Linux Format - UK (2020-03)

42 LXF260 March 2020 http://www.linuxformat.com

Raspberry Pi projects

ere we have two simple projects. The first tests

that we can wire up a simple circuit, while the

second project enables our Arduino to emulate

a USB keyboard, which we will then use to quickly

change the screen when our boss walks in. There are

two ways to code your Arduino: via an online editor, or

via the traditional Arduino IDE (integrated development

environment).

Head in the clouds

Plug in your Arduino Nano 33 IoT, then in a browser visit

https://create.arduino.cc and create a new account.

Follow the instructions, and when prompted download

and install the Arduino Create app. The app will detect

your Nano 33 IoT board and make it available to the

Arduino IoT Cloud. You will be asked to set up the crypto

chip on the Nano 33 IoT. This is essential for a secure

connection to the Arduino IoT Cloud. If you are using

another Arduino board, the installer will skip this section.

Down on the ground

If you wish to use the Arduino IDE, head over to https://

http://www.arduino.cc/en/Main/Software and download the

IDE for your system. Then follow the online instructions

to install the IDE to your desktop. One issue you will face

is that your user is not in the correct group to send data

to the Arduino. So to add your user to the group, open a

terminal and type the following (remember to change

<username> to your user name):

$ sudo usermod -a -G dialout <username>

Then reboot your computer before proceeding.

In the tutorial we use the Arduino IoT Cloud, but the

code is transferable between the two editors.

Project 1: Hello World

The most basic project we can create is to flash an LED.

But why do we do that? Firstly it confirms that we can

send data to the board, and secondly it confirms that

our electronic components work.

Get started with Ardiuino

We introduce a couple of easy projects to show you the

bread(boards) and butter of being an Arduino maker.

Hardware setup

The circuit for the project involves an LED, breadboard,

330 Ohm resistor and two male to male jumper wires.

The LED is placed into a breadboard, and the resistor is

connected to the short leg (the cathode, –, GND leg)

and to the GND pin of the Arduino via a jumper wire. The

long leg of the LED (Anode, +) is connected to pin 2 of

the Arduino via a jumper wire

Coding the project

In the Arduino IoT Cloud, click on Arduino Web Editor

and then connect the Arduino to your computer. Create

a new sketch in the Sketchbook. The first step is to

create a function that will tell the Arduino that we wish

to use pin 2 as an output to send current to the

connected LED.

void setup() {

pinMode(2, OUTPUT);

}

Our loop will run the code forever, and inside the main

loop is a for loop, a loop that will iterate (go round) three

times and quickly flash our LED before pausing.

void loop() {

for (int i = 0; i <= 3; i++) {

To light up the LED we need to use digitalWrite and

then pass the pin number and the state of the pin. In

this case we set pin 2 to HIGH, which will cause the

LED to light up. After a short, 100ms delay, we then

turn on the LED using LOW. Another delay occurs

before the for loop goes back to the start again. Once

the for loop has run three times, it will end and break

out. A final delay of 1 second (1000ms) will then cause

the LED to be off, and it will create a long pause in the

flashing sequence.

digitalWrite(2, HIGH);

delay(100);

digitalWrite(2, LOW);

H

The Arduino IDE

uses a tick to verify

that the code is

correct. An icon

with an arrow

pointing right

flashes the code to

the board.

Your first project should always be simple, as it is a test to ensure that

our code and hardware are working correctly.

An Arduino

Nano 33 IoT or

Leonardo

A breadboard

2x M2M

jumper wires

Project 1

An LED

330 Ohm

resistor

(Orange-

Orange-Brown-

Gold)

Project 2

Push button

/ momentary

switch

Code: https://

github.com/

lesp/LXF260-

Arduino/

archive/

master.zip

YOU NEED

42 LXF260March 2020 3332March 0Sens2i0e

Raspberry Pi projects

erewehavetwosimpleprojects.Thefirsttests

thatwecanwireupasimplecircuit,whilethe

secondprojectenablesourArduinotoemulate

aUSBkeyboard,whichwewillthenusetoquickly

changethescreenwhenourbosswalksin.Thereare

twowaystocodeyourArduino:viaanonlineeditor,or

viathetraditionalArduinoIDE(integrateddevelopment

environment).

