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ST3215 Serial Bus Servo (12V, 30kg, 360° Magnetic Encoder)

$19.90
SKU: SER0070
The ST3215 is a 12V serial bus servo delivering 30kg.cm of stall torque. It features a 12-bit high-precision magnetic encoder for 360° absolute positioning (0.088° resolution). Control up to 253 servos via a half-duplex UART interface. Provides real-time feedback on position, load, voltage, and temperature. Includes four operating modes and multiple electronic protections.
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Introduction

The ST3215 is a high-performance, intelligent serial bus servo engineered for advanced robotics and automation. Operating at 12V, it delivers a substantial 30kg.cm of torque, driven by a durable coreless motor and a high-strength metal gear train. Its core technology is a 12-bit high-precision magnetic encoder, which enables 360° absolute positioning with a resolution of 0.088°, offering superior accuracy and lifespan compared to traditional potentiometers. Communication is handled via a half-duplex UART serial bus, allowing up to 253 servos to be daisy-chained on a single port for simplified wiring and bi-directional data feedback. With four distinct operating modes, comprehensive electronic protections, and real-time parameter feedback, the ST3215 is an ideal solution for building complex robotic arms, quadruped robots, humanoid robots, and other sophisticated mechatronic systems.


360° High-Precision Magnetic Encoder

At the heart of the ST3215 serial bus servo is a 12-bit magnetic encoder that provides absolute position feedback over a full 360° range. With 4096 steps of resolution, it achieves a control accuracy of 0.088°, which is four times the resolution of conventional potentiometers. This non-contact sensing technology eliminates physical wear, leading to a much longer operational life. A key feature is the one-click midpoint calibration, allowing any position within the 360° range to be set as the new center point, greatly simplifying installation and maintenance.


High Torque & Durable Metal Gear Design

Engineered for demanding loads, the ST3215 serial bus servo provides a stall torque of 30kg.cm. The internal 1:345 gear train is constructed from a combination of copper and aluminum, ensuring high strength and low operational noise. Housed in a robust PA+GF casing, the servo is designed for reliability and longevity in applications requiring significant force and continuous operation.


Four Versatile Operating Modes

To accommodate a wide variety of applications, the ST3215 serial bus servo is equipped with four distinct operational modes.

  • Angle Servo Mode: The default mode for precise 0-360° absolute positioning with a configurable acceleration and deceleration function for smoother movements.
  • Speed Closed-loop Motor Mode: The servo functions as a DC motor, maintaining a constant speed even when the load changes.
  • Speed Open-loop Motor Mode: Functions as a standard DC motor where speed is proportional to voltage and will decrease under load.
  • Stepping Mode: Allows for incremental motion from the current position and supports continuous rotation, emulating the behavior of a stepper motor.

  • Intelligent Serial Bus Communication

    The ST3215 serial bus servo utilizes a TTL-level UART serial bus protocol, which enables daisy-chaining of up to 253 servos. This architecture drastically reduces wiring complexity in multi-axis robotic systems. The bus supports bi-directional communication, allowing not only for command execution but also for real-time feedback of critical parameters, including position, speed, load, voltage, and temperature. This capability is essential for creating closed-loop control systems and monitoring the health of the entire robotic assembly.


    High-Precision Magnetic Encoder and Four Operating Modes


    Advanced Control and Comprehensive Protection

    The ST3215 serial bus servo integrates a suite of advanced features to ensure reliable and safe operation. The configurable acceleration start/stop function creates a smoother and more natural motion profile, reducing mechanical shock. Furthermore, built-in electronic protections guard against overload, overcurrent, overvoltage, and overheating conditions. These protections are customizable and automatically trigger to prevent damage to the servo, enhancing the overall system's robustness.

    New Step Mode, Multi-Turn Large-Angle Precise Control and One-Key Center Calibration

    Dual-Axis, Low-Profile Housing with Metal Gear Structure and Metal Servo Horn

    Applications

  • Robotic arms
  • Educational robots
  • Quadruped robots
  • Humanoid robots
  • Small-scale sorting systems
  • Specification

    Electrical Characteristics

  • Rated working voltage: 12V
  • No-load speed: 0.222s/60° (45RPM)
  • No-load current: 180mA
  • Stall torque: 30kg.cm/417.35oz.in
  • Stall current: 2.7A
  • Standby current: 30mA
  • Operating voltage: 4-14V
  • Rated load: 10kg.cm
  • Rated current: 900mA
  • Motor resistance: 1Ω
  • Torque constant (Kt): 11kg.cm/A
  • Mechanical Specifications

  • Dimensions: 45.2×24.7×35mm
  • Housing: PA+GF
  • Gear material: Copper
  • Bearing: Ball bearing
  • Sensor: 12-bit magnetic encoder
  • Rotation: 360°
  • Connector: 3-pin (Black-GND, Red-VCC, Blue-Signal/TTL)
  • Cable length: 15cm
  • Weight: 55±1g
  • Output shaft: 25T/OD5.9mm
  • Gear ratio: 1:345
  • Gear backlash: ≤0.5°
  • Output shaft screw: M3×6
  • Motor type: Coreless
  • Control Characteristics

  • Signal: Digital
  • Protocol: Half-duplex UART (8-bit, 1 stop bit, no parity)
  • ID range: 0-253
  • Baud rate: 38.4kbps-1Mbps (default: 1Mbps)
  • Control algorithm: PID
  • Midpoint: 180° (2048 steps)
  • Resolution: 0.088°
  • Rotation direction: Clockwise (0→4096)
  • Feedback: Load, position, operating speed, input voltage, operating current, operating temperature
  • Electronic Protection:
             Overload: Triggers when stalled torque exceeds 80% of stall value for 2s; cleared by sending new position command. Customizable torque threshold/duration.
             Overcurrent: Disables output when current >2A for 2s; cleared by sending new position command. Customizable current threshold/duration.
             Overvoltage: Activates when voltage >7.4V or <4V; auto-recovery within normal range. Customizable voltage range.
             Overheat: Disables torque output when temperature >70°C.
  • Operating Modes:
             Mode 0: Angle Servo (default; 0-360° absolute positioning)
             Mode 1: Speed Closed-loop Motor (maintains speed under load)
             Mode 2: Speed Open-loop Motor (speed drops under load)
             Mode 3: Stepping Mode (incremental motion from current position)
  • Multi-Turn Mode: ±7-turn absolute positioning at maximum precision (turn count not saved after power loss).
  • Center Calibration: One-click midpoint setting at any 360° position.
  • Reliability Testing

  • Load lifespan: >100,000 cycles
  • Motor noise: 45±5dB
  • Servo noise: 65±5dB
  • Storage temp: -30°C to +80°C
  • Operating temp: -10°C to +60°C
  • Signal Parameters

  • Max update rate: 1ms
  • High-level voltage: 2-5V
  • Low-level voltage: 0-0.45V
  • Documents

    Shipping List

  • ST3215 Serial Bus Servo-12V 30kg 360° ×1
  • Servo horn screw accessory kit ×1
  • 3-pin servo cable ×1
  • ST3215 Serial Bus Servo (12V, 30kg, 360° Magnetic Encoder)
    $0.00