Description
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.
Position Mode
The position is controlled in unit “degree” with a minimum step of 0.1º. No ADC converting needed.
Wheel Mode
Max no-load speed is 700º/sec. The number and time of the rotations can be set separately.
Locking Force Mode
While maintaining a certain output locking force, the angular position can be changed with external force.
Power Control
The maximum output power of the servo can be limited, and the current power data can be fed back in real time.
Velocity Control Algorithm
Provide smoother motion trajectory control during the servo start and brake phases.
Baud Rate Configuration
The baud rate can be modified from 9600-1Mbps to be compatible with different 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)
Protocols
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.

UC-01
USB/TTL Convertor
- Communicate with PC
- Micro-USB Support
- 5V voltage regulator circuit
- Reverse protection


Rasprobo2
Raspberry Pi Shield
- Integrated IMU module
- Integrated light enhanced module
- I2C&IO Interface
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


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
