Understanding the Need for 120 Ohm Termination Resistors in CAN Bus Systems

Understanding the Need for 120 Ohm Termination Resistors in CAN Bus Systems

Friends in “Vehicle Technology” should know that the CAN bus requires two 120 Ohm termination resistors at both ends, making the total line resistance 60 Ohms. This is a piece of knowledge that almost everyone knows, but very few can explain clearly. In most cases, we have the experience that adding a 120 Ohm resistor … Read more

Detailed Development of MPC574xP Series MCU Bootloader Based on CAN Bus Communication

Detailed Development of MPC574xP Series MCU Bootloader Based on CAN Bus Communication

Abstract Introduction 1. Bootloader and Application Program Memory Address Allocation for MPC5744P 1.1 SRAM Resources of MPC574xP Series MCU 1.2 Flash Resources of MPC574xP Series MCU 1.3 CAN Bus Bootloader and Application Program Memory Address Allocation for MPC5744P 2. Flash Driver Development (Installation, Downloading, and Using C55 Flash SSD) 3. FlexCAN Driver Development 3.1 DEVKIT-MPC5744P … Read more

What Is an ECU? Causes of Errors and High Load

What Is an ECU? Causes of Errors and High Load

What Is an ECU? ECU, or Electronic Control Unit, also known as the “onboard computer”, is essentially a microcontroller for automobiles. It is composed of a microprocessor, memory, input/output interfaces, analog-to-digital converters, and other large-scale integrated circuits, similar to a regular computer. In simple terms, the ECU is the “brain” of the car. It is … Read more

Troubleshooting Car Navigation System Failure

Troubleshooting Car Navigation System Failure

Fault Phenomenon A 2017 Mercedes-Benz V260L vehicle, equipped with a 2.0T engine, has a navigation system with version number NTG5.2 of the COMAND (Cockpit Management and Data) system, with a total mileage of approximately 35,000 km. The owner reports that the COMAND display is black, with no display or sound, and all the system’s switch … Read more

Practical 16-Bit External Bus Expansion for 8-Bit Microcontrollers

Practical 16-Bit External Bus Expansion for 8-Bit Microcontrollers

1 8-Bit/16-Bit Bus Timing Analysis 1.1 8-Bit Microcontroller Bus Timing There are many 8-bit microcontrollers with external buses, such as the 51 series and AVR series. This article takes the W77E58 as an example. The W77E58 is an enhanced 51 microcontroller introduced by Winbond, with a maximum operating clock of 40 MHz. At the same … Read more

Selected System Design: FPGA-Based CAN Bus Controller Design

Today, I bring you the design of a CAN bus controller based on FPGA. Due to the lengthy content, it is divided into three parts. Today, I present the third part, followed by the next one, which covers the program simulation and testing, as well as a summary. Without further ado, let’s get started. I … Read more

Why Is the CAN Bus Termination Resistor 120Ω?

Why Is the CAN Bus Termination Resistor 120Ω?

Source | Vehicle Terminal Function of the Termination Resistor The CAN bus termination resistor serves three purposes: 1. Enhance anti-interference capability, allowing high-frequency low-energy signals to dissipate quickly. 2. Ensure the bus quickly enters a dormant state, allowing the energy of parasitic capacitance to dissipate faster; 3. Improve signal quality, placed at both ends of … Read more

Detailed Explanation of Automotive CAN Bus Technology

Detailed Explanation of Automotive CAN Bus Technology

Editor ▎ Wang Yan Review ▎Yu Yongchu Jinfen Mall Popular Book Rankings ☞ Jinfen’s Favorite Book Rankings ☞ Mechanical Book Rankings ☞ Production Management Rankings ☞ Design Software Rankings How to Quickly Publish Articles in the ‘Automotive Engineer’ Magazine October 2022 Automotive Production and Sales: Continued Year-on-Year Growth, New Energy Vehicles Set New Historical Highs … Read more

Differences Between RS-485 and CAN-bus

Differences Between RS-485 and CAN-bus

In bus systems, both RS-485 and CAN-bus are commonly used buses, each with unique characteristics and application scenarios, widely applied. Today, let’s discuss their differences. 1. What is RS-485? RS-485 is a serial communication protocol that has been around since the mid-1980s, originally defined for industrial market applications. It uses differential signaling with negative logic, … Read more

Regular Maintenance Methods for CAN Bus Faults – Part 1

Regular Maintenance Methods for CAN Bus Faults - Part 1

When the CAN bus malfunctions or data transmission is abnormal, various strange fault phenomena often occur, such as abnormal dashboard displays, inability to start the vehicle, failure to turn off after starting, decreased vehicle performance, and loss of certain electronic control system functions. This is because relevant data or information is transmitted through the CAN … Read more