Arduino Online Tutorials - EP Software

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Arduino Basics | TUTORIAL by EP Software | © 2019 | of 52

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Content.

1 Introduction ........................................................................................................ 3

2 Set up the software and open a new sketch ......................................................... 4

3 Let the Arduino speak to your computer .............................................................. 6

4 Build your first circuit .......................................................................................... 8

5 LED on! – Variable types .................................................................................... 10

6 LED on-off-loop ................................................................................................. 12

7 if-then-else ........................................................................................................ 13

8 Button circuit ..................................................................................................... 15

9 Press button -> LED on ...................................................................................... 16

10 LED switch ....................................................................................................... 18

11 switch-case function ........................................................................................ 19

12 First own function ........................................................................................... 20

13 Traffic light circuit ........................................................................................... 22

14 Traffic light ..................................................................................................... 23

15 Dimmer ........................................................................................................... 25

16 For-loop .......................................................................................................... 26

17 LED increase/decrease ..................................................................................... 27

18 Traffic light with dimmer function ................................................................... 28

19 RGB circuit ....................................................................................................... 30

20 LED back and forth .......................................................................................... 31

21 While-loop ....................................................................................................... 35

22 Chaser with while-loop .................................................................................... 36

23 Chaser with while-loop and dimmer ................................................................. 38

24 Police flashlight ............................................................................................... 41

Final codes ............................................................................................................ 42

“Let your Arduino speak to your computer” ........................................................ 43

“LED on! – Variable types” ................................................................................... 43

“LED on-off-loop” ................................................................................................ 44

“Press button -> LED on” ..................................................................................... 44

“LED switch” ....................................................................................................... 45

“switch-case function” ........................................................................................ 45

“Traffic light” ...................................................................................................... 46

“Dimmer” ........................................................................................................... 46

“LED increase/decrease” ..................................................................................... 47

“Traffic light with dimmer” ................................................................................. 47

“LED back and forth” .......................................................................................... 48

“Chaser with while-loop” ..................................................................................... 49

“Chaser with while-loop and dimmer” ................................................................. 50

“Police flashlight” ............................................................................................... 51

References ............................................................................................................ 52

Images: .............................................................................................................. 52

Code: ................................................................................................................. 52

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1 Introduction

Welcome to the EP Software Arduino Basics Online Tutorial!

In this tutorial, you will learn the basics for programming an Arduino and simple

programming skills useful for all programming languages such as C, Java and more.

In the coming twenty-four-step tutorial, we will start with easy programming steps

and in the end, you will have made some small but wonderful Arduino projects. The

skills you will learn are good for continuing furthermore.

For a start, you need some Arduino gadgets. You will find the following gadgets on

Amazon or other resellers:

- Red-, Blue-, Green-LED

- Three 220-Ohm Resistors

- One 10k-Ohm Resistor

- Button

- Cables

- Arduino (or other) UNO

- Breadboard

You can buy every single item or all together in a bundle. For example, “FREENOVE

Super Arduino Starter Kit” (link) includes all needed items, only for 19,95 € on

Amazon.

Also, for programming, you will need the “Arduino IDE” software. Download the

“Arduino IDE” here. Do not worry this software is free!

In this tutorial we use the following icons to highlight important points:

Grey frame

The grey frame contains basic theory

that is always of great importance to a

programmer. Many of the info symbols

are also found here

The info symbol declares important

theory for this tutorial.

The thinking man always shows where a

task is waiting for you

Please give us a feedback on our website about your experience with this Arduino

Online Tutorial. Do you think we should publish more tutorials for an Arduino? Tell

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2 Set up the software and open a new sketch

First of all, the software setup:

1. Connect your Arduino with your Computer

2. Start “Arduino IDE”

3. Go to “Tools” -> “Board” -> and select your Arduino Board, in our example

“Arduino/Genuino UNO”

4. Go to “Tools” -> “Port” -> and select the Port, for example “COM6

(Arduino/Genuino UNO)”

5. Now the Arduino IDE knows how to find your Arduino

Now we turn to the Arduino IDE itself! Open a new sketch (“File” -> “New”).

