Motor Control

Currently supports the following types of motors:

Motor controller boards with just two separate PWM connections; one for forwards / clockwise control, the other for backwards / ant-clockwise control. Examples: CamJam EduKit #3 Robotics Kit, Ryanteck RPi Motor Controller Board.
H-Bridge style motor drivers with three connections; PWM proportionate control, digital forwards / clockwise control, and digital backwards / anti-clockwise control. Examples: Toshiba TB6612FNG Dual Motor Driver.
Servos

API

MotorInterface

interface com.diozero.api.motor.MotorInterface source ¶

Represents a single motor.

forward (speed=1)

: Turn the motor forward at the specified speed (range 0..1).

speed (float) - Speed, range 0..1. Defaults to 1.

backward (speed=1)

: Turn the motor backward at the specified speed (range 0..1).

speed (float) - Speed, range 0..1. Defaults to 1.

stop ()

: Stop the motor.

reverse ()

: Reverse the direction of the motor.

float getValue ()

: Get the current motor direction and speed, between -1 (full speed backward) and 1 (full speed forward).

setValue (value)

: Set the motor direction and speed.

value (float) - Relative value between -1 (full speed backward) and 1 (full speed forward).

boolean isActive ()

: Return true if the motor is moving in either direction, false if stopped.

whenForward (action)

: Action to perform when going forward

action (Action) - Callback action object

whenBackward (action)

: Action to perform when going backward

action (Action) - Callback action object

whenStop (action)

: Action to perform when stopped

action (Action) - Callback action object

addListener (listener)

: Listener to be notified when the motor value changes

listener (MotorListener) - Listener instance

removeListener (listener)

: Remove a listener

listener (MotorListener) - Listener instance

MotorBase

interface com.diozero.api.motor.MotorBase source ¶

Base motor class, support for events. Implements MotorInterface.

MotorBase ()

: Constructor.

reverse ()

: Reverse the direction of the motor.

setValue (value)

: Set the motor direction and speed.

value (float) - Range -1..1. Negative numbers backward.

whenForward (action)

: Action to perform when going forward

action (Action) - Callback action object

whenBackward (action)

: Action to perform when going backward

action (Action) - Callback action object

whenStop (action)

: Action to perform when stopped

action (Action) - Callback action object

addListener (listener)

: Listener to be notified when the motor value changes

listener (MotorListener) - Listener instance

removeListener (listener)

: Remove a listener

listener (MotorListener) - Listener instance

Digital Motor

class com.diozero.api.motor.DigitalMotor (forwardGpio, backwardGpio) source ¶

Represents a single motor controlled by two separate digital signals. Extends MotorBase.

forwardGpio (int) - GPIO for forward / clockwise control.
backwardGpio (int) - GPIO for backward / anti-clockwise control.

forward ()

: Stop the backward motor and turn on the forward motor.

backward ()

: Stop the forward motor and turn on the backward motor.

stop ()

: Stop both motors.

boolean getValue ()

: Represents the speed of the motor as a floating point value that will either be -1 (full speed backward), 1 (full speed forward) or 0 (stopped).

boolean isActive ()

: Returns true if either motor is active.

PWM Motor

class com.diozero.api.motor.PwmMotor (forwardGpio, backwardGpio) source ¶

Represents a single motor controlled by two separate PWM signals. Extends MotorBase.

forwardGpio (int) - PWM-capable GPIO for forward / clockwise control.
backwardGpio (int) - PWM-capable GPIO for backward / anti-clockwise control.

PwmMotor (deviceFactory, forwardGpio, backwardGpio)

: Constructor.

deviceFactory (PwmOutputDeviceFactoryInterface) - Device factory to use for constructing the PWMOutputDevice instances.
forwardGpio (int) - PWM-capable GPIO for forward / clockwise control.
backwardGpio (int) - PWM-capable GPIO for backward / anti-clockwise control.

forward (speed)

: Stop the backward motor and set the forward motor speed.

speed (float) - value range 0..1.

backward (speed)

: Stop the forward motor and set the backward motor speed.

speed (float) - value range 0..1.

stop ()

: Stop both motors.

boolean getValue ()

: Represents the speed of the motor as a floating point value between -1 (full speed backward) and 1 (full speed forward).

boolean isActive ()

: Returns true if either motor is active.

