Waveshare has recently launched DDSM Driver HAT (B), a compact Raspberry Pi DDSM (Direct Drive Servo Motor) motor driver designed specifically to drive the DDSM400 hub motors. This board is built around an ESP32 MCU and supports wired (USB and UART) and wireless (2.4GHz WiFi) communication.
Additionally, the board features a physical toggle switch, which lets it choose between the ESP32 control or USB control modes. On ESP32 control mode you can control the device through a built-in web application. In the USB control mode, the motor driver can be controlled via USB from a host computer sending JSON commands. An XT60 connector is used to power the board, and programming is done through a USB-C port that connects to the ESP32. The board is suitable for robotics projects, especially for mobile robots in 6×6 or 4×4 configurations.
Waveshare DDSM Driver HAT (B) specifications:
- Wireless MCU – Espressif Systems ESP32-WROOM-32E
- ESP32 dual-core Tensilica LX6 microcontroller
- Storage – 4MB flash
- Wireless 2.4 GHz WiFi and Bluetooth LE connectivity, built-in PCB antenna
- Supported host controller (one or the other) – Raspberry Pi 5 or Raspberry Pi 4B
- Control Modes
- Wired – USB, UART
- Wireless – Web application (Cross-platform support for mobile, tablet, PC)
- Motor Drivers – Onboard 6-channel motor interfaces (for up to 6x DDSM400 hub motors)
- Host Interface – Communicates with Raspberry Pi through UART
- USB
- 1x USB-C port for programming the ESP32 module
- 1x USB-C port for controlling the HUB motors
- Misc – Reset and BOOT buttons
- Power Supply-
- 9V ~ 28V DC via XT60 5.5 x 2.5mm power jack
- Powers the Raspberry Pi via integrated 5V buck regulator
- Dimensions
- PCB Dimensions – 85 x 57 mm
- Mounting Hole Diameter – 3 mm
- Mounting Hole Spacing – 58 x 49 mm
The DDSM400 Direct Drive Servo Motor is a compact, all-in-one hub motor designed for RC cars, robots, and automation. Its direct drive design eliminates reducers, offering zero backlash, low noise, and 99.99% efficiency. It combines a PMSM, encoder, and servo, operating from 100 RPM (rated torque) to 400 RPM (no-load). With LIN bus communication, it supports multi-motor control and real-time feedback on position, speed, and more. Durable with IP54 protection, it’s easy to integrate with robot chassis or UGV suspensions, making it perfect for precise, efficient applications.
Waveshare provides various tools and software to control the DDSM400 hub motors. The motor driver board comes with factory-loaded ESP32 firmware (see Arduino code), which allows users to control the motors via a web application or wired connections using JSON commands. These commands let users set motor IDs, enable or disable motors, switch modes, and control speed. Additionally, users can upload custom firmware to the ESP32 for more advanced control features. The board also supports ESP-NOW for remote communication and control, along with different Python scripts for more control and serial debugging tools for troubleshooting. More information on this topic can be found on the Wiki.
Other Raspberry Pi HAT for motor control include the Adeept Robot HAT motor and sensor driver HAT, and the Serial Bus Servo Driver HAT (A) from Waveshare which can drive up to 253 serial servos simultaneously. The Waveshare DDSM Driver HAT (B) is the first DDSM HAT we’ve covered CNX Software, and even the first product related to direct drive servo motors.
The DDSM Driver HAT (B) is available on both Amazon for $31.99 and AliExpress for $22.60. You’ll probably want to get some DDSM400 hub motors too, and they can be also found on Amazon ($37.99) or AliExpress ($27.89). You’ll also find suspensions for the hub motors on either store.
Debashis Das is a technical content writer and embedded engineer with over five years of experience in the industry. With expertise in Embedded C, PCB Design, and SEO optimization, he effectively blends difficult technical topics with clear communication
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