What do we see?

In the new sketch are already added two functions. Please never delete these two

functions! Why do we need these functions?

The setup function

This function is called, whenever you start your Arduino. This means you upload a

new sketch to the Arduino board, or you will switch it simply on again by plugging it

to the USB Port or another power source.

We use the function for initialising new variables or other stuff.

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The loop function

This function will repeat all code as fast as possible, which is in this function. It is

working like a repeater. We will use this function for running simply everything.

In sum, these both functions are starting and running our code and Arduino.

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3 Let the Arduino speak to your computer

Start the Arduino IDE, open a new sketch and connect the Arduino to your

computer.

We will use now the “Serial Monitor”. The serial monitor will show the answers from

our Arduino on our computer. We will use it to check, if our programme is doing

right, later on. The Arduino needs to know how to reach the monitor compared to

our daily lives, where we need to know what the recipient's address is.

We will give the Arduino this information in the setup function, which you learned

about in the last chapter.

First code! We write in the setup function following code:

This information says: Start the serial monitor with the address “9600”.

After initialising the serial monitor, we will send a message that our programme has

started. We continue in the setup function:

“println()” means we are printing the following text “---Programme started---“ in a

new line. If you want to print several information in one row, you can write

“.print(#text#);”.

You may have recognized that after every statement we are writing a semicolon (“;”).

The software needs this symbol to know, where a statement is finished. This is

equal to a point at the end of a sentence.

Now it is time to start our programme. First, we are starting the serial monitor. Go

to “Tools” -> “Serial monitor”. A new window will appear. Check if in the low right

corner, in the drop-down menu, “9600 baud” is selected.

Now we are uploading the code to the Arduino. Click on the right arrow button ( )

in the left upper corner. The software will now check our code, if any errors have

been made, afterwards the code will be uploaded. Our Arduino will show us, with a

small light show, that the code has been uploaded.

If you have problems with coding, you will find at the end of this document all

solutions for any chapter/step in this tutorial, or click on the link at the end of each

chapter/step.

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If the code is compiled and executed, we will find our coded message in the serial

monitor:

Click here for final code

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4 Build your first circuit

We will build in this chapter our first Arduino circuit, which we will use afterwards…

Take your breadboard, 220-Ohm resistor two cables and the red LED. Follow the

instructions below:

Each slot in the breadboard is for one

pin of a cable, LED or resistor. In every

row the columns (Terminal Strips) a, b,

c, d, e and f, g, h, i, j are connected, so

if you apply voltage to one of these

slots, all other four pins will have this

voltage. The Divider splits the Terminal

Strips from each other. Otherwise are

the + and – column (Power rails) not

connected horizontal (row), but vertical

(column). If you will apply voltage to

one of their slots, all pins in the column

will have this voltage.

We will use the + and – column for

feeding all components with voltage.

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Now it is time to build the first circuit, as shown in the image above. The black lines

are symbolizing cables. Our red LED has two pins, a long and a short one. Please

place/connect the long pin in the same row as the 220-Ohm resistor. Connect the

other end of the 220-Ohm resistor to digital port 2. Connect the other pin of our red

LED to the Ground (GND) of the Arduino, as shown in the image above via the power

rails. We will need more connections to the ground (GND) later on.

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5 LED on! – Variable types

As we finished to build the small circuit, we program the corresponding programme.

We learnt before, that our Arduino does not know much about its ports (pins). So,

we have to teach it, which port is connected to what. First, we setup all information

about the port. If the port is sending or receiving data. We use following code:

pinMode(pin number, type (OUTPUT/INPUT);

Open a new sketch. Add this line of code to the setup function of the new sketch.

