AccelStepperAddon - MATLAB Interface for Arduino Stepper Motor Control

MATLAB add-on that allows to control stepper motors through an Arduino board by interfacing the powerful AccelStepper library. It is inspired by the DHT22 add-on provided by MATLAB and follows the MATLAB Arduino add-on library guide.

Confirmed to work in MATLAB 2023b on Arduino Pro Mini, Uno R3, and Due using the common 28BYJ-48 stepper motors with ULN2003A controllers.

How to install

• Install the MATLAB Support Package for Arduino.
• Copy the AccelStepper library files into a new folder AccelStepper created in your MATLAB Arduino library folder, typically located in C:\ProgramData\MATLAB\SupportPackages\R2023b\aIDE\libraries.
• Create a folder +arduinoioaddons in your working directory.
• Create a folder +AccelStepperAddon inside this folder.
• Paste the files of this project into it.
• Your folder structure should now look like this.

Usage examples

See Example.m for the complete code example.

Create the Arduino object using the AccelStepperAddon library:

a = arduino('COM4', 'Due', 'Libraries', ...
    {'AccelStepperAddon/AccelStepperAddon'}, 'Traceon', true)

Create a stepper object with pins D2-D5:

s1 = addon(a,'AccelStepperAddon/AccelStepperAddon', {'D2','D3','D4','D5'})

Set the maximum speed of the stepper:

s1.setMaxSpeed(400)

Get the maximum speed of the stepper:

s1.maxSpeed()

Set the acceleration of the stepper:

s1.setAcceleration(400)

Get the acceleration of the stepper:

s1.acceleration()

Enable the stepper to step when a step is due, implementing acceleration and deceleration to reach the target position:

s1.startrun()

Get the remaining steps:

s1.distanceToGo()

Move to absolute position 1000:

s1.moveTo(1000)

Move back 100 steps:

s1.move(-100)

Get the current target position:

s1.targetPosition()

Get the current position:

s1.currentPosition()

Set the current position to 0:

s1.setCurrentPosition(0)

Check if the stepper is stepping:

s1.isRunning()

Stop the stepper with deceleration:

s1.stop()

Disable the corresponding outputs of the stepper:

s1.disableOutputs()

Enable the corresponding outputs of the stepper:

s1.enableOutputs()

Create a second stepper:

s2 = addon(a,"AccelStepperAddon/AccelStepperAddon", 'DRIVER', {'D7', 'D8'})

Set the minimum pulse width allowed by the stepper driver:

s2.setMinPulseWidth(50)

Set the enable pin for the stepper driver (default ''):

s2.setEnablePin('D6')

Invert the enable pin:

s2.setPinsInverted(false, false, true)

Set the maximum speed of the stepper:

s2.setMaxSpeed(400)

This limits the value of setSpeed, but there is a quirk in the AccelStepper library: After decreasing the value of setMaxSpeed below the value of setSpeed, AccelStepper respects this updated limit only if the value of setSpeed is also changed; increasing the value of setMaxSpeed above the value of setSpeed, however, is respected even after calling setSpeed() with the current speed.

Set the speed for the constant speed movement:

s2.setSpeed(123.456)

Get the speed for the constant speed movement:

s2.speed()

Start movement with constant speed:

s2.startrunSpeed()

Stop movement immediately:

s2.stoprun()

Clean up (takes ~20 seconds):

clear a s1 s2

Notes

The following AccelStepper library functions are not implemented in this interface yet:

• runToPosition
• runSpeedToPosition
• runToNewPosition

Note that for the 28BYJ-48 stepper the middle two pins must be swapped physically (initialized with {'D2','D3','D4','D5'}) or in software (initialized with {'D2','D4','D3','D5'}).

The maximum number of steppers is currently hardcoded to MAX_NUMBER_STEPPERS = 4 in AccelStepperAddon.h and AccelStepperAddon.m to reduce the allocated memory. It can be changed before building and flashing the Arduino.

References

• The interfaced library: https://www.airspayce.com/mikem/arduino/AccelStepper
• Following the MATLAB Arduino add-on library guide: https://www.mathworks.com/help/supportpkg/arduinoio/custom-arduino-libraries.html
• Following the MATLAB example: https://www.mathworks.com/matlabcentral/fileexchange/72441-dht22-add-on-library-for-arduino
• Example of the add-on folder structure: https://www.mathworks.com/help/supportpkg/arduinoio/ug/create-custom-folder-structure.html