Transcript for:
Arduino Workshop Notes

are you trying to figure out how to  use arduino to build something cool   well hey you're in luck because in this single  workshop you're going to learn everything you   need to get started with arduino by the time  you're done here you're going to know what   hardware to get and why you're going to  know the ins and outs of an arduino board   you're going to understand which software to get  you're going to know the key arduino programming   functions to control electronic stuff and if  you've never programmed before you're going   to learn the key coding structures found in  all programming languages plus you'll learn   the best follow-on training to this workshop  to really accelerate your skills let's go before we start please do subscribe to our  youtube channel it doesn't cost you anything   but a click but it really helps us bring you  great content like this arduino workshop huge   thank you to altium for sponsoring this training  if you want to get a free trial of the super   powerful altium 365 software check the link in the  description thanks a ton i really appreciate that   okay so what the heck is this thing called arduino  well arduino is a tool that helps you control   electronic stuff with code so if you're building  a house you'd probably go grab a hammer well if   you're gonna build a project using electronic  stuff grab yourself an arduino but what do i   mean exactly by electronic stuff well let's make  two big general groups inputs and outputs inputs   are devices that gather information and outputs or  devices that have some action in the world so for   inputs think of things like temperature sensors  light sensors touch sensors flex sensors humidity   sensors infrared sensor distance sensors just to  name a few then you have things like outputs dc   motors stepper motors servo motors leds led strips  buzzers speakers lcd displays oled displays the   list goes on what arduino can do is stand in  the middle of these input and output devices   and control them with some cool logic that you get  to create so arduino can be used to read inputs   and control outputs okay so now you have a  general idea of what arduino is it's a tool to   control electronic stuff great okay but how do  you actually get started using arduino what do   you have to do so here's what you're going to need  we're going to talk about the big three it's what   i like to call the arduino trifecta you've got  arduino hardware the arduino ide and the actual   arduino code that you're going to need to write  so first we have the physical component of arduino   which is called an arduino board there's a bunch  of different types of arduino boards out there   when someone says arduino board it could mean a  number of these different circuit boards in just   a little bit i'm going to tell you exactly which  one to go buy if you haven't purchased one yet and   here's some quick good news if you have bought  one already it's probably gonna work just fine   now all arduino boards share one thing in  common they have a micro controller on them   a microcontroller is basically a really small  computer so when you use an arduino you're really   just using a microcontroller the microcontroller  is what enables us to read those different inputs   and control those outputs so again when somebody  says arduino board they're talking about something   physical it's this printed circuit board and it's  got some electrical components on it we'll dive   into this in a little bit okay so you're gonna  need an arduino board the next thing you're going   to need is the arduino ide that is the software  that you will use to actually write the code   that is then going to get loaded onto the  arduino board itself ide stands for integrated   development environment in just a moment we're  going to walk through downloading the arduino   ide to your computer it's totally free it's  pretty darn easy to use and it's an amazing   tool that's going to get you up and running  super fast alright the third part of this arduino   trifecta is the arduino code itself you're going  to need to write some code inside the arduino ide   that is ultimately going to get loaded onto the  microcontroller that's on the arduino board you're   using so the arduino code that you write is called  a sketch so that's like a little bit of jargon   there right so normally you write a program  well arduino they call it a sketch and this   arduino code itself is basically c and c plus plus  programming languages but it's got some arduino   specific functions and structure so when you  program an arduino you're basically programming   in c and c plus plus programming languages now  c code is blazingly fast it is used all over the   place from mission critical code on spaceships  to gpus running machine learning algorithms   if you are planning on learning to program arduino  and this is your first programming language   you should be super stoked because everything you  learn in arduino is going to help you understand   other programming languages it's not like  arduino some weird esoteric coding language   that has nothing similar to other languages and  it's going to give you a step up on learning to   code other languages like python java or whatever  you want to take on so those are the three things   you're going to need an arduino board you're going  to need the arduino ide and then you'll have to   figure out how to write the code that's going to  control this electronic stuff so we are going to   be diving into all three of those things i hope  you're pumped and excited to start learning a ton   so up next we're going to talk about what kind  of arduino board you should get and why if you're   looking for electronic parts for your design  you're going to want to check out octopart it   is a search engine for electronic components  and i'm telling you it's pretty darn amazing   it's like google for electronic components if you  want to find and compare parts quickly there is   no comparison you know when you're designing  something you don't want to get dragged down   by some clunky user interface trying to find the  right component octopart lets you keep your design   momentum going through moments when you used to  stop to research components with every search you   get super important supply chain information like  low stock levels and even life cycle validation   checks octopart is even integrated with altium  365 so you can get real-time insight as you   design make sure to check out octopart.com for  finding your next electronic part all right so   you need to go buy an arduino board but there  are a ton of options which one or ones are you   supposed to go buy to complicate things further  there's a ton of boards out there that say arduino   compatible what does that even mean are they going  to work with the arduino ide in the arduino code   okay if you have not yet bought an arduino board i  would recommend buying an arduino uno rev 3 if you   already have an arduino board and it's not an uno  don't worry about it it's probably going to work   just fine and we'll talk about why in a moment  so why do i recommend buying an arduino uno reb3   well here's the deal the arduino uno is the  best board for getting started with arduino   it's not the best board for all applications but  when you are learning to use the arduino hardware   the arduino ide and the code all at once then  sticking with the arduino uno is going to be your   path of least resistance and here's why it's super  popular so you're going to find tons of code out   there and training specifically for it it has 20  different general purpose input output pins called   gpio for reading inputs and controlling outputs  and this is plenty pins for most applications   plus the board layout itself is kind of the  standard that's used by most arduino accessories   called shields the only real annoying thing  about the arduino uno is that you'll need a   type a b usb cable like the kind you use with  lots of printers to connect it to your computer   so if you don't have one yet go get an arduino  uno rev 3 and i would recommend for your first one   actually getting it from the arduino website it's  a great way to support the arduino organization oh   crud but wait i already bought an arduino and it's  not an arduino uno rev 3 i got a mega or a nano or   this thing that doesn't even say arduino on it but  it sure looks like an arduino uno will these work   well here's the good news the chances are whatever  board you bought is probably going to work just   fine and that is one of the amazing things about  arduino and i want to take just a quick second   to explain something that eluded me for like  ever but hopefully it'll make sense to you   so arduino is the name of a company they started  making arduino boards and they made the arduino   ide and they helped make the underlying arduino  language but everything they did was open source   so the hardware like the actual design of the  board is open source hardware and what that means   is that anybody or company can use the exact same  design and change it if they want to and start   selling boards on their own so that's exactly what  has happened and tons of people and companies have   started selling boards that do the exact same  thing as an arduino board does or sometimes they   do additional things many times they do additional  interesting things so the arduino company and all   types of other companies sell tons of different  boards that all do slightly different things like   think of a car company that sells different types  of vehicles maybe it sells a minivan or an suvs   sedans or trucks each one serves a different  use case but for the most part they can all   get you where you want to go but it's not just the  hardware that's open source it's also the arduino   ide the arduino ide again that's the software