Now our Arduino knows that pin (port) number “redLED” is a pin where a current/

message leaves our Arduino. If the pin takes the role as a receiver, we will write

“INPUT” instead of “OUTPUT”. If we would compile the code with just this line of

code, our Arduino software will spit an error. Because the Arduino does not know

what “redLED” is. We must define the variable “redLED” before starting. The variable

“redLED” is an integer (number). We will write following code before our setup

function:

As you can see to define a variable we start with the type of variable (integer, string,

long, …), afterwards we write the name of our variable. If we want to give our

variable right away a specific value, you define it afterwards. Finish the code line

with the semicolon (“;”). The following chart shows you all kinds of short cuts for

variable types:

Type Example Variable short cut

Integer 10000 int

String “Hello” String

Long (integers

higher/lower than +/-

32.767)

350.000 long

Float 1,2 float

Char (similar to String) “Hello” char

Array (of a variable type

before) “Hello”, “Bye” array

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The code so far:

The last missing bit of our code for turning the LED on and off is coming right now.

After setting the pin mode, we want to turn on the LED. Because we are using the

digital Pin number two, we will write following code in the setup function:

digitalWrite(number of pin, state: HIGH/LOW);

The digitalWrite() function needs two information. The pin number (redLED) and

which state should be sent. There are two states: “HIGH” (maximum current) and

“LOW” (no current), or in another way: power (in our case LED) on/off.


After adding the last line of code, we can compile and run our new code. Do not

forget to plug your Arduino to your computer. If you have any problems with

uploading the code to your Arduino, check if Port and Board are set right in the

“Tools” menu.

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6 LED on-off-loop

In the last chapter, we learnt how to turn our LED on. Now we are programming a

small chaser. As the chapters heading says, we are using now the loop function.

Open the sketch from last chapter. Delete line two in the setup function

(digitalWrite(redLED,HIGH);).

Before we will continue, we need to learn about the delay function. This function

stops for given milliseconds all threads (processes) of the Arduino. We use this

function only, if we do not need other essential threads keep running at the same

time!

delay(milliseconds);

We add now following lines to our loop function:

The code above does turn on the LED, holds this state for half a second and then

turn the LED off again. The whole process starts again after another delay of half a

second. You can change the delay and add more states if you want!

Compile and run...


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7 if-then-else

More theory! The if-then-else condition is the most important condition we use.

What should happen, if a state is true or false and if not, what is to do instead? Basic

but important for every programme, because a computer can not decide on his own.

We have to set rules, just as a country needs rules to proceed in any case.

The basic of the if-then-else condition (always the same in any programming

language):

If (condition){

//several instructions that are executed if the condition evaluates to

True

}

After “if”, we have to establish a condition, which the Arduino/computer can check,

when the algorithm is running. After the curly brackets, you can write your code for

what should happen, if the condition evaluates to True.

If the condition evaluates to False, the algorithm will do nothing. If we want the

computer to do something else, then we have to add the else-algorithm:

If (condition){

//several instructions that are executed if the condition evaluates to

True

}else{

// several instructions that are executed

if the condition evaluates to False

}

For example, we can check now if a value is lower or equal/higher then 100:

This example will return “Lower”, because 50 is minor 100.

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It is even possible to interconnect more than one if-then-else condition:

You have many possibilities with the if-then-else condition. You will always use it

once in a programme!

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8 Button circuit

The next circuit for our breadboard is coming…

In this chapter, we will build the button circuit. A button is an important component

for handling interactions between the Arduino and yourself. You press the button

and something starts, for example, the pedestrian traffic light goes green.

We need the 10k-Ohm resistor, the button and five cables:

Build the circuit like the plane above shows. We will use it in the next chapters…

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9 Press button -> LED on

We have to modify our circuit before programming. Because we want to programme,

that if you press the button, our red LED will glow.

We need the 220-Ohm resistor, red LED and to more cables, for adding the same

circuit from chapter four:

After you have modified the circuit, we start with programming…

First, we have to initialise the button pin and give the Arduino all information

needed:

We remember: LED – Output, Button – Input, important for setting the pinMode().

In addition, we initialise the serial monitor, to check the button state later.

We will add now to the loop function the digitalRead() function. The

digitalRead() function will give us the input-data back, for reading the button

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state. We also need a variable to save the receiving button state. Because the button

just can have to button states (pressed/not pressed), we can use a Boolean variable.

A Boolean can only have to states true or false, just as the button has.

We add the following line above the setup function:

And following line to the loop function:

Now, we get the button state. We need to use this information! We learnt already

something about the if-then-else condition. We will use this condition now to set

what our Arduino should do if the button is pressed. Good to now: if the button is

pressed the digitalRead() function sends us “true” back.

We add now our first if-then-else condition. Our goal now is to send the current

button state back to the computer (serial monitor):

Because we do not like to overcrowd the serial monitor, we add a delay about one

second.

Give the code a go and check if the button works, by pressing the button. The Serial

monitor should reflect your action, by printing “Button pressed”.

Now a step further…

We want to light up the red LED if the button is pressed.

To do that, we exchange the serial.println() functions with the digitalWrite()

function:

You can remove the delay now, if you want.


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10 LED switch

Last chapter, we have created an algorithm to switch on our red LED as long we

pressed the button. This chapter, we will modify this algorithm to turn our button to

a real light switch.

The only thing what will change is that we have to save in which state our LED is

(on/off) and the buttonState condition is no longer responsible for turning the LED

on or off.

First, we add a new variable. The new variable is, as the buttonState variable, a

Boolean. Please add following line to the variable setup in the beginning of the

programme:

We will change the buttonState condition so that if the button is pressed the light

state will be changed:

The last bit, which is missing, is a condition, which turns on or off the red LED. Try

it yourself first. The solution is on the next page…

Notice: Please add a delay of 200 milliseconds to the loop function to have a better

handling!

Click here for final code.

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11 switch-case function

The switch-case function makes it much easy and tidier for us to check, if some

value is called and to process it.

The switch-case function has an easy structure:

switch(variable) {

case value: //something happens

break;

case other value: //something different happens

break;

}

The switch()-statement is the beginning and calls the variable whose value should be

compared with various values. Each comparison starts with “case”. Afterwards you

write the value (only integer or string/char is allowed to use) and then a colon. Now

you can add all statements, which should be done if the variable is equal to the

value. If you end the statements for one case, you finish it with “break;” which stops

the switch function.

An example (the only different, compared to last chapter´s code, is that we changed

the lightState variable type from Boolean to Integer, so true = 1 and false = 0):


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12 First own function

We want to teach you how to

programme an Arduino and we

want to show you basics

programming skills, then we do

not come around to show you

the best way of keeping your

programme tidy!

A good programmer does not

write all statements (functions)

down in a long list. He

outsources all statements

(function) separately in their

own functions. For example,

we outsource all conditions

from our loop function, from

last chapter´s code (Screenshot

on the left).

Structure of a function without

any return value:

void [Name]([Variable type]

[Name of the variable]){

//statements

}

Structure of a function with a

return value:

int [Name]([Variable type]

[Name of the variable]){

int value = 0;

//statements

return value;

}

The declaration of a new function starts with "void", if the function should return a

value, write down the type of a variable. This is followed by the name of the

function, such as "LightOnOff". Afterwards between the brackets you can define

variables which, when executed, can be passed to the function and used in the

function. If you want to return a value, terminate the function with return [value /

variable]. This statement terminates the function, all lines after that are not

executed!

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In the future, we will write all algorithm in separate functions, which will be

executed from other functions. To execute a function, you will write the Name, such

as “LightOnOff” and behind it brackets. If the function needs parameters given

along, add them to the brackets, for example: LightOnOff(lightState).

Update your code as shown on the page before.

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13 Traffic light circuit

We will start with a new project. Our new project is to program two LEDs

(red/green), which should act like a pedestrian traffic light. If you now think, that we

already had this project quiet similar before, do not worry, we will add some extra

functions!

We will start with the circuit for this project:

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14 Traffic light

First, try to programme a traffic light with the knowledge obtained so far, which at

the push of a button changes from red to green and the other way around. Do not

continue to the next page, if you want to try it!

A hint for all who like to try, but do not know further:

We need if-then-else conditions, digitalWrite() and digitalRead(). In the best

way, you build it up with self-made functions.

You have no clue? Try to use the if-then-else condition to check the button and

traffic light (if it is red or green) state.

If you have succeeded, tried it, or just skipped the task, we are now programming

the traffic light together…

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First, we set up the variables:

The “TrafficLightState” variable will save the current traffic light state

(red/green).

Afterwards, we initialise all components as learnt:

Now comes real programming. We need

to receive the button state and afterwards

use this information to set the current

state of our traffic light.

The checkButtonState() function

analysis the buttonstate variable and

changes the TrafficLightState to zero

for red or one for red. The

turnonlights() function use the

TrafficLightState variable to switch

the right LED on each run of the loop

function. If you want, you can modify

your code that the LEDs switch only, if the

button is really pressed. We will dissolve

it tomorrow!


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15 Dimmer

We will change the circuit a little bit, because not all pins are capable of dimming

LEDs. Please change the pin number two (red LED) to nine and three (green LED) to

ten.

Please open a new sketch, because we will use the dimmer function in the coming

chapters for our traffic light, but in this chapter, we just dim one LED.

Luckily, it is not very difficult to dim a LED. We need to learn only two things. First,

only digital pins of our Arduino with this symbol are capable of releasing different

currents. And the second thing is, that we have to use now the analogWrite()

function, because the digitalWrite() function only can send HIGH or LOW signals.

analogWrite(PIN, Value);

The analogWrite() function is similar to the digitalWrite() function. First you

claim the pin and then the value of the current (in range of 0-255, but only integer

numbers). You also can use HIGH (=255) or LOW (=0). For example, I want to dim

the red LED by 50%, then I write: analogWrite(REDLED, 127).

Please try on your own to dim the red and green LED to 75%, 50% and 25%.

Use our general construction: Setup variables, initialise variables and outsource

functions.


(do not worry if your code works, but looks different, there are many ways!).

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16 For-loop

Some more theory, but it is important to learn all about basic algorithms you will

always need in programming. The for-loop algorithm is needed to repeatedly

repeat processes with other values. For example, to check a list point by point to a

specific value.

The structure of the function:

for (initialization; condition; increment) {

//statement(s);

}

Example increasing LED brightness:

for(int i = 0; i <= 255; i++){

analogWrite(REDLED, i);

}

In the example, we increase the control variable i, and set the variable as the red

LED current (brightness).

So, you can use to increase or decrease a value and use every value in an algorithm.

You also can start other functions out of the for-loop. There are many ways to use

this loop!

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17 LED increase/decrease

Have a try and create a project with the given information from last chapter, which

will increase and decrease the red LED brightness every 10 milliseconds.

Hint: Use the if-then-else condition to check if the red LED is on LOW (=0) or HIGH

(=255). For the increasing/decreasing, use the for-loop. Use a control variable to

know in every moment, if the LED is LOW or HIGH. Do not forget about outsourcing!


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18 Traffic light with dimmer function

In this chapter, we will modify our traffic light sketch. We have learnt the last days

how to change the brightness of our LEDs and how to use the for-loop. In real life,

older traffic lights are changing colour with a dimming effect, because the old light

bulb does not turn off immediate, like a LED.

First, we open up the sketch from chapter 14. Do not forget to switch the pin

numbers of the red and green Led from 2/3 to 9/10! Now we locate where we have

to change or add something, for dimming off the current LED and dimming on the

other one at the same time.