TB6612FNGMotor

class com.diozero.devices.sandpit.TB6612FNGMotor (motorForwardControlPin, motorBackwardControlPin, motorPwmControl) source ¶

Represents a single motor controlled by one PWM signal and two separate forwards / backwards control digital signals. Extends MotorBase.

motorForwardControlPin (DigitalOutputDevice - Digital device controlling forward movement.
motorBackwardControlPin (DigitalOutputDevice - Digital device controlling backward movement.
motorPwmControl (PwmOutputDevice - PWM output device controlling relative motor speed.

DualMotor

class com.diozero.api.motor.DualMotor (leftMotor, rightMotor) source ¶

Convenience class for a robot with two Motors.

leftMotor (MotorInterface) - The left motor
rightMotor (MotorInterface) - The right motor

float[] getValues ()

: Get the directional values for both motors (-1 backwards .. 1 forwards).

setValues (leftValue, rightValue)

: Set the speed and direction for both let and right motors (clockwise / counter-clockwise).

leftValue (float) - Range -1 .. 1. Positive numbers for clockwise, Negative numbers for counter clockwise.
rightValue (float) - Range -1 .. 1. Positive numbers for anti-clockwise, Negative numbers for counter clockwise.

forward (speed)

: Set both motors forward at the specific speed. Range 0..1.

backward (speed)

: Set both motors backward at the specific speed. Range 0..1.

rotateLeft (speed)

: Turn the left motor backward and the right motor forward at the specific speed. Range 0..1.

rotateRight (speed)

: Turn the left motor forward and the right motor backward at the specific speed. Range 0..1.

forwardLeft (speed)

: Turn the right motor forward at the specified speed, stop the left motor. Range 0..1.

forwardRight (speed)

: Turn the left motor forward at the specified speed, stop the right motor. Range 0..1.

backwardLeft (speed)

: Turn the right motor backward at the specified speed, stop the left motor. Range 0..1.

backwardRight (speed)

: Turn the left motor backward at the specified speed, stop the right motor. Range 0..1.

reverse ()

: Reverse the direction of both motors.

circleLeft (speed, turnRate)

: Circle to the left.

speed (float) - Range 0..1.
turnRate (float) - Range 0..speed.

circleRight (speed, turnRate)

: Circle to the right.

speed (float) - Range 0..1.
turnRate (float) - Range 0..speed.

stop ()

: Stop both motors.

Servo

class com.diozero.devices.Servo (gpio, pwmFrequency, initialPulseWidthMs) source ¶

Represents a pulse-width controlled servo.

gpio (int) - GPIO
pwmFrequency (int) - Desired PWM frequency for the servo, typically 50Hz
initialPulseWidthMs (float) - Starting pulse width (in milliseconds). Range is 0.5ms - 2.6ms

getPulseWidthMs ()

: Get the current pulse width value (milliseconds)

float getPulseWidthMs (float pulseWidthMs)

: Set the pulse width value (milliseconds)

pulseWidthMs - New pulse width value (milliseconds)

Common Motor Controllers

CamJamKitDualMotor

class com.diozero.devices.CamJamKitDualMotor source ¶: Extends DualMotor. Convenience class for interfacing with the CamJam EduKit #3 Motor Controller Board with pre-configured GPIOs (left -> 9 and 10, right -> 7 and 8).

RyanteckDualMotor

class com.diozero.devices.RyanteckDualMotor source ¶: Extends DualMotor. Convenience class for interfacing with the Ryanteck RPi Motor Controller Board with pre-configured GPIOs (left -> 17 and 18, right -> 22 and 23).

TB6612FNGDualMotorDriver

class com.diozero.devices.sandpit.TB6612FNGDualMotorDriver source ¶: Extends DualMotor. Convenience class for interfacing with dual H-bridge motor drivers such as the Toshiba TB6612FNG Dual Motor Driver as used in the Pololu Dual Motor Driver Carrier.