that  you use to program the arduino is totally open   source and it's actively developed and supported  by the arduino company and the arduino community   but here's what's crazy the arduino ide will  work with these other companies boards just fine   so any board that you get that says it's arduino  compatible will very likely work just fine with   the arduino ide but here's what's even crazier all  the code that you write for one board is in most   cases going to work fine on another board with  maybe some slight modifications so if you wrote   code for your arduino uno but later want to switch  it to a smaller form factor like an arduino nano   it's not like you need to rewrite all of your  code at most you might need to adjust a couple   lines of code and you're gonna be ready to roll  okay i know that was actually quite a bit there   hopefully you've kind of got a bigger picture of  what arduino compatible actually means and again   i recommend getting yourself an arduino uno r3 if  you're just getting started now what if you don't   have any cash at all like zero cash but you still  want to start playing around with arduino well you   actually have a free simulator option you can get  access to a really nice free arduino simulator   at a website called tinkercad.com tinkercad is  created by autodesk and they have built a really   nice arduino simulator so you can use an arduino  uno board you can build small circuits test them   you can write code right inside the simulator it's  pretty darn cool a lot of people find they like   it a ton now it does have some limits like you're  not going to find all the different parts in there   and there's not a ton of different arduino boards  you can use but for just getting started it is a   great place to go if you're strapped for cash so  now let's take a look at an arduino board and talk   about the stuff that's on it like have you ever  rented a car and you check out its features like   what side you put the fuel in where do you adjust  the mirrors like that kind of thing that's what   we're gonna do here so what i've got is an arduino  uno here this is what we're going to use as our   base for talking right first thing first the whole  thing together is called a circuit board yeah i   know you probably know that but hey just in case  the most important thing on this circuit board is   this big black rectangle that has a bunch of metal  prongs sticking out this is the micro controller   and again it is the most important part of the  arduino board in fact an arduino board is a micro   controller development board it's designed for  you to take advantage of all the cool features   on that microcontroller now depending on the board  you have the micro controller might look a little   different it could be smaller and the metal prongs  may be really tiny not to mention it could be a   completely different microcontroller than the  one on the arduino uno and just as a reminder   the microcontroller is the brains of the operation  here it's what's going to be taking the code you   write and applying the logic so those metal prongs  i was talking about those are called pins these   pins are how the microcontroller communicates to  the world many of the pins can be configured or   like set up right to be inputs or outputs for  reading sensor values or for controlling stuff   and those pins are called the gpio that stands  for general purpose input output now the way the   output pins work is by adjusting the voltage at  the pin the way the input pins work is by reading   a voltage applied at the pin now if you look at  the board like the periphery you'll notice these   plastic columns filled with holes these are  called pin headers or just headers and they come   in different shapes and sizes but a lot of them  look just like this each one of the holes makes   an electrical connection to one of the pins that  we were just talking about on the microcontroller   and those holes are designed to make an electrical  connection with wires and components so you can   stick something into that hole like a wire or  resistor or something like that and you don't have   to solder stuff to the microcontroller you can  just make a temporary connection using this pin   header now let's say you have an input device like  a button you can hook it directly into one of the   pins on the arduino board or if you have an output  device like an led you can connect that directly   to the arduino board as well oftentimes people use  a breadboard when they're working with an arduino   that's a place where you don't have to solder your  circuit together you can use these little wires   called jumper wires to make different connections  they're super handy if you don't have one i would   recommend getting one of those as well now  depending on the arduino board you have the pin   headers may be labeled let's take a close look at  this arduino uno which has labeled headers on one   side we have the digital pins labeled 0 through  13. these pins can be used for reading on off   type inputs like if a button is being pressed or  if it's not being pressed we'd call that a binary   input not only can they read inputs but they can  also act as outputs which means they can source   voltage so if you turn a pin on which is called  setting it high then the pin can source 5 volts   if you turn it off called setting the pin low then  it can source zero volts and what this allows you   to do is control different electronics like leds  buzzers and it also allows you to communicate with   other devices using different protocols now  some of these pins have special purposes for   example pins 0 and 1 are used for communication  with the usb port they're marked with a tx for   transmit and an rx for receive there's also two  tiny leds on the board marked tx and rx and those   leds will flash on and off when signals are being  transmitted on those two pins some pins also have   a little squiggly line next to them those little  squiggles mean that the pin is capable of pulse   width modulation or pwm and what pwm does is turn  the voltage high and low at different frequencies   and this is useful for driving inertial loads like  motors and also for fading leds on and off as well   as controlling things like servo motors now if you  look at the other set of pin headers on the other   side of the board you'll see two sections one  marked for analog in and one for power the analog   in section has six holes and these are places  where you can connect and read analog inputs so   before remember we said the button is either on  or off that binary input well analog is when you   have a continuous signal and there's lots of  sensors out there that have analog outputs to   read those analog outputs you can use these analog  input pins and that's because the microcontroller   has an analog to digital converter on it called  an adc these pins right here are connected to the   microcontroller's adc an example of a sensor that  might output a variable voltage is a temperature   sensor so as the temperature changes in the room  or wherever the voltage at the output pin of the   temperature sensor is going to adjust and if you  have that output pin connected to the analog input   pin then you can read that variable voltage and  then use code to translate it from a voltage to   an actual temperature next to the analog  in section we have the power section here   you'll find two pins marked g and d gnd stands for  ground and that's the lowest voltage on the board   you'll also see a 5v and a 3.3 v pin the v  stands for voltage which you probably guessed   and you can use these as a voltage source for  small components you connect to the arduino board   as long as they don't draw too much current now  we're going to skip all the other pins for now and   talk briefly about how you can power this arduino  uno there's generally three recommended ways you   can provide power through the usb port you know  just by like connecting the board to your computer   or you can power it through the dc jack so that  dc jack there is a 2.1 millimeter center positive   plug and you can connect a power supply to it  like say five double a batteries or one of those   wall wart supplies the voltage limit on this dc  jack is about 7 to 20 volts but you're better off   limiting your voltage to about 12 volts and  that's because there's a voltage regulator   on the arduino board and if you supply a ton of  voltage then it has to dissipate a bunch of heat   and that's just lost power and excess heat  that you don't need so i'd limit it to a 12   volt output i'd also recommend a minimum output  current of one amp that's a thousand milliamps   more is okay but less can be an issue if you start  hooking up a bunch of stuff to your arduino board   now if you look at that power section again  on the pin headers you'll see a pin marked   v in this is where you can hook up an external  voltage source to the board in order to power it   this has the same limits as the dc jack so we're  talking about that 7 to 20 volts again limiting it   to 12 volts is a good idea the final pin i want  to talk about is the reset pin if you apply a   low voltage to this pin it will reset the arduino  board same thing with that reset button when you   press it that's going to reset the board as well  and that's like turning the power off on like some   electric device right you just turn it off turn  it back on again which is totally fine to do with   an arduino board all right i know that was a ton  you probably have more questions than answers the   truth is there is a ton to learn we just barely  scratch the surface with all the stuff that's   going on with an arduino board but hopefully that  gives you a taste of the most important things you   need to know on the arduino board right now you're  going to have a basic footing so that we can start   writing some code and actually make this arduino  board do some stuff now in order to get code   onto this arduino board we're going to be using  the arduino ide next what we'll do is get the   arduino ide set up so that we can start writing  code and get it loaded onto the arduino board   we'll run through a couple example sketches just  to give you an idea of how this whole thing works   all right so what i've done is navigate to the  arduino website that's just arduino.cc and then   i clicked on this software navigation tab and  that takes me to this page where it shows kind   of a bunch of different options for different  ides so as a reminder ide stands for integrated   development environment and it's simply a software  tool that you're going to use to write your code   in and it's also going to help you load the code  into an actual arduino board it's a really handy   tool and all the options on the arduino website  are free and when i say options you actually   have three different options on this website for  what ide you want to use they have the web editor   they have the original arduino ide which is  arduino ide 1 and then they have the future   version of the arduino ide which is arduino ide 2.  