Overview

The RoboClaws from Basicmicro are a family of efficient, versatile, synchronous regenerative motor controllers. They can supply brushed DC motors with 7.5 A, 15 A, 30 A, 45 A, 60 A, 120 A, or 300 A continuous (depending on the model) at voltages from 6 V to 34 V, 6 V to 60 V, or 10.5 V to 60 V (also depending on the model), and they allow for peak currents well above the maximum continuous ratings. The “Solo” versions feature a single motor control channel while the dual versions (denoted by a “2x” in their names) offer two channels for controlling a pair of motors.

The RoboClaws have a USB interface that acts as a virtual serial (COM) port, allowing it to be controlled directly from a computer, and they feature built-in commands for controlling acceleration, deceleration, distance, speed, current sense, voltage limits and more. Several other interface modes are supported by the RoboClaw as well: it can be controlled via TTL serial for use with embedded systems, RC hobby servo pulses for use as an RC-controlled electronic speed control (ESC), or analog voltages for use with potentiometers or analog joysticks.

RoboClaw automatically supports 3.3V or 5V logic levels, travel limit switches, home switches, emergency stop switches, power supplies, braking systems and contactors. Power supplies can be used by enabling the built in voltage clamping control feature. A built-in switching mode BEC supplies 5VDC at up to 1.2 A or 3 A (depending on controller model) for powering user devices.

The RoboClaws can be operated without feedback for open-loop speed control, or they can be used with a variety of feedback types for closed-loop speed or position control. Quadrature encoders with up to 19.6 million pulses per second are supported and can be auto tuned using Motion Studio, which is a free downloadable application. In addition, a wide range of sensor inputs such as potentiometers and absolute encoders are supported. RoboClaw’s closed loop functionality creates absolute control over speed and direction regardless of load changes.

RoboClaw incorporates several protection features including temperature, current, over voltage and under voltage limits. Several user definable settings such as maximum current limit, maximum and minimum battery voltages are provided for more refined control. The controller uses regenerative braking but can be configured with a voltage clamp circuit to limit the regenerative voltage when used with switching power supplies. The Basicmicro VClamp is a voltage clamp specifically designed to work with the RoboClaw and MCP to suppress such voltage spikes and is rated for use with supplies up to 60 V and currents up to 60 A.

Key features of the RoboClaw family

• Simple bidirectional control of one or two brushed DC motors, depending on controller model
• 6 V to 34 V, 6 V to 60 V, or 10.5 V to 60 V operating supply range, depending on controller model
• 7.5 A to 300 A maximum continuous current output, depending on controller model
• Dual-channel controllers support channel bridging to allow control of a single motor with double the current capability
• Automatic current limiting reduces duty cycle when temperature exceeds 85° C
• Four communication or control options:
  1. USB serial interface (virtual COM port)
  2. Logic-level (TTL) serial interface for direct connection to microcontrollers or other embedded controllers
  3. Hobby radio control (RC) pulse width interface for direct connection to an RC receiver or RC servo controller
  4. Analog voltage (0 V to 2 V, 5 V tolerant) interface for direct connection to potentiometers and analog joysticks
• Dual feedback inputs for PID closed-loop control:
  • Speed or position control with quadrature encoders, up to 19.6 million encoder pulses per second
  • Position control with analog encoders or potentiometers
  • (Open-loop control with no feedback also available)
• Screw terminals for quick connect/disconnect
• Configurable via pushbutton interface or USB connection and PC software
• Regenerative braking
• Tolerates high-speed direction changes
• Jumper-selectable 5 V BEC
• Battery monitoring and under-voltage cutoff protects batteries from over-discharging
• RoboClaw user manual