arduino matlab

5/28/2018 Arduino Matlab

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Learning Basic Mechatronics concepts

using the Arduino Board and MATLAB

rks,

Inc.

009T

heMathWo, ,

The MathWorks, 400 Continental Blvd, Suite 600-028,

El Segundo, CA, 90245

2. .


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A few challenges with Mechatronics projects

r u no ntro uct on ot vat on

Motor Control

Arduino target and Useful Links

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, , ,

Touch, Orientation, Motion/Speed, Environment, Optical,Chemical, Flow, Voltage/Current, sensor selection is

largely application related but also related to:

Number of sensors

Ranges

A/D conversion issues as Resolution and Sampling Rate

Signal Conditioning

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Development-Prototyping Environment

Low-Level Programming Language, Compiler/Assembler

Connection to computer (or LCD) for visualization

DAQ typically already there

Stand Alone Issues ower re uirements

Computer

onnec on o , , er a , re ess Programming-Analysis Environment

OS / Drivers (Real Time ?)

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Embedded / Small Form Factor Computer


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,

Relays

Motors

DC/Steppers/Servos

gna mp ca on

Power Suppliers, Batteries

Forward/Reverse, H-Bridges

Displays

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Cost

Eas of Use

Flexibility

Non trivial process even for simple projects

Some challenges are inherent to the multidisciplinary

u u uwith them (e.g. sensors, actuators, power, design)

Some are not e. . debu in C code drivers issues

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hardware limitations, unreadable manuals, high costs)


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Motor Control


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Arduino is an open-source microcontroller board, with anassociated development environment.

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The schematics and the software are released under theCreative Commons License

Manufacturing and Distributing an official Arduino product

to be contacted) to make sure that:

Things work properly.

e pro uc s n o e overa pro ec . It is manufactured under reasonably fair labor conditions.

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Some form of contribution might be traded in this case


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ATme a328 microcontroller

16 MHz, 32 KB FLASH, 2KB SRAM, 1K EEPROM 19 DIO pins (6 can be 8-bits 500Hz PWM outputs)

6 analog inputs (10 bits over 0-5V range, 15kSPS)

5V operating voltage, 40 mA DC Current per IO Pin

I2C (TWI) fully supported and SPI partially supported

USB connection (FTDI chip converts USB to Serial)

Power jack and optional 9V power supplier

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They extend its functionality to control different devices,acquire data, and so on

Examples: o or epper ervo e s o or on ro

Multichannel Analog and Digital IO Shields

Prototyping Shields

Ethernet and Wireless communication Shields Wave Shields (Audio)

GPS Lo in and Accelerometer Shields

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Relay Control Shields


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Motor Control


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Projects requiring Analog and Digital IO

Mechatronics Projects using Servo, DC or Stepper Motors

Projects with volume/size and/or budget constraints

ro ec s requ r ng some amoun o ex y anadaptability (i.e. changing code and functions on the fly)

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Basically any Mechatronics project requiring sensing andacting, provided that computational requirements are not

too high (e.g. cant do image processing with it)

Projects

There is a very large community of people using it for all

kind of projects, and a very lively forum where it is

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Arduino IO Package:Used to perform analog and digital input and output as

Arduino Target:

Used to compile and download Simulink code directly to

e r u no oar

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.

MATLAB is more interactive, results from Digital/AnalogI/O instructions can be seen immediately without needing

.

It is a good idea even just for algorithm prototyping

MATLAB code is generally more compact and easier to

understand than C (higher-abstraction data types,

, ,of code) which means:

a MATLAB scales better with ro ect com lexit

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b) People get the job done faster in MATLAB


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.

For wider-breadth ro ects that mi ht include data

analysis, signal processing, calculations, simulation,statistics, control design ) MATLAB is better suited

Engineering Departments typically need to introduce

MATLAB durin the first ears so this acka e will allow

professors to keep the same environment and students to

practice more MATLAB

People might already be more familiar with MATLAB than

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Motor Control


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USE:

ConnectAssign Pin Mode

Digital Output

Analog InputDisconnect

Un lu

na og u pu

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Use the command a=ar dui no( por t ) , with the rightCOM port as a string input argument, to connect MATLAB

workspace:

>> a=ar dui no( COM5 ) ;

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Use the command a. pi nMode( pi n, st r )to get or set the mode of a specified pin:

Examples:

>> a. pi nMode( 11, ' out put ' )>> a. pi nMode( 10, ' i nput ' )>> val =a. pi nMode( 10)

.