For doing that we have to implement some new functions. We cannot use the

turnonofflights(int traffic) function, because this function just can decide

whether the red or green Led is on. The dimming function must be called earlier in

the checkButtonState(boolean btn, int traffic) function.

If the button is pressed we have to make sure that the turnonofflights(int

traffic) function do not change the colour immediately. Following steps have to

be done before the turnonofflights(int traffic) function operating:

Button pressed -> start dimming and colour change -> TrafficLightState = 0/1 ->

continue as known…

If you want, you can have a try first, but there is no shame, if you follow our tutorial

immediately…

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We are starting with creating to new functions, which are changing the colours with

the dimming effect. One for red to green and one for green to red:

The for-loop is increasing the brightness of upcoming colour and decreasing the

old colour in the same speed. The delay of one millisecond is needed, because

otherwise it will happen to fast in just milliseconds. With the small delay it takes a

quarter of a second, slow enough for our eyes.

Afterwards we implement these two functions in the checkbuttonstate(boolean

btn, int traffic) function:

We have to add the functions before the turnonofflights(int traffic) function

is called, because otherwise the LED is immediately on without dimming. Try to

optimise the dimming further on your own!


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19 RGB circuit

Last change for our breadboard. We will extend our circuit with another LED. Add

the blue LED as shown below. We need another 220-Ohm resistor, two cables and

the blue LED.

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20 LED back and forth

This task will be easy, because we use all knowledge, we learnt so far. Your task is

to program a chaser with our three LEDs: Red-Green-Blue-Green-Red each time the

button becomes pressed. Sounds easy, right?

For all of you, who feel still not comfortable, we will guide you through. If you are

interested in learning instead of copying, we recommend starting first on your own

and afterwards having a look to the following code! If you need help during trying,

each part of this chapter´s task is a separated part:

Button state

LED on/off

Chaser

Finish

We will improve the chaser in the coming chapters. Therefore, we need the basis we

are about to programme chapter.

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Button state

We have learnt on the previous days, how to read the button input and use the

information for executing the right function. We are keeping the introduced

structure with the control variable, which will get always the current state of our

button.

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LED on/off

Please do not forget about outsourcing and the “switch and case”-function! We

have learnt the basic way, how to turn on a LED, but we have continued with

outsourcing and improving this simple function. In this chapter, we write a function,

which turns on the right LED, if it is called with an ID (integer value). Do not forget

to turn off all other LED, which are not wanted to stay on.

We have added also the delay-function, because we need to halt the programme

after each colour change, otherwise we would not see a thing. The Arduino simply

works to fast for our eyes! Our LEDonoff()-function has also the possibility to set

different lengths of delay.

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Chaser

Now comes the new part of this chapter: The Chaser. The only thing we have to

program is which colour follows which colour. For changing colours we are using

the LEDonoff()-function, explained on page four.

Finish

Last but not least, we have to connect all functions, explained before, for finishing

our chaser programme. Call our Chaser()-function, when the button is pressed

(buttonstate == true). Everything else is ready to work!

Do not forget to implement all LEDs!


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21 While-loop

Last theory part for tutorial. We have already become acquainted the for-loop.

Now, we learn a new slightly different function for repeating an algorithm until a

specific point. The while loop works quiet similar to the for-loop, but with the

difference we are not increasing or decreasing a variable instead we are doing

everything until an event happens. For example, we are calculating random

numbers, as long as we will get the result two.

Please notice, that it should be always possible to reach the cancel condition!

Otherwise, you are forever trapped in the while loop! This can cause your computer

to crash!

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22 Chaser with while-loop

We will modify our chaser from chapter 20. Our goal is that the while-loop

controls how long our chase is going, after pressing the button. Last step of this

chapter is to change speed of the chase with progressing time.

