3A Motor Controller with Feedback

SKU : 3AMCwF

The 3-Amp motor controller with multiple interface and feedback options simplifies servo control of commonly available DC motors. The module features three independent interfaces: a serial protocol for microcontroller-based applications, a pulse-width interface for connection to hobby radio control equipment or serial servo controllers, and an analog voltage interface for simple tests and demonstrations. Two feedback alternatives allows for closed-loop control of position or speed. A higher-power version,SMC04 high-power motor controller with feedback, is also available.

This motor controller distinguishes itself from other devices in its class by offering a complete feedback-based solution for applications requiring bi-directional, closed-loop control. The user can select either an analog voltage feedback or a digital encoder feedback (quadrature encoding is not supported). With the two feedback alternatives, various simple devices such as potentiometers can be used as sensors to achieve position or speed control.

In a typical application, a user first sets up the motor controller’s parameters based on the physical properties of the mechanical system that is being driven. A feedback potentiometer is coupled to the mechanism output, and the user can then send position commands to the motor controller, which automatically drives the motor to reach the position. Alternatively, the mechanism and sensor can be arranged to provide speed feedback, in which case the motor controller maintains given speeds despite fluctuations in friction or supply voltage.

The motor controller measures 1.4" x 1.4" and has an operating voltage of 6–18 volts, making the device well-suited for small robots and other projects using toy motors and rechargeable 7.2 V or 9.6 V battery packs. The motor controller serial protocol is compatible with other Pololu motion control devices, allowing multiple units to be connected to a single serial line to control a mixture of motors sizes and hobby RC servos.

What do the red and green LEDs indicate?

The LEDs indicate different things depending on the mode (set by the two jumpers):

     - feedback modes:

        - red on: motor speed at max

        - green on: error magnitude less than or equal to 1

        (In RC mode, both LEDs on for no signal)

        (In serial mode, red or green light flashes for serial too slow or to fast)

     - serial input, no feedback

        - red LED: motor error

        - green LED: on if motor speed not 0

     - RC input, no feedback

        - red LED on: bad RC signal

        - green LED on: good RC signal

        - analog input, no feedback

        - red LED for one direction, green LED for other direction