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

The ST3215 is a high-performance 12V serial bus servo engineered for complex mechatronics and multi-axis robotics. Delivering 30kg.cm of stall torque with 360-degree absolute magnetic encoding, it provides precise position feedback and daisy-chain control over a single TTL serial bus. It is an ideal actuator for robotics students, educators, and makers building articulated arms, quadruped walkers, and humanoid platforms.

High-resolution magnetic encoder feedback

A 12-bit non-contact magnetic encoder provides 360-degree absolute positioning across 4096 steps with 0.088-degree control resolution. The wear-free sensing architecture ensures extended operational life and supports one-click midpoint calibration to establish a custom centre point at any angle.

Robust high-torque metal drivetrain

Driven by a responsive 12V coreless motor, the servo produces 30kg.cm of stall torque through an internal 1:345 copper and aluminium gear train. The mechanism is enclosed in a rigid glass-fibre reinforced polyamide housing with ball bearings to deliver durable, low-noise operation under heavy loads.

Daisy-chain serial bus telemetry

A half-duplex TTL UART protocol allows up to 253 servos to be daisy-chained on a single serial line, drastically cutting down on wiring complexity. The bi-directional bus transmits control commands while providing real-time feedback on position, speed, load, voltage, current, and operating temperature.

Four adaptable operational modes

The servo can operate in standard Angle Servo mode for 0 to 360-degree positioning, Speed Closed-loop mode to maintain constant velocity under changing loads, Speed Open-loop mode, or Stepping mode for incremental motion. It also supports multi-turn positioning up to plus or minus seven full rotations.

Comprehensive electronic safety protections

Built-in electronic safeguards protect against overload, overcurrent, out-of-range voltage, and overheating beyond 70 degrees Celsius. Configurable acceleration and deceleration parameters further protect the mechanism by delivering smooth motion profiles that reduce mechanical shock.

Broad mechatronic application support

With high holding torque, daisy-chain connectivity, and closed-loop feedback, this servo is tailored for multi-DOF robotic arms, quadruped robots, and humanoid platforms. It is equally suited for small-scale sorting conveyors and educational automation testbenches.