Headintheclouds

PluginyourArduinoNano 33 IoT,theninabrowservisit

https://create.arduino.ccandcreateanewaccount.

Followtheinstructions,andwhenprompteddownload

andinstalltheArduinoCreateapp.Theappwilldetect

yourNano 33 IoTboardandmakeitavailabletothe

ArduinoIoTCloud.Youwillbeaskedtosetupthecrypto

chipontheNano 33 IoT.Thisisessentialforasecure

connectiontotheArduinoIoTCloud.Ifyouareusing

anotherArduinoboard,theinstallerwillskipthissection.

Downontheground

IfyouwishtousetheArduinoIDE,headovertohttps://

http://www.arduino.cc/en/Main/Softwareanddownloadthe

IDEforyoursystem.Thenfollowtheonlineinstructions

toinstalltheIDEtoyourdesktop.Oneissueyouwillface

isthatyouruserisnotinthecorrectgrouptosenddata

totheArduino.Sotoaddyourusertothegroup,opena

terminalandtypethefollowing(remembertochange

<username>toyourusername):

$ sudousermod-a-Gdialout<username>

Thenrebootyourcomputerbeforeproceeding.

InthetutorialweusetheArduinoIoTCloud,butthe

codeistransferablebetweenthetwoeditors.

Project1: HelloWorld

Themost basic project we can create is to flash an LED.

Butwhydo we do that? Firstly it confirms that we can

senddata to the board, and secondly it confirms that

ourelectronic components work.

Get started with Ardiuino

We introduce a couple of easy projects to show you the

bread(boards) and butter of being an Arduino maker.

Hardwaresetup

The circuit for the project involves an LED, breadboard,

330 Ohm resistor and two male to male jumper wires.

The LED is placed into a breadboard, and the resistor is

connected to the short leg (the cathode, –, GND leg)

and to the GND pin of the Arduino via a jumper wire. The

long leg of the LED (Anode, +) is connected to pin 2 of

theArduinoviaajumperwire

Coding the project

In the Arduino IoT Cloud, click on Arduino Web Editor

and then connect the Arduino to your computer. Create

a new sketch in the Sketchbook. The first step is to

create a function that will tell the Arduino that we wish

to use pin 2 as an output to send current to the

connected LED.

void setup() {

pinMode(2, OUTPUT);

}

Our loop will run the code forever, and inside the main

loop is a for loop, a loop that will iterate (go round) three

times and quickly flash our LED before pausing.

void loop() {

for (int i = 0; i <= 3; i++) {

To light up the LED we need to use digitalWrite and

then pass the pin number and the state of the pin. In

this case we set pin 2 to HIGH, which will cause the

LED to light up. After a short, 100ms delay, we then

turn on the LED using LOW. Another delay occurs

before the for loop goes back to the start again. Once

the for loop has run three times, it will end and break

out. A final delay of 1 second (1000ms) will then cause

the LED to be off, and it will create a long pause in the

flashing sequence.

digitalWrite(2, HIGH);

delay(100);

digitalWrite(2, LOW);

H

The Arduino IDE

uses a tick to verify

that the code is

correct. An icon

with an arrow

pointing right

flashes the code to

the board.

Your first project should always be simple, as it is a test to ensure that

our code and hardware are working correctly.

AnArduino

Nano 33 IoTor

Leonardo

Abreadboard

2x M2M

jumper wires

Project 1

An LED

330 Ohm

resistor

(Orange-

Orange-Brown-

Gold)

Project 2

Push button

/ momentary

switch

Code: https://

github.com/

lesp/LXF260-

Arduino/

archive/

master.zip

YOU NEED