now arduino ide 2 is still in development as we're   speaking but it's definitely working and you can  download it and check it out i think it's a great   ide i'm not positive yet but i actually think  they're going to keep both of these ides around   for a long time so i don't think ide 1 is going  away i think it's got a lot of great features it's   really simple to use nothing really gets in your  way not to say that arduino ide 2 isn't great also   but it has a bit more going on than arduino ide  one now arduino ide one and two are both downloads   that you would download onto your computer you  know load onto your hard drive and use but they   also have a web editor that you can set up and so  it doesn't matter what computer you're on you can   write code for your arduino and you can upload the  code that you write in the web editor onto your   arduino boards with your computer what's great  about the web editor is if you have a chromebook   or maybe you're in an educational environment a  lot of people have chromebooks then you can use   this web editor on those chromebooks so let's go  through the process of downloading this arduino   ide one it's gonna be the same for arduino ide two  but let's just do this so i'm on a windows machine   click this you have the option to donate  i'm just gonna download it for now   i'm going to download it to downloads i'll double  click the exe file i want it to make changes   something about selling your first kid  i'm just going to leave all these checked   i'm just going to leave it as this default  destination folder under program files all right now it's completed i'll go ahead and  hit close all right now i've got a shortcut right   on my desktop here if i click this it's going  to open up the arduino ide i'll allow access   all right here we go this is not super duper  fancy but this is it right here so when you   open up the arduino ide it opens up a new  sketch it creates a new sketch for you with   the date in there and it fills it with  two functions void setup and void loop   which you'll learn about here shortly but what's  really important is about where these things get   saved so what i'm going to do is i'm just  going to go ahead and save this file save all right so i'm saving this the file name is  going to be sub sandwich i'm going to hit save   so now what i want to do is show you where  that actually gets saved so i'm going to go   to my documents and if we come to documents when  you install the arduino ide it creates a folder   called arduino and if you open that folder  up there's going to be some files inside here   so libraries is where all the libraries that you  save will go and all the other sketches you save   it's going to create a folder with the name of  the sketch so we save sub sandwich and if you   open that it's going to have a file in here and  you can see the file name is also sub sandwich now   the file extension is dot eno old file extensions  are dot pde but dot eno is what you'll see   in this folder named arduino this is called your  sketchbook folder so if you go to file sketchbook   you'll see here's two programs in here now i had  already downloaded the arduino ide and i had a   little simple write program so that's why this  shows up but if you want to get to the programs   you've written which are called sketches in  arduino you would just go to sketchbook and there   they would show up but let's go to file and let's  go down to preferences and i want to show you this   right here this is where you set your sketchbook  location right now mine is under users mica   documents and then arduino and you can change that  here if you want you can also change the font size   like we could make the font size bigger which i  usually do so we'll make that 18. you can display   line numbers if you want so you'll see this when  i save this here but there's some important stuff   that takes place in here we won't talk about  all of it right now but i'm just gonna hit ok   and now you can see we see the line numbers okay  cool all right so let's go ahead and check out   one of the cool features of the arduino ide and  that is all the example sketches in here so i'm   going to go to file and i highly recommend  you do this as well and i'm going to go to   examples and in the examples they have a bunch  of example programs a bunch of example code   that you can play around with so i'm going  to go to basics and i'm going to go to blink   it's going to open up a new program new sketch  here and they've got some comments up here   comments are things that tell you about the  program but they there it's not actually code it's   just more like help or text for you to understand  what's going on and blank turns an led on and off   so we won't talk about this code right  now but i just want to show you how to   check to see if there's any errors in the  code and then how to actually upload it onto   an arduino board so the first thing i'm going  to do is i'm going to take my arduino uno and   i'm actually going to plug it in with that usb  cable to my computer so i'm going to plug it in   now my computer made a little noise like oh hey i  recognized something yours may or may not but mine   does and then i'm going to go up to tools board  and i'm going to select which board i have now   i have an arduino uno so it already recognized  that for me so i'm just going to click that   we also need to set the port so here's the port  it's going to show me i have com4 hooked up i   have an arduino uno maybe i have different things  shown here right but there might be multiple ports   listed here i'm just going to go with this  one right here so i'm going to click that   so now that i have my board and my port selected  i'll be able to upload this code onto my arduino   now if you look in the bottom right of the  arduino ide it'll tell you what board you have   and what port it's on and then this space right  here in this black space this council space it's   going to show you if you have any errors or  anything like that so the first thing i'm   going to do is hit this little check mark this is  the verify and what it's doing is it's checking   your sketch for any errors now since this is an  example sketch we're not going to see any errors   so we get a little message down here about how  much space it's using and we're doing just fine so   now i want to actually get it onto my arduino  board so i'm going to go ahead and hit   upload now when i hit upload now it's actually  uploading it to my arduino board and if you   look at your board while it's uploading you'll see  the tx and rx lights start blinking now what this   program does is it blinks an on-board led on the  arduino uno so most arduinos they have an led on   the board somewhere usually it's a pin 13 but not  always and as you can see right now we're blinking   the led so we are able to successfully upload this  to the to the board and so it's on for a second   and off for a second but if let's say we wanted to  speed that up we could mess around with this delay   function and we'll talk more about this later so  don't get too worried but i just want to just show   you how how this can work so i'm just going to  make that 100 and this let's make it 75 and then   i'm gonna go ahead and upload it again so now i  can see the led is blinking much faster and it's   not off as long as it is on so it's kind of a neat  little effect okay so that's uploading code to the   board that's not too crazy right so that's about  everything you need to know on a very basic level   about how to get code loaded onto your arduino  board i highly recommend going into file examples   and just walk through each of these examples see  the circuit they talk about setting up and then   playing around with those circuits just doing that  is really going to help you find your way around   alright so this is arduino ide 1.0 for  kicks let's check out arduino ide 2.0 all right the license agreement i'm going  to install it for everybody uses a computer   and i want to say yep that's  okay again selling my children   now what's nice is you can have arduino  ide 1 and arduino ide 2 installed on   your computer at the same time no  issues there so i'll get hit install and then i'll just click finish all right and  it automatically opens the arduino ide 2.0 for   you now i had already had it installed you might  have to click to install some drivers while you go   through that process but it's just acknowledging  that some drivers are getting installed   and it looks pretty darn similar doesn't it  so you're going to have file and preferences   and you'll notice that the sketchbook location  is the same for ide1 and for ide 2. so when