How Do You Use DMBOTs DM-J4340 Joint Motor?
The DMBOTs DM-J4340 Joint Motor is a high-precision, compact joint module designed for collaborative robots, robotic arms, and automation systems that require precise torque control, compact integration, and real-time communication. In this article, we’ll explain what this joint motor offers, how to use it, and the basic command instructions to get started with development.
Key Features of the DMBOTs DM-J4340 Joint Motor
- Integrated Drive + Encoder + Motor Module: Combines a 40W DC brushless motor, magnetic absolute encoder, and driver into a compact structure.
- High Torque Output: Offers a rated torque of 1.2 Nm and peak torque of 2.6 Nm, making it suitable for precision motion control applications.
- Magnetic Absolute Encoder: Built-in 14-bit MA732 encoder provides accurate positioning with no need for homing on startup.
- RS485 & CAN Dual Communication Support: Compatible with CANopen or custom protocol over RS485, enabling reliable real-time control in complex systems.
- PWM & Pulse Mode Support: Flexible communication for different control systems, including direct PWM input or step/dir signals.
- Compact Size: Outer diameter of 43mm, optimized for robotic joints with tight space requirements.
How to Use the DM-J4340 Joint Motor
Power and Wiring
- Power Supply: DC 24–48V input (recommended 24V).
- Communication Ports: Use CANH/CANL for CAN communication; alternatively use TX/RX for RS485-based UART control.
- Temperature Sensor: The motor includes a built-in 10K NTC thermistor, wired to
MOT_TEMPandGND. - Limit Switches: Two 2mm-pitch connectors (
LW1for min,LW2for max), powered by 12V internally, support 2-wire or NPN 3-wire switches. - SWD Debug Port: 2mm pitch for firmware debugging and updates.
Modes of Communication
- CAN Mode:
- Baud rate: 1Mbps (default, configurable)
- Protocol: CANopen or custom protocol
- RS485 UART Mode:
- Baud rate: 115200 (default)
- Protocol: Modbus-like custom instruction set
Command Examples (UART Mode)
You can send hexadecimal instructions through a USB-to-RS485 adapter or microcontroller UART to control the motor.
Example 1: Enable Motor Output
Command: 0xAA 0x01 0x06 0x01 0x01 0x00 0x00 0x0B
Explanation: Enable motor with ID=1
Example 2: Set Target Position
Command: 0xAA 0x01 0x06 0x03 0x00 0x10 0x27 0x4B
Explanation: Set target position to 10000 (in encoder counts)
Example 3: Set Target Speed
Command: 0xAA 0x01 0x06 0x04 0x00 0x64 0x00 0x6F
Explanation: Set speed to 100 RPM
Note: Commands vary by firmware version. Please refer to the user manual provided by DMBOTs for full register map and control instructions.
Recommended Applications of the DM-J4340 Joint Motor
The DMBOTs DM-J4340 Joint Motor is designed for a wide range of advanced robotic and automation scenarios. Thanks to its compact structure, precise motion control, and versatile communication interfaces, it can be seamlessly integrated into various systems, including but not limited to:
6-DOF Robotic Arms
The DM-J4340 is ideal for building lightweight yet highly functional 6-degree-of-freedom (6-DOF) robotic arms used in automation, manufacturing, and laboratory environments. Its integrated driver and high-resolution encoder simplify wiring and improve positional accuracy, making it perfect for pick-and-place, assembly, and precision operation tasks.
Collaborative Robots (Cobots)
In collaborative robot applications, space-saving and precision control are critical. The DM-J4340’s low-profile design and smooth torque response make it suitable for human-robot interaction environments where safety and responsiveness are top priorities. It supports real-time communication protocols like CANopen, which is commonly used in industrial cobots.
Medical and Inspection Robots
Medical robots require compact actuators with high reliability and low noise. The DM-J4340 meets these needs by offering precise control, smooth motion, and robust feedback through its absolute encoder. It can be used in robotic surgical arms, medical diagnostic machines, and automated specimen handling devices.
AGV/AMR Driving Units
In automated guided vehicles (AGVs) and autonomous mobile robots (AMRs), the DM-J4340 can be used as a wheel hub motor or steering joint actuator. Its ability to respond to high-speed signals and maintain torque stability allows AGVs to navigate accurately and adapt to dynamic route planning.
Joint Modules in Modular Robotics
The compact form factor and plug-and-play architecture of the DM-J4340 make it ideal for modular robots or DIY robot kits. Developers can quickly assemble multi-joint robots without complex cabling or external drivers, significantly reducing prototyping time.
Educational Robotics and Competitions
For STEM education and robotics competitions, the DM-J4340 offers a high-performance yet user-friendly solution. Students and developers can explore real-time control, kinematics, and automation logic using PWM, UART, or CAN protocols. Its robustness and integrated design help teams focus on innovation rather than hardware complexity.
Why Choose the DMBOTs DM-J4340?
- Compact All-in-One Design: Reduces system complexity and simplifies mechanical design.
- High Control Precision: Thanks to the 14-bit encoder and smooth torque output.
- Versatile Communication: Choose from CAN, RS485, PWM, or pulse modes to match your system needs.
- Developer-Friendly: Supports SWD programming, UART debugging, and open communication protocols.
Where to Buy
You can get the DMBOTs DM-J4340 Joint Motor directly from SharingWin:
