board with Classical CAN and CAN FD provides an excellent platform for rapid development and prototyping.

Read the full article here:
[https://copperhilltech.com/blog/building-wireless-can-gateways-with-esp32s3/](https://copperhilltech.com/blog/building-wireless-can-gateways-with-esp32s3/)

07/30/2026

**Reduce Manufacturing Test Time with a Programmable J1939 ECU Simulator**

Manufacturing and validating SAE J1939-based products doesn't have to require a complete vehicle or a rack full of ECUs. A programmable **J1939 ECU Simulator** can recreate realistic network conditions, automate repetitive tests, and significantly reduce production and validation time.

In this new article, we explore how the **Copperhill Technologies SAE J1939 ECU Simulator** and the **free JCOM1939 Monitor for Windows** help engineers:

* Replace physical ECUs with programmable simulation
* Automate end-of-line and regression testing
* Simulate complete J1939 network behavior
* Monitor, analyze, and validate J1939 communication in real time
* Improve test repeatability while lowering manufacturing costs

Whether you're developing embedded controllers, gateways, displays, data loggers, or other SAE J1939 devices, this combination provides a powerful solution from development through production.

Read the full article:
[https://jcom1939.com/reducing-manufacturing-test-time-with-a-programmable-j1939-ecu-simulator/](https://jcom1939.com/reducing-manufacturing-test-time-with-a-programmable-j1939-ecu-simulator/)