you   save a sketch in idd2 it's going to also  you'll also be able to access it from ide1   no problem at all okay and you can also you  can change the theme to a different you know   colored theme in there too if you wanted  to do that kind of fun to do i'll just keep   it with this theme now if i want to connect a  board i can just go to tools board and select   my board notice this is arduino avr  boards there's different types of boards   that you can have show up here we won't  cover how to show the different boards but   got a really big list here and i'm just going down  saying yep arduino uno and then i go back to tools   port and the only port is showing me is currently  this com4 arduino uno port so i'll select that   and then you'll notice just right here it's going  to show me my options if i had other boards here   it would show me those and then again down in  the bottom right it's telling me what board i'm   connected to and the port that i'm on the verify  button is the exact same and the upload button is   also the same so i can go to file sketchbook  i can see there was that sub sandwich sketch   that we had saved i can go to examples and see  all those examples i'll just go to blink again   now in arduino id 2.0 this is going to open up  a new window so go ahead and open this up it's   the same sketch nothing different there and just  verify that yep this is the port i've got selected   and i can go ahead and upload and the output  shows down here all right and that's pretty much   arduino ide 2.0 so pretty darn similar huh not  too much different there now let's talk about   the web editor so go ahead and click code  online and what you have to do is set up an   account i've already done that all right so here  i am now i'm logged in to the arduino web editor   but in order to actually upload a sketch with  the usb port you have to install some software   it's the arduino agent so this little thing pops  up i'm just going to go ahead and click that and   it's going to walk me through setting it up making  sure it's installed so i'm going to install the   agent and then select for windows 32 or windows  64. i've got a win64 so i'll download for that   i'll double click the installer just hit some next   yep i'm gonna accept selling my kiddos that  looks like a good installation directory   all right i am planning on using this with google  chrome or firefox so i'm i'm not gonna click   yes this is these are the two i plan on working it  on so here we go and now i'll hit next it's going   to go ahead and install that and then it launches  the agent it just kind of runs in the background   finish it now when you look down at  your toolbar you'll see this little   arduino looking thing and this is the agent right  here so you can actually click this it's going to   take you right to the web ide if you go to  the create it'll open up a tab for you and   what we're going to be working with is  the web editor all right so now i'm i'm   all connected all right so now what i do if i  want to select the board is i just click here   and it's going to show me the boards i  have so here's an arduino uno i select that   cool and then over here it's got the different  things so i can go to examples basics blank   here's that sketch that we just saw on our  desktop same thing here and then i'll click upload same thing happens the tx and rx lights turn on  and off and i have successfully uploaded the board   so same thing here and when you save sketches they  get saved over in your sketchbook folder but this   is an online sketchbook folder so you know i've  used this before so we've got some code in here   but it just gets saved over in here and you can  organize it you can access these from anywhere   so that's pretty cool so which one of these are  you supposed to use well here's the good news it   doesn't really matter just pick one and go with  it now if you are on a chromebook computer then   you're gonna have to go with that arduino web  editor but otherwise you know ide ide1 ide 2 it   doesn't really matter there's also other editors  out there that you know we're not going to talk   about right now that you could write this code on  for example vs code you could use platform io the   code's going to remain the same it's just a matter  which ide you feel most comfortable programming in   all right here we are in the arduino ide  and this is the stuff we're going to go over   how every arduino program is laid out how to  use variables how to use control structures   and we're going to be talking about all the  most important arduino specific functions   as we go through this so the first thing we're  going to do is go ahead and open up a new sketch   we're going to talk about how an arduino program  is laid out so here's a new sketch and what do you   notice there's some words here some stuff well  this stuff these are functions and the reason   we know their functions is they've got these  open and closing so here's an open and here's   a closing parenthesis after a word so that kind  of setup when you see an open closing parenthesis   maybe some stuff would be in here that's going  to give it away like hey this is a function so   the name of this function is called setup it has  an opening curly brace and a closing curly brace   same thing with this function this function is  called loop and it also has an opening and closing   curly brace now you can forget this word void  don't worry about that but these two functions   set up in loop need to be in every single  arduino program you write if we read the   information that's in here it says put your setup  code here to run once and in loop it says put your   main code here to run repeatedly well what does it  mean to run code what are they talking about well   that just means that if we write any code in here  it's going to execute the code and it's going to   execute the code from the top to the bottom so if  we have code 1 code two it's gonna execute code   one first and then the next line of code code two  and it's gonna go on until it gets to the end and   once it gets to the end setup is over and then  it moves on to the loop so setup runs once and   the code you'll put in here is stuff that only  needs to run once it's like code that's going   to set up the other part of your program now  the loop it's going to run over and over again so in loop it also starts at the top and it's  going to work its way down first it's going to   execute this code on line 9 and then this code on  line 10. of course this is in code this is just   gibberish but i'm just trying to give you an idea  then it gets to the bottom curly brace and when it   gets here it starts back up at the top and it runs  this code step by step and it's going to do that   forever that is it just repeats the same thing  over and over and over until either you remove   power from the arduino board or i don't know  the universe ends in heat death now you might   be thinking wait a second how can a program  that does the same thing over and over again   actually do anything really useful doesn't  that kind of limit it to doing simple stuff   now first blush you are totally right but what we  can do as programmers and where it really gets fun   is we can use variables and control structures to  change how the program reacts and so you're able   to get extremely creative diverse logic that can  control things from graphical user interfaces to   countdowns to just about anything you can dream  up so these functions void setup and void loop   are extremely important they are going to be  in every single one of your arduino programs   in fact if you leave one of these  functions out you're going to get an error so now we don't have the loop function let me  verify and we should see an error down here   and we get an undefined reference  to loop which is just saying hey man   stick that loop in there okay so this is how  every arduino program is laid out with setup and   loop all right so now let's talk about variables  these are super awesome tools that you're going to   be using in just about every program you write a  variable is like a bucket that allows you to store   information in it like say we wanted to measure  the temperature with a temperature sensor   when you store the value from the temperature  sensor you would put it into a variable making   a variable is simple and storing information in  a variable is really simple you need four things   you need a type a name an assignment operator  which is just an equal sign and then the value   that you're actually going to store into the  variable so let's go through each of these items   again that's type a name an assignment  operator equal sign and then an actual value   the type it's also called a data type is the kind  of information that you're actually going to store   in the variable and there's a bunch of different  data types and i have them listed right down here   if you want to pause the video you can take a look  at them so you've got boolean types those are like   true false values so with a boolean there's only  two options it's either going to be true or false   zero or one but technically zero is false and any  number other than zero would be evaluated to true   and then you can also have high and low so high  is true and low is false so those are examples   of boolean variables then you have a byte that's  just a small number from 0 to 255. so a lot of   times when we're referring to those pin numbers on  the arduino i'll save those as a byte because it's   just a small number and it doesn't take up a lot  of memory so the more the variable can store the   more memory it takes and a byte is a pretty  darn small variable and that's why i use it   for something like a pin number larger numbers  are can be integers and that type is just int   just like up here boolean would be b-o-o-l so that  is the type you would write