How to Use USB to CAN Adapter: Examples, Pinouts, and Specs

The DSD TECH SH-C31A USB to CAN Adapter with FD Support, based on the Canable 2.0 design, is a versatile device that bridges the gap between a USB port on a computer and a Controller Area Network (CAN). This adapter enables seamless communication, data transfer, and control of CAN devices, making it an essential tool for automotive diagnostics, industrial automation, and embedded system development.

• Automotive diagnostics and debugging
• Industrial automation and control systems
• Embedded system development and testing
• Real-time monitoring of CAN bus data
• Prototyping and development of CAN-based devices

The following table outlines the key technical details of the SH-C31A USB to CAN Adapter:

The SH-C31A USB to CAN Adapter features a DB9 connector for CAN communication. The pinout is as follows:

1. Connect the Adapter to a Computer: Plug the USB connector into an available USB port on your computer.
2. Install Drivers:
   • For Windows, download and install the appropriate drivers from the DSD TECH website.
   • For Linux and macOS, the adapter is typically recognized as a USB-CAN device without additional drivers.
3. Connect to the CAN Bus:
   • Use the DB9 connector to interface with the CAN bus.
   • Connect CAN_H to the CAN High line and CAN_L to the CAN Low line of your CAN network.
4. Configure the Adapter:
   • Use software tools like candlelight, CANable GUI, or SocketCAN (Linux) to configure the baud rate and other parameters.
5. Monitor and Transmit Data:
   • Use compatible software to monitor CAN messages or transmit data to the CAN bus.

• Termination Resistor: Ensure that the CAN bus is properly terminated with 120-ohm resistors at both ends of the bus.
• Power Supply: The adapter is powered via USB, so no external power supply is required.
• Firmware Updates: Check for firmware updates on the DSD TECH website to ensure compatibility with the latest CAN standards.
• Isolation: The SH-C31A does not provide galvanic isolation. For high-voltage environments, consider using an isolated USB to CAN adapter.

The SH-C31A can be used with an Arduino UNO to monitor CAN messages. Below is an example of how to set up the adapter with the Arduino IDE:

#include <SPI.h>
#include <mcp2515.h> // Include the MCP2515 CAN library

MCP2515 mcp2515(10); // Set the CS pin to 10 for the MCP2515 CAN controller

void setup() {
  Serial.begin(9600); // Initialize serial communication
  SPI.begin();        // Initialize SPI communication

  // Initialize the MCP2515 CAN controller
  if (mcp2515.reset() != MCP2515::ERROR_OK) {
    Serial.println("MCP2515 reset failed!");
    while (1);
  }

  // Set the CAN speed to 500 kbps
  if (mcp2515.setBitrate(CAN_500KBPS) != MCP2515::ERROR_OK) {
    Serial.println("Failed to set CAN bitrate!");
    while (1);
  }

  // Set the MCP2515 to normal mode
  if (mcp2515.setNormalMode() != MCP2515::ERROR_OK) {
    Serial.println("Failed to set normal mode!");
    while (1);
  }

  Serial.println("MCP2515 initialized successfully!");
}

void loop() {
  CAN_message_t message;

  // Check if a new CAN message is available
  if (mcp2515.readMessage(&message) == MCP2515::ERROR_OK) {
    Serial.print("Message ID: ");
    Serial.println(message.id, HEX);

    Serial.print("Data: ");
    for (int i = 0; i < message.len; i++) {
      Serial.print(message.data[i], HEX);
      Serial.print(" ");
    }
    Serial.println();
  }
}

• Ensure the MCP2515 CAN module is connected to the Arduino UNO.
• The SH-C31A adapter can be used to monitor the CAN bus activity generated by the Arduino.

1. Adapter Not Recognized by the Computer:

   • Ensure the USB cable is properly connected.
   • Install the correct drivers for your operating system.
   • Try a different USB port or cable.

2. No CAN Messages Detected:

   • Verify the CAN bus wiring and ensure proper termination with 120-ohm resistors.
   • Check the baud rate configuration of the adapter and the CAN network.

3. Data Corruption or Errors:

   • Ensure the CAN_H and CAN_L lines are not swapped.
   • Avoid long or improperly shielded cables that may introduce noise.

4. Firmware Update Issues:

   • Follow the firmware update instructions provided by DSD TECH carefully.
   • Ensure the adapter is not disconnected during the update process.

Q: Can the SH-C31A be used with Raspberry Pi?
A: Yes, the adapter is compatible with Raspberry Pi using the SocketCAN interface on Linux.

Q: Does the adapter support CAN FD?
A: Yes, the SH-C31A supports CAN FD with data rates up to 8 Mbps.

Q: Is the adapter compatible with third-party CAN software?
A: Yes, it works with popular tools like candlelight, CANable GUI, and SocketCAN.

Q: Can I use the adapter for automotive diagnostics?
A: Yes, the SH-C31A is suitable for automotive diagnostics, provided the software supports the required protocols.