Datasheet

Motor Adapter for myRIO

Overview

The Motor Adapter for NI myRIO allows you to easily connect and control either one stepper

motor, two DC motors or two servos independently through the MXP connector on your

myRIO. It has been designed so that no additional circuitry is required to drive motors. The

board uses theAllegro A4973, a powerful full-bridge, bidirectional PWM motor controller - just

supply power and you're on your way!

Servo motors are connected via standard 3-pin headers while DC motors are connected via

6-pin or screw terminal connectors and stepper motors are connected using screw terminals.

PWM signals from the standard myRIO FPGA personality are routed to the DC and servo

motor inputs. Motor 0 Quadrature encoder inputs are routed to the myRIO encoder inputs

and Motor 1 are routed to general purpose digital I/O. Filtered motor voltage and current are

routed back to the myRIO analog inputs to enable real-time monitoring.

Key Features:

 Uses the myRIO Expansion Port (MXP) connector

 Can be use to control 2 DC motors, 1 stepper motor, or 2 RC servos

 Current/voltage sensing and control with over-current protection

 6V-16V input voltage using screw-terminal supply connections

 34-pin female breakout allowing direct user access to signal pins

 Onboard quadature encoder interface to myRIO encoder inputs

 Power LED indicator

Connector Pin-outs

Motor PWR (J6) : DC Motor Power Screw-terminal Block

Pin#

Pin Name

Notes

GND

Negative motor voltage

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Motor Adapter for myRIO Overview The Motor Adapter for NI myRIO allows you to easily connect and control either one stepper motor, two DC motors or two servos independently through the MXP connector on your myRIO. It has been designed so that no additional circuitry is required to drive motors.
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Pin# Pin Name Notes 2 6…16VDC Positive motor voltage, 6-16VDC Motor Encoders (J7, J13) : Encoder Signals Screw-terminal Block Pin# Pin Name Notes 1 ENCB Encoder Phase B 2 ENCA Encoder Phase A Servos PWR (J8): Servo Motor Power Screw-terminal Block Pin# Pin Name Description 1 SVDC Positive Servo Motor voltage, 4.
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proper terminals. Alternatively, connect your DC motor(s) to the screw terminals (J4 and/or J5) and if using encoders, wire signals to J7/J13. Connect motor power (16V max) to the Motor Power screw-terminals (J6). Motor direction is controlled by setting myRIO “DIR0” or “DIR1” pin HIGH or LOW and speed/torque is controlled by setting the duty cycle on the myRIO PWM0 and/or PWM1 pins. The A4973 driver has been configured for a 1.5A max current (at 100% duty cycle).