out before the name so   integers can store negative values to negative 32  000 and some change up to 32 000 and some change   and then for bigger numbers you can use a long  and you just type the word long and it's a longer   number it's like all the way up to 2 billion and  some change and all the way down to negative 2   billion and some change that's a huge number and  then a float is going to be a number that has a   decimal point and then if you want to store a  character something that's going to actually   be displayed on text like say on an lcd screen or  a computer monitor you'd store it as a character   and you store single characters as c-h-a-r  car stands for character and you use single   quotes and then if you want to hold a bunch  of characters like let's say you're storing   somebody's name or or maybe the name of your  wi-fi network you would use a character array   and that's going to be name and then these  open and closing brackets these square brackets   and then you use double quotes for storing that  whole line of text right there and this is what   we'd call a string now it's different than capital  s string that you'll see in the arduino language   but we're not going to be talking about that  now we're just gonna say uh we're just gonna be   using character arrays to store strings so that's  what i mean when i say type what about the name   well the name of the variable is just  how you're gonna refer to it in your code   variable names can contain letters numbers and  underscores but they can't start with a number   and you can't use emojis in your names bomber but  you can use descriptive names for your variables   so using something like current temperature  would be more clear than just writing the   letter c t or something like that now to actually  store a value into the variable you need to use an   equal sign which is called the assignment operator  so here it is right here the assignment operator   throw out all the algebra you know  because this has nothing to do with that   when you see this it says take the value over  here and store it into this variable's bucket   that's what it's saying so it's going to evaluate  this and this doesn't have to just be a value this   could be an expression over here so it's going to  evaluate this expression and save it right here so let's say i had two variables here one is  called taserblast and it's set equal to eight   and then the other one is called pain  threshold and notice i set it equal to   this expression right so this is taser blast so  this is referring to this variable so this is the   number eight and we're saying well what's eight  divided by two that would be 4 right so now pain   threshold would be holding the value 4. now to set  up a variable the first time all you really need   to use is a declaration so that is the type and  the name so we could do something like taser blast   that would be a declaration and once you've  declared it then you can use it in your code just   by using the name so then we could do something  like this we could say taserblast equals eight   we don't have to include the type anymore because  we've already declared the type so now the program   knows oh hey taserblast is an integer it's a  variable that stores an integer and here we   are assigning the value 8 to it but you can also  do that all in one line and that's a declaration   and initialization all in one so taser blast  equal eight so here we are defining it and we are   initializing it to eight now finally one thing  you might be wondering here is what about this   semicolon here you see a bunch of semicolons right  well any time you've finished with the statement   in arduino that is you're like finished with your  line of code then you end it with a semicolon   so a lot of programming languages they use spaces  between lines to delineate one statement of code   from the next but arduino which is based on c  and c plus is not one of those languages it uses   semicolons so for example we could break this line  up into this right here so notice how these are   on two different lines but since the semicolon is  here when we verify the program the compiler which   is part of the ide which is going to be checking  for our code looking at our code for errors   it's going to start on line 5 but it's not going  to see an end of this statement until it gets to   that semicolon so this is fine in fact this is  fine but normally you'd see it like this okay   so variables they're like special purpose  buckets and they can hold and store values   let's look at an example program that uses  some variables so i'm going to go to file   examples basics fade and let me clean this up  real quick just so we can see a little bit better alright so check this out we've got three  variables up at the top above setup and when   a variable is above setup it means it can be used  by any function inside the program so it's called   global when it's up here so like i said here's  three variables and we see that they are declaring   and initializing each one of these variables so  all of them are of what type integer right and   then each one has a name so one's called led one's  called brightness and one is called fade amount   they assign the value nine to led and here  it says the pwm pin the led is attached to   so they have a circuit that might look  something like this they've got an led   one side of the led is connected through  a resistor to pin 9 which is capable of   doing pulse width modulation the other side of the  resistor with the short leg is connected to ground   then they have a variable called brightness  set to zero and a variable called fade amount   set to five so let's just take a look at the  rest of this program we're going to find some   really interesting functions in here so here's  setup you'll recall setup runs once and there   is a really important function inside setup here  called pin mode so if you'll recall the pins on   the microcontroller are how they interact with  the outside world and we can access those pins   through the headers on the arduino board right if  we want them to be inputs we need to use this pin   mode function to set them as inputs if we want  those pins to be outputs like turning on an led   we need to set those pins to be outputs and the  way we do that is in setup because it only needs   to happen once and we use this function called  pin mode now you should notice that pin mode is   a function right because it's got a name and  then it's got these open opening and closing   parentheses you also notice that it changes to a  specific color and this means that it's an arduino   specific function it's like a special function  that arduino is using and pin mode takes two   values it said that you pass in values to this  function the first value is led so what was led   well that's a variable name and we had set it  equal to nine so we're passing the value nine   to pin mode and then we have a comma and  then we're passing this keyword output and   what this is telling the arduino is hey pin 9  on that microcontroller needs to be set as an   output that way it can source voltage so pin  mode super important arduino function so what's   the first thing that happens in the loop well we  come to another really important arduino specific   function called analog write we know it's arduino  specific because it turns orange like this or it   highlights in a specific way now depending on the  ide you're using maybe it doesn't highlight but   anyway you know it's a function because it's got  these open and closing parentheses and you'll   notice we pass in some variables some values here  now what analog write does is for the pins that   are capable of doing pwm pulse width modulation  it sets the duty cycle so if you recall with pwm   we're adjusting the on and off time of that pin  very rapidly and we can adjust the average voltage   of the pin between 0 and 5 volts but it's on a  scale and it goes from zero to 255. so this first   value led is referring to the pin number that we  want to apply the pwm at so what was led oh that's   right we set it to nine so this is the value nines  we're saying hey pin 9 we're going to pwmu and now   it says hey well what is the amount you want to  set the pwm tube somewhere between 0 to 255. if   we set it to 0 this would have an average voltage  of 0. if we set it to 255 the average voltage   would be 5 volts and somewhere in between there  you know like what 127 or something like that   that would be two and a half volts so you can use  anywhere in that range and again it's adjusting   the actual duty cycle so the on and off cycles of  the pin all right again super important function   analog write arduino specific you can use it  to set pwm for a pin okay so we've talked about   pin mode and analog right so far now what's  this next line of code here well look at this   we're doing another assignment so we're saying  hey brightness that was a variable we made right   what was this brightness was equal to zero so it  says brightness is equal to brightness plus fade   amount that doesn't that look like weird algebra  well remember it's not algebra the assignment   operator is saying take the stuff on the right  side of the equal sign evaluate it and then store   it in this variable so here we have brightness  well what is brightness well it was zero right   so this is zero plus another variable fade  amount what's this well it was set at five   so what's zero plus five that gives  us five right so now brightness   is now five so brightness is five okay that's  interesting so on line thirteen we were pwming   pin nine and we're saying the brightness was zero  so that led would be off so now what we need to   do is start talking about control structures a  control structure allows you to adjust the flow   of your code if we go to the arduino reference  page and we go to