>> a. pi nMode;

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Use the command a. di gi t al Read( pi n) to read thedigital status of a pin:

Examples:

>> val =a. di gi t al Read( 4)

This returns the value (0 or 1) of the digital pin number 4

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>> a. di gi t al Read( 4)

ans =

Command

executed while

button is released

0

>> a. di gi t al Read ( 4) Command

executed while

MATLABCommand

Window

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ans =

1

u on s presse


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Use the command a. di gi t al Wr i t e( pi n, val )with the pin as first argument and the value (0 or 1) as

a. di gi t al Wr i t e( 13, 1) ; % set s pi n #13 hi gha. di gi t al Wr i t e( 13, 0) ; % set s pi n #13 l ow

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>> a. di gi t al Wr i t e( 9, 1)

Command

Window

a. g a r e ,

Led OnLed Off

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Use the command val =a. anal ogRead( pi n)with the pin as an integer argument:

Example:

val =a. anal o Read 0 % r eads anal o i n # 0

The returned argument ranges from 0 to 1023

Note that 6 analog input pins (0 to 5) coincide with the

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g a p ns o an are oca e on e o om r g

corner of the board


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>> a. anal ogRead( 3)MATLAB

ans =

285

Window

>> a. anal ogRead( 3)

ans =

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Use the command a. anal ogWr i t e( pi n, val ) with thepin as first argument and the value (0 to 255) as second

a. anal ogWr i t e( 11, 90) ; % set s pi n #11 t o 90a. anal ogWr i t e( 3, 10) ; % set s pi n #3 t o 10

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>> a. anal ogWr i t e( 9, 10)

Command

Window

a. ana og r e ,

Led On (20%)Led On (4%)

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Use the command del et e( a) to disconnect the

MATLAB session from the Arduino board:

the IDE environment

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This challenge is described in the last part of the LadyadaArduino tutorial, http://www.ladyada.net/learn/arduino/ and

(user switches mode by pushing a button):

1. All LEDs Off

2. All LEDs On

. s n ng s mu aneous y w var a e requencyregulated by a potentiometer

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.

variable speed regulated by a potentiometer


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INPUTSOUTPUTS

MATLAB

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USER


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% initialize pins

disp('Initializing Pins ...');

% get previous state

prev=a.digitalRead(bPin);

% sets digital input pins

a.pinMode(2, 'INPUT');



% start loop

disp('Starting main loop, push button to change state ...');

% loop for 1 minute



% sets digital and analog (pwm) output pins

a.pinMode(5, 'OUTPUT'); % pwm available here' '

c

while toc/60 < 1

% read analog input

ain=a.analogRead(aPin);v=100*ain/1024. ,

a.pinMode(9, 'OUTPUT'); % pwm available here

a.pinMode(10,'OUTPUT'); % pwm available here

a.pinMode(11,'OUTPUT'); % pwm available here

a.pinMode(12,'OUTPUT');

a.pinMode(13,'OUTPUT');

% read current button value

% note that button has to be kept pressed a few seconds to make sure

% the program reaches this point and changes the current button value

curr=a.digitalRead(bPin);

% button pin and analog pin

bPin=2;aPin=2;

% initialize state

% button is being released, change state

% delay corresponds to the "on" time of each led in state 3 (wave)

if (curr==1 && prev==0),

state=mod(state+1,4);

' ' ' '

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state= ; ,

end


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% toggle state all on or off% wave

if (state==3), ,

for i=9:13,

a.digitalWrite(i,state);

end

end

or = : ,

a.digitalWrite(9+mod(i,5),0);

a.digitalWrite(9+mod(i+1,5),1);

pause(v/200);

end

a.digitalWrite(13,0);

% blink all leds with variable delay

if (state==2),

forj=0:1,

% analog output pins

% update state

prev=curr;

or = : ,

a.analogWrite(i,20*(i-8)*j);

end

% digital output only pins

for i=12:13, % turn everything off

fori=9:13, a.digitalWrite(i,0); end. ,

endpause((15*v*(1-j)+4*v*j)/1000);

end

end

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The schematics was implemented using the prototyping

shield:

This shield allows for an easy prototyping of projects

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based on the Arduino board


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Pot toButton tochange

on/off

LEDs

delay

Boardunderneath

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Motor Control


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Servo Ports

# 1 & 2

Motor Ports

# 3 & 4

Stepper Port #2

Motor Ports

# 1 & 2

Arduino

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Board

underneath

External

Power

Connector

Jumper on == same

power source for both

Arduino and motor shield


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2 connections for 5V 'hobb ' servos connected to the

Arduino's high-resolution dedicated timer

Up to 4 bi-directional DC motors with individual 8-bit

speed selection

Up to 2 stepper motors (unipolar or bipolar) with single

coil, double coil, interleaved or micro-stepping.

