The UART serial bus servo is a two-way communication servo. User can customize the operation modes, feedback data, velocity control algorithms and protections. SDK is also provided to fulfill the development under various platforms.

Basic Features

Model: RA8-U25 | HA8-U25 

  •  32-Bit MCU
  •  Stall Torque: 25Kg-cm (7.4V)
  •  No-load Speed: 0.15sec@60º (7.4V)
  •  Operation Voltage: 6.0-8.4V
  •  Travel Angle: 180º | 270º
  •  Enhanced Shaft Gear
  •  Cored Motor 
  •  Dual Shaft (RA8 Series)
  •  Single Shaft (HA8 Series)


UART servos, each assigned with an ID at first,  are connected in a bus channel. They communicate through a half-duplex asynchronous serial communication protocol. And the data can be exchanged with a full-duplex communication protocol through extension boards.

Physical Features

We strive to pursue the accuracy and reliability of every part in detail.

Convertors & Shields

Varieties of convertors and shields provide you easy access to use UART serial bus servo on different platforms.

Configuration Software

  • Provides easy access to view and customize the parameters
  • Setting servo ID, baud rate and protections
  • Get the data from servo on line
  • Online simulate 3 working mode
  • Restore the factory default setting
User Manual

Flexible Assembly

  • Body mounting holes adopts full symmetric structure (Dual-shaft servo only)
  • The brackets can be installed from -90º, 0º and 90º direction
  • Sunken horn plate design
  • (Sold Separately)

What’s included

  • Master horn plate (25T)                         1pcs
  • Slave horn plate                                           1pcs
  • M3.0*6                                                              2pcs
  • M2.0*5                                                           16pcs
  • PB2.0*5                                                         10pcs
  • PH2.0 cable (20cm)                                   1pcs

Product Code

RA8-U25 | HA8-U25

Configuration Software User Manual

Latest updated   2019-10-12

Configuration Software(Windows)

1.2MB   2019-10-12

Servo 3D/CAD Drawings

477KB   2019-10-12

Horn Plate 3D/CAD Drawings

510KB   2019-10-12