structure when i'm talking   about control structures i'm talking about these  right here so we have an if statement force else   whiles switch cases these are the control  structures that are going to allow you to   have your code do different things depending on  different circumstances so let's go back to that   code and we'll see we have this if statement so  this is some control code and notice it's followed   by an opening and a closing parenthesis and inside  this is called our condition so if statements have   a condition if the condition evaluates to  true then the code inside the curly braces   gets run if the condition evaluates to false then  all the code in here just gets skipped over so you   only do the stuff inside the curly braces of an if  statement if this is true now you might be looking   at this and being like wait what is going on here  well we've got two things going on so this right   here is actually an or symbol so this condition  is saying if the brightness variable is less than   or equal to 0 or if the brightness variable is  greater than or equal to 255 then do something so   well why don't we just evaluate well let's pretend  we're the arduino and let's evaluate this so   what did we say we said brightness was 5. so if  brightness is 5 is 5 less than or equal to 0 nope   it's not okay well is five greater than or equal  to 255 nope it's not so that means we're just   going to skip over this line of code right here  the first time through the loop right okay so   we've controlled our code flow because we  haven't used this based on based on a condition   so then we get to this next line of code and it  says delay 30. here's another one of those super   important arduino functions that you'll learn to  love and hate it's called delay and what it does   is it stops the program in its tracks no other  code will run for the amount of time you put in   here and this time is in milliseconds so for 30  milliseconds we're going to say stop don't do   anything arduino board and when we say stop don't  do anything what we're saying is don't execute any   more code because what we did up here on line 13  when we pwm'd pin 9 to a value of 0 that means the   led was off right it's there's no brightness  there and we're just gonna hold that position   so delay is kind of like hold it hold it okay go  that's what's going on here so after the delay   we get to this final curly brace here's the end of  this loop function and what do we do we start back   up at the top so we're back at the top we run  into our friendly function analog write again   using the pwm feature of the microcontroller  and what is brightness this time well if you   recall last time through we changed brightness to  five so now brightness is five so that increases   the on time for the duty cycle and that means  this led is going to be on ever so slightly   so now the led is going to turn on dimly now it's  not going to turn on dimly because we've applied a   lower average voltage to it it's actually going to  come on dimly because of the ways our eyes work so   the led is going to be flickering on and off at  a rapid pace it's not going to be like somewhat   on and somewhat off it's going to be full on  and full off but the frequency of it coming   on and off tricks our eyes into thinking that it's  actually dimly lit and that's how pwm works with   leds you're able to make a fading effect of the  led by adjusting the duty cycle of that pwm signal   all right so we can see the led dimly well down  here what do we do well now we're going to take   brightness that was five right and we're setting  it equal to brightness plus fade amount well what   is brightness well you might be tempted to think  well hey yeah we set brightness to zero up here   well actually brightness got updated before so  we're you we're working with the newest the latest   and greatest brightness which was five right so  five plus fade amount which was set to five so   that's ten so now brightness is equal to ten now  we come back down to our if statement and we are   checking the condition but the condition really  hasn't changed right because 10 isn't less than or   equal to zero nor is it greater than or equal to  255. so again we're just going to skip this code   now we delay we say it hold it everybody we come  back and you can see we're just going through   this over and over again and what is happening  well what's happening is brightness this value   because of line 16 it keeps increasing it  gets bigger and bigger and bigger and so we   see this led fade on slowly it's going to get  brighter and then brighter and then brighter   so we're going to see it fade on from dark to  brightness well what happens when this value gets   to 255 well when this value gets to 255 then this  if statement this condition is going to be true   because brightness will be equal to 255 which  means the code in here is going to run so our   control structure is going to affect that flow  when brightness gets to 255 and what does it do   well it flips the sign of fade amount so it's  this fade amount which was five it sets it equal   to negative fade amount which makes it minus five  and then we delay so that's interesting minus five   okay so we said brightness was 255 right  so we come up to this loop brightness is   still 255 so that led is going to be like fully  bright fully lit we come down to brightness now   brightness that's 255 plus negative 5. so what's  a positive number plus a negative number well you   basically do a subtraction so now we're going  to go down to 250. so now we'll be going from a   high brightness to a low brightness because fade  amount is negative so we'll be subtracting from   brightness until we get down to zero and then this  if control statement is going to flip it again   and then we'll add and it's just going to go back  and forth forever and ever and ever and that's   just a basic idea of how this flow works so let's  look at another example of a control structure   let's look at a switch case statement here's  an example of another control flow mechanism   function called switch case and what we're  doing here is we have a sensor hooked up   to one of our analog pins and if you recall  the analog pins are connected to the analog   to digital converter on the microcontroller so  pins a0 through a5 6 pins on arduino uno using   that adc and what that adc is able to do is take  an analog voltage and convert it into a number   between 0 and 1023 so what this program is doing  is it's going to read the value of the sensor   and then based on what that input in is it's going  to print out something different to the serial   monitor now we haven't talked about the serial  monitor but we are in a second because it's super   important when you're using the arduino ide but  let's start at the very top here look we've got   two variables they're both integers one is called  sensor min and one is called sensor max sensor min   was assigned to the value zero and since our max  you see we've initialized it to the value six   hundred but what's this const in front well this  is constant and what this is saying is hey these   variables aren't going to change throughout the  program this is called a qualifier and you'll see   this pretty often you only use this for variables  that don't change okay here we are in the setup   and we see a super important function called  serial dot begin so there is a code library   called the serial library and begin is a function  that's part of that library and so to use the   begin function first we write the name of the  library which is serial we have a little dot   and then we follow with the name of the function  begin and we're passing into it this value 9600   which is the baud rate all seems kind of odd just  a lot of details here i'm kind of skimming over   but essentially what this does is it allows us  to communicate on the serial port between our   arduino board and our computer so there's a tool  built into the arduino ide called a serial monitor   open it up right now and what it does is it allows  us to display text from the arduino board to our   computer okay so serial begin initializes that  serial communication super important function   don't worry about the 9600 now just go with it  again it's just the rate of communication okay   so we go through setup then we jump into the loop  what's loop do it it goes over and over and over   again and what are we doing here inside the loop  well it looks like we are declaring a variable   and initializing it to a value so we're making  an integer we're calling it sensor reading and   we set it equal to what what is this well this is  a function right we see the name and then we see   these parentheses here analog read is another one  of those super duper important arduino functions   analog read uses those analog pins so analog pins  zero through six and it allows us to use the adc   to read a voltage but all it needs to know is hey  what pin number do i need to read that voltage at   and so we're saying pin a0 so if you want to refer  to those analog pins you can use a 0 a 1 a 2 a 3   a 4 a 5 so you just put an a in front of the  number now we could have said we could have made   a variable out of this we could have made a byte  called sensorpin and set it equal to a0 we could   have made it a constant since it's not going to  change and then we could have taken sensorpin and   put it right here just like that so now what's  going to happen on this line of code is that   analog read is going to look at this sensor pin  pin a0 it's going to read the voltage and whatever   the adc returns it's going to be a number between  0 and 1023 it is going to store it into sensor   reading so now sensor reading is going to be equal  to whatever that value was line 14 a little bit   confusing it's using a map function now this isn't  this is a arduino specific