Qt Canopen Master

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QCanopenMaster

QCanopenMaster is a lightweight CANopen master component based on Qt. It encapsulates core functionalities such as device drivers, NMT management, heartbeat monitoring, and SDO access. It provides a simple and consistent QObject/QML-friendly interface for easy and fast integration into Qt applications.

• Language/Framework: C++17 / Qt 5/6 (based on QtCore)
• Build System: CMake
• Suitable Scenarios: CANopen master control, device debugging, upper computer tools, automated testing

Features

• Singleton management: QCanopenMaster::instance() global unique instance
• Device lifecycle: initDevice / openDevice / closeDevice / resetCanDevice
• Master periodic task: process() can be driven by external timer
• NMT control: Start / Stop / Pre-Operational / Reset Node / Reset Communication
• SDO access: read (uploadSDO) and write (downloadSDO)
• Raw CAN frame sending: sendRequest
• Event signals: error reporting, CAN frame reporting, SDO result reporting
• Q_INVOKABLE: easy to call directly from QML/Qt meta-object system

Directory Structure

• QCanopenMaster_global.h: export macro definitions
• qcanopenmaster.h / .cpp: main class and external API
• CanOpen/
  • driver.*: underlying CAN driver abstraction
  • NMT.*: NMT management
  • heartBeat.*: heartbeat monitoring
  • SDO.*: SDO access implementation
  • canopenObject.*: object dictionary/device abstraction
• utils/
  • ByteParser.*: byte order and parsing utilities

Dependencies and Environment

• Qt 5.15+ or Qt 6.x (QtCore required)
• CMake 3.16+
• C++17 compiler
• Platform support depends on driver implementation (example parameters include SocketCAN, usable on Linux; Windows requires corresponding CAN driver support)

API

Device Management

• setCurrentNodeId(uint8_t nodeId)
  Set the current working node ID.

• initDevice(QVariantMap params)
  Initialize the device. Example parameters:

  { "canType": "SocketCan", "channel": "0", "nominalBaudrate": "500000", "dataBaudrate": "2000000" }

• openDevice()
  Open the device connection.

• closeDevice()
  Close the device connection.

• resetCanDevice()
  Reset the device.

Communication and Control

• sendRequest(QVariantMap params)
  Send original CAN frame, example:

  {
      "canId": 1537,
      "dlc": 4,
      "data": [11, 22, 33, 44, 55, 66, 77, 88],
      "time": 1723267200000
    }

• sendNMT(uint8_t command)
  Send NMT instruction:
  • 0x01 Start
  • 0x02 Stop
  • 0x80 Pre-Operational
  • 0x81 Reset Node
  • 0x82 Reset Communication

SDO Visit

• uploadSDO(uint16_t nodeId, uint16_t index, uint8_t subIndex, QVariant data)
  Read object dictionary data.

• downloadSDO(uint16_t nodeId, uint16_t index, uint8_t subIndex, QVariant data)
  Write object dictionary data.

• resetSDOState()
  Reset the SDO state machine.

Signal

• sendErrorSig(QString error)
  Error message reporting.

• sendCanFrameToUiSig(QVariantMap item)
  Report to the UI when CAN frames are received and sent.

• sendSdoItemSig(uint16_t nodeId, uint16_t index, uint8_t subIndex, QVariantMap sdoItem)
  Report when SDO data is received.

License

This project is open-sourced under the MIT License.
Please refer to the LICENSE file in the repository root for details.
When using this project’s code, please comply with the license terms.