We do not need to change anything from chapter 20 except for the Chaser()-

function. The while-loop controls the length of our chaser, but in the same time

we need the control variable (used as cancellation argument) also for running the

chaser back and forth (Red-Green-Blue-Green-Red).

As always, you have the chance to prove yourself and try it on your own first!

Hint: We need the mathematical operator: %. Instead of just dividing two

variables/numbers, it returns the decimal place. For example, 10 % 2 returns zero.

11 % 2 returns 0.5. This operator helps you to know, which way the chaser is going

(back or forth).

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First thing to do: Setting up our control variable. Because we use the control variable

also for running the chaser in different directions we need to set a start value. You

will see later, why two is better than zero.

We start with a length of 50 steps for our chaser, but feel free to change this value

on your own.

Now comes the content of our Chaser()-function. If the decimal place is zero, our

chaser will go red-green-blue. If not our chaser just alight our green LED to get back

to the starting point. The second goal is to speed up our chaser with progressing

time. We also can use the control variable “Counter” for this operation. Each time we

are increase “Counter” by one. The easiest way in our case is to subtract “Counter”,

multiplied with ten, from a start value (500). With progressing time, the delay

shortens…


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23 Chaser with while-loop and dimmer

We have learnt how to dim a LED, how to create a chaser and now we will combine

all this knowledge! Our goal is that we are running the same chaser like last chapter,

but every LED dims from HIGH to LOW before going to the next step.

Because you have all knowledge for this task, take your time to try it on your own.

Nevertheless, do not worry; we will give you some hints:

• Use last chapter´s sketch

• Use the for-loop for changing brightness

• Use very short delays to make decrease of the brightness visible

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We are about to finish or compare our solution with yours.

If you have not had any clue how to complete last chapter´s task, please open the

sketch of chapter 22. Afterwards focus on the Chaser()-function. We will replace all

LEDonoff()-function calls with a different one. First, we will modify our

LEDonoff()-function. We introduce a new variable “brightness” and all

digitalWrite()-functions are changed to analogWrite():

We want the LED to dim down to LOW (= 0) before the next step in the chaser

comes. Therefore, we are surrounding the LEDonoff()-function call with a for-

loop which runs from 0 to 255 (= HIGH). And each time the control variable of the

for-loop increases by one we call LEDonoff() with the brightness 255 minus

control variable:

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I guess it will dawn on you! It is as easy as it looks!


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24 Police flashlight

This chapter we will play a little bit with our

knowledge and our LEDs:

Open a new sketch and copy all functions of this/last

chapter´s task except the Chaser()-function. Replace

the call (“Chaser()”) in our loop-function with

“PoliceFlash()” and create the new function

“PoliceFlash()”.

We use now three while-loops. A “big” one for the

length of the sequence and two smaller ones for the

length of each colour (red/blue) flashing. In out two

“small” while-loops we are coding the flashing

sequence. All new police vehicles have a flashing

light, which is longer on than off. Because we want to

copy this sequence, we have to do equal. We use

delays to achieve this sequence:


Please give us a feedback on our website about your experience with this Arduino

Online Tutorial. Do you think we should publish more tutorials for an Arduino? Tell

us all! vote.ep-software.de/tutorial_rating

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Final codes

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“Let your Arduino speak to your computer”

“LED on! – Variable types”

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“LED on-off-loop”

“Press button -> LED on”

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“LED switch”

“switch-case function”

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“Traffic light”

“Dimmer”

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“LED increase/decrease”

“Traffic light with dimmer”

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“LED back and forth”

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“Chaser with while-loop”

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“Chaser with while-loop and dimmer”

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“Police flashlight”

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References

Images:

https://openclipart.org/detail/130657/awesome

https://openclipart.org/detail/307315/info-icon-

rounded

https://openclipart.org/detail/215664/computer-

guy-meme

All other images Self-made. Parts of them may include images

under CC0 license.

Code:

All code Self-written

Arduino Online Tutorials - EP Software

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