function it's not super   duper important it's still useful what map does  is it takes one range and it converts it into   another range basically what's going to happen  is you pass in the existing range and then you   want to transform it into a new range not going to  go into it now but basically what it's going to do   is it's going to squish down the number so as that  sensor value changes we're either going to get a   0 a 1 a 2 or a 3. and that's when we finally get  to this switch case here so the switch notice that   there's a parenthesis following it and inside  there is a value and this value is going to   determine which case we actually take on so here  we've got case zero so when the value is zero   we're going to execute this code when the value is  1 we're going to execute this code when the value   is 2 this code and when the value is 3 this code  notice the break statement after the case that   says hey when you get to the break statement  it's going to jump us out of that switch case   so you're only going to do one of these cases so  in this loop we're going to read the value at the   sensor we're going to map it to a small condensed  range and then we're going to do something   based on the value and in this case we're using  the serial library again but we're using the print   line function from the serial library and this is  what is actually going to print something out to   the serial monitor window so after we get down to  the end of the switch case we have a short delay   just one millisecond and then we jump back up  to the top of the loop and what do we do well   we read the sensor again well why would we read  the sensor we just read it didn't we well we're   going to read the sensor because the idea is that  our arduino is constantly checking the sensor it's   always on the lookout hey did the sensor change  did it did it change again is something different   so every time through this loop which is running  rapidly the arduino is on the lookout for a change   and when it sees a change this switch case can  react differently so i'll go ahead and upload this   and i'm going to open up that serial monitor  window and you'll see it's low and the sensor i   have attached i actually just have a potentiometer  attached a potentiometer is like a dial think of   like on a amplifier or in an old school radio you  know as you turn that dial to change the station   so i'm just gonna sli slowly change this  and you can see as i change that the value   is changing sensor reading is changing because  the value at sensor pin is changing and as i   adjust it lower it's doing that as well so you can  see again how this control structure is helping us   adjust what happens in the sketch itself all  right we're going to look at one final sketch   and that's going to cover some of those other  super important arduino functions so let's go to   file examples button so now this is a sketch  that is going to check for a button press so   this circuit looks something like this we're going  to have an led attached through a 220 ohm resistor   to pin 9 the other side going to ground but then  we're adding in a button one side of the button is   connected to pin two the other side of the button  is connected to ground so you can forget about the   potentiometer just look at the led and the button  here so what we want this code to do is look at   that button and we want to change how the led is  reacting based on the what the button is doing   so in this case when we press the button the led  is going to turn off and when we're not pressing   the button the led is going to be turned on all  right so what do we have at the top we've got some   variables should be familiar with these by now  we've got button pin we set that equal to two   and led pin we set that equal to nine  again that's where we've connected our   hardware right the button at pin 2 and the led  at pin 9. these are set as integers they could   be bytes but it's okay to have them integers and  then they're qualified as constants they're not   going to change so that's why they're made as  constants but then we have a variable called an   integer called button state and it's set equal to  zero now the button can either be on or off so we   could have set this equal to a boolean but setting  it equal to an integer is fine too then we get to   our setup function and we're using the pin mode  again so we can use the pin mode function to   set those pins as outputs like we're doing  with the led we're setting it as an output   or we can set a pin as an input so we could just  do input like this but we can also set it to an   input pull up now i won't exactly get into what  pull-up resistors are and all that stuff right now   but basically what it's saying is hey we're going  to set this pin to a high state and if you want it   to change you need to pull it to a low state but  for all intents and purposes we're saying hey we   want that button pin that pin 2 to be an input and  if we wanted we could just do input but in this   case we're just going to go with input pull up all  right so in setup which only runs once we're going   to use pin mode to set one pin as an output and  one pin as an input and then inside the loop what   do we do let's see first line of code we come into  we've got our variable button state it's set equal   to zero now and we're setting it equal to this  function digital read button pin so here's another   super important arduino function digital read  we know it's a function because it's got those   parentheses right it takes a value in here and  it's a reserved function name it changes to the   color orange and what digital reads going to do is  it is going to read the voltage at that button pin   and it's going to check whether the voltage is  high or whether the voltage is low now in our   case when we are not pressing this button since  we made this an input pull up pin 2 will read   high but when we are pressing that button what  we're doing is we're introducing ground voltage   and so pin 2 is actually going to read ground  voltage when we press the button so that would   be a low voltage state so when we don't press  the button this is going to be high and when we   do press the button it's going to be low high  is represented by a 1 and low is represented   by a zero so if we don't press the button  then digital read is going to return a value   what's that value gonna be if we're not pressing  the button it's gonna be a one so then button   state would be assigned the value one and then we  get to some control flow we've got our friendly if   statement and we look at this condition in this  control flow and it's saying hey button state   equal equal high hey what is this isn't that an  assignment operator well notice that it's an equal   equal this is actually checking for equality so  it wants to know hey is button state equal to high   well we said it was right because digital read it  was reading button pin if we're not pressing the   button it would be a one it would be high right so  this is true and if that's true we would run the   code inside the if statement and in this case we  come to another super important arduino function   digital write so we had digital read a second  ago that's for reading digital inputs either on   or off inputs and digital write is for creating  an output on those digital pins either a high   voltage or a low voltage so digital right it's  going to take two values first it needs to know   what pin to apply the voltage at and then either a  high voltage or a low voltage so in this case the   voltage is going to be high we want that led to  be on if we are not pressing the button so now we   see another part of this control flow it's called  an else so notice that the else comes right after   the end of this if statement and it's got its own  curly braces and what this else is doing is saying   hey if the if statement is false so if this is not  true go ahead and do this other thing so if this   else do this right so if we're not pressing the  button then we're going to write the voltage to   led pin low so what this control flow is going to  allow us to do is check the current button state   and then whether or not it's pressed it's going  to do one thing or another thing now we could make   this an else if and if we add the if there we had  another if we could add another condition in here   like maybe we had two buttons and we said if  the other button is high then do this won't   do that now but just wanna let you know that  that's something that you can do all right i   know that was a lot we talked about how every  arduino program is laid out with setup and loop   we talked about variables how they're buckets for  storing information how you can declare them and   initialize them in the different data types there  are we talked about a couple control structures   namely the if statement the if else and also the  switch case statement now there's a lot of other   control structures that are really useful for  example a for loop and a while loop we won't get   into those now and then throughout this whole  conversation we've been talking about the most   important arduino specific functions the pin mode  function digital write digital read analog write   analog read and then the serial  library function serial begin   and serial print and serial print line and then  finally the delay function now i know that's a lot   to take in but really that just laid most of it  out right there for you it's really these basics   that allow you to do tons of stuff so all the  stuff we talked about here is core critical stuff   that you need to kind of get into your brain and  practice play around with go into those example   sketches see if you can see any of this stuff  see if you can follow some of the control flow   now we've only scratched the surface though it's  going to get really