4 H-Bridges: L293D chipset provides 0.6A per bridge

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. pea w erma s u own pro ec on, . o


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Plug Board USE:

Connect

Plug Servo Servo Attach

Servo Write

Servo Read

Unplug Servo

Disconnect

ervo e ac np ug oar

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Use the command val =a. ser voSt at us( num) to get

the status of a servo, which can be either:

a ac e rea y or rea or wr e

detached (pin 9 or 10 can be otherwise used)

Examples:val =a. ser voSt at us( 1) ;

a. ser voSt at us( 2) ;a. ser voSt at us;

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Use the command a. ser voAt t ach( num) to attach a

servo to the corresponding pwm pin (servo #1 uses pin

, .

a. ser voAt t ach( 1) ; % at t ach ser vo #1a. ser voAt t ach( 2) ; % at t ach ser vo #2

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Use the command val =a. ser voRead( num) to read the

angle from a servo. The argument is the number of the

.

The returned value is the angle in degrees,

typically from 0 to 180.

Examples:val =a. ser voRead( 1) ; % r ead angl e ser vo #1val =a. ser voRead 2 % r ead an l e ser vo #2

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Use the command a. ser voWr i t e( num, val ) to rotate

a servo of a given angle.

e rs argumen s e num er o e servo, e secon

is the angle.

Examples:

a. ser voWr i t e( 1, 45) ; % r ot at es 45 ser vo #1

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Use the command a. ser voDet ach( num) to detach a

servo from the corresponding pwm pin.

Examples:

a. ser voDet ach 1 % det ach ser vo #1a. ser voDet ach( 2) ; % det ach ser vo #2

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>> a. ser voAt t ach( 2)MATLAB

Command

External Power:6V Lantern Battery

Power Jumperon (suggested)

. ,

>> a. ser voWr i t e(2, 180)

>> a. ser voRead( 2)

n ow:

ans =

180Servo #2

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Plug Board USE:

Connect

Wire Motor

e pee

Run (or Step)

Unwire

Disconnect

np ug

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Use the command val =a. mot or S eed( num, val ) ; to

get or set the speed of a DC motor.

The first argument, num, is the number of the motor (1 to

e secon argumen s e spee o

a. mot or Speed( 4, 200) ;val =a. mot or Speed( 1) ;a. mo or pee ;a. mot or Speed;

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Note: nothing moves unless we issue a run command


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. ,

motor.

The first argument, num, is the number of the motor (1 to 4)

the second argument is a string that can be either

forward, backward, release

Examples:a. mot or Run( 1, ' f or war d' ) ;

a. mot or Run( 3, ' backwar d' ) ;a. mot or Run( 1, ' r el ease' ) ;

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a. mo or pee ,

>> a. mot or Run( 3, f orward )

Command

Window:

(running)

Motor #3

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Use the command val =a. st e er S eed( num, val ) ;

to get or set the speed of a stepper motor.

The first argument, num, is the number of the motor (1 to

e secon argumen s e spee n o

a. st epper Speed( 2, 50)val =a. st epper Speed( 1) ;a. s epper pee ;a. st epper Speed;

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Again, nothing moves unless we issue a step command ...


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a. st epper St ep( num, st r , st y, st eps) ; to advance a

stepper motor of a certain number of steps.

ere nums t e num er o t e stepper or , st r canbe either forward, backward, release, st y is the style

of motion and can be sin le double interleavemicrostep, st eps is the number of steps (0 to 255)

Examples:a. st epper St ep( 1, ' f or war d , i nt er l eave , 50) ;a. st e er St e ( 1, backwar d , doubl e , 200) ;

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a. st epper St ep( 1, ' r el ease' ) ;


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a. s epper pee ,

>> a. st epper St ep( 1, ' backwar d' , ' mi cr ost ep' , 100)

Command

Window:

Arduino Target, Links, Conclusion

Stepper #1 Coil #1

Coil #2

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Motor Control


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Arduino IO:

Used to perform analog and digital input and output from

Used to compile and download Simulink code directly to

the Arduino board

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An extensive list of sites where you can buy

an Arduino is here:. .

http://www.adafruit.com/

provides a starter pack that includes pretty much

.

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RC Servos from Pololu:

http://www.pololu.com/catalog/category/23

DC Motors from Pololu:

http://www.pololu.com/catalog/category/51

Jameco for Stepper Motors and pretty much everything:

http://www.jameco.com/

List of Hobbyist and Surplus Stores:

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p: www. a ya a.ne rary procure o y s . m


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Official Arduino web site: http://arduino.cc/en/

Knowledge base: http://www.freeduino.org/

Official Getting Started guide:

http://arduino.cc/en/Guide/HomePage

http://www.ladyada.net/learn/arduino/

MATLAB ArduinoIO package, send me an email here:[email protected]

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mu n r u no arge : searc or n en ra

(or google for Arduino Target)


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Arduino is an inexpensive open-source microcontroller

board, well suited for a wide range of projects

Arduino + ArduinoIO package + MATLAB =

the MATLAB command line

Arduino + Motor Shield + ArduinoIO package + MATLAB= inexpensive and interactive Motor Control from the

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arduino matlab

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