Herkulex DRS-0101 Smart Servo

The Herkulex DRS-0101 is a smart servo from Dongbu Robot that integrates a DC motor, a planetary gear reducer, control circuitry, and serial communications into a single compact module. It delivers 12 kgf.cm of stall torque at 7.4 V through a 1:266 Super Engineering Plastic gear train, with a 320 degree range plus support for a full continuous rotation mode. Communication uses a full-duplex asynchronous TTL serial bus (binary packet protocol, multi-drop) at baud rates up to 667 kbps, allowing up to 254 servos to share a single bus via unique IDs. Onboard sensors return real-time position, speed, load, temperature, and supply voltage, while seven built-in error types are flagged via a user-programmable RGB LED. Control algorithms running on the internal MCU include PID, feedforward, trapezoidal velocity profiling, torque saturation, overload protection, and dead-zone compensation. The DRS-0101 is commonly used in small humanoid robot joints, robotic arms, pan-tilt heads, and any multi-axis platform requiring closed-loop position and speed control with daisy-chain wiring.