exciting because we're going   to start talking about arduino libraries and  what arduino libraries are going to let you do   is start using all different types of hardware by  simply using other people's code so what exactly   is an arduino library it's not like you know  a place with a bunch of books about arduino   right you're right it's not that when you hear  the term arduino library what it's referring to   is code that someone or some group of people  have written and they've packaged it up to work   on a specific thing so an arduino library is  code that's developed for a specific purpose   and is packaged in a way that allows you to access  all of the functionality without necessarily   having to understand all the dirty details because  anytime you're writing code and learning about   new stuff and figuring things out there's a lot  of complexity and what an arduino library does   is it abstracts away some of that complexity by  giving us simpler ways to access the functionality   so let me give you an example let's say you sit  in your car and you want to start it right maybe   you have a key start or a button start or maybe i  don't know maybe there's like clapper start cars i   don't know whatever anyway all you got to do is  something really simple right but what actually   takes place inside the car is rather complex  it's got a starter in there or maybe i guess   if you have an electric car maybe there isn't a  starter but you get the idea all types of things   are happening by you simply turning a key pressing  a button whatever right you don't need to know   the details of all that all you have to do is turn  the key so an arduino library is sort of like that   there's a person or several people who have  worked together to write code to control some   type of hardware or do some type of calculation  for example controlling a stepper motor or a   servo motor or maybe lighting up some neopixel  leds so these people have put in the blood sweat   and tears to make this code work and what you're  able to do is just use the functions or part of   the code that they've written in order to invoke  all of the stuff that is going on in their library   and what's amazing is you can get these arduino  libraries for completely free almost all of them   are open source they're just being shared out  there just about any piece of hardware out there   that you want to control there's probably going  to be a library that's already been written to   help you control it and i want to try to drive  the point home that this is absolutely amazing   you're basically being handed all these tools  that you can start using people are just like   hey here use this tool hey use this tool it's  like i don't know to me it's really exciting   now i'm not saying you're going to just blindly  use any library it's a good idea to have an idea   of kind of some of the inner workings but when  you're just getting started and you really have no   idea how the coding works at all it's fantastic to  be able to just use these libraries and bam there   you're going you're like off to a running start so  hands down access to arduino libraries is stinking   amazing so now i am going to show you how  to install an arduino library it's super   simple so first here's a quick bonus when  you download the arduino ide they actually   already include some really handy libraries  so you can just go to the arduino libraries   from sketch include library and see the list  here now if you want to install a library it's   pretty simple there's a couple ways to do it so  you can either go up to sketch include library   and then go to manage libraries or you can go to  tools manage libraries and it's going to open up   the library manager before i get to the library  manager though what i'll usually do is search for   a library on the internet so i'll google something  like arduino servomotor library or arduino   accelerometer library i'll find a library on  google i'll see what the name is and who wrote it   and then i'll search for it in the library  manager so let's just run through that real quick all right several different listings here i'm just  going to click this one by electronic cats kind of   a cool name so the mpu 6050 by electronic cats so  this looks like it's a specific accelerometer so   if i have this specific accelerometer you know  i already have the hardware then i would have   searched for this i probably would have gotten to  this page if i haven't purchased an accelerometer   yet then maybe this is one of the accelerometers  i would consider buying because i know   there's a library that i can use to control it  so now all i'm going to do is just grab this   part right here mpu6050 i know it's by electronic  cats now i'm going to go back to the ide paste it   right in there and now this is filtering and i'm  coming down here and then look at this see a bunch   of them come up there's several different ones for  this mpu6050 but this one is by electronic cats   so i know this is the one i want i'll go ahead  and click install that easy and now it tells me   it's installed so what actually is happening  when you click install well what's happening   is the arduino ide is going out to the internet  it is grabbing all the code files and it is saving   them into the libraries folder in your arduino  folder so let me show you exactly where that is so   i'm going to go ahead and open up my documents so  here i have documents you know my documents this   is the arduino folder right and inside the arduino  folder you have a folder called libraries and this   is where that folder is going to get saved all  that code is going to get saved so let's look   for it oh there it is the mpu6050 and here is all  that code right there it just gets saved into this   libraries folder if you wanted to you could just  download this library and paste it right inside   this libraries folder but that's what it needs  to go inside this libraries folder okay so that   is how you install an arduino library let's go  ahead and do the same thing in arduino ide 2.0 so here i am in arduino ide 2.0 and guess  what i got to do i can go up to tools manage   libraries and instead of opening up a box over  here a new window it's just going to show the   libraries right here so this is the same  thing you're going to search and filter   and then a shortcut to get here instead of  going to tools is just clicking this little   these uh shelf book of libraries right see it just  pops up like that and then you would do the same   thing you could click install so it's really  pretty much the same thing okay so that is how   you install an arduino library all right what i'm  about to show you isn't some type of secret but i   have met so many people who don't realize that  this actually exists alright so here's the deal   when you install a new library a very common  thing that comes with the library are example   programs that demonstrate how to use the library  and this is how you get to them alright so i'm   gonna go to file examples and now i'm gonna scroll  down and this is examples from custom libraries   so these are libraries that i've installed  right that we just did like we showed there   and i'm going to come down to that mpu6050 i'm  going to come over here and i can see that there's   a bunch of different example files i'm just  going to go ahead and go to this mpu6050 raw   and what this sketch does is it is a working  sketch on how to use this accelerometer sometimes   they'll have comments in here to help you explain  different lines of code but they're going to give   you some basic examples of actually how to use  the accelerometer now look at this this is great   it says use the code below to change the excel  gyro offset values so they're giving you a bunch   of code to kind of play around with to adjust the  accelerometer so you can literally take this code   upload it to your arduino and just play around  like hey how can i make this thing work how can   i make this thing adjust it gives you a known  thing to kind of start with and many times in   these examples they're going to give you the types  of programs that you'd be looking for so anytime   you get a new library first thing you should do  first thing i always do is i go to those examples   and i just start reading through the examples and  see if i can make heads or tails of what's going   on and i will play with the example sketch before  i ever start trying to write my own code from that   library all right so that is the quickest  way to learn how to use an arduino library   all right now what i want to do is i want to  show you two examples of a library in action   so check this out here we are i'm going to go to  file examples and i'm going to come down to the   servo library and i'm going to come over to knob  now the servo library is going to help us control   a servo motor and we're going to control it using  a potentiometer so potentiometer is like a dial   like you think of an amplifier you know you'd  like turn the volume up turn the volume down   or like old-school radio dial right and so as  we turn the potentiometer it is going to move   this servo motor and this is what the circuit  diagram would look like so here's our servomotor   it's connected to power and ground on this  breadboard which is then connected to the arduino   and then we have a potentiometer the middle pin is  connected to pin a0 and then we've got the outside   pins the potentiometer one hook to ground and  one hook to power so i do want to mention servos   can really draw a lot of current especially if  you have a load on the servo so like let's say   you're trying to move some amount of weight even  if it's somewhat small that current requirement   can surge and the voltage regulator on the arduino  can only provide so much current so generally   it's a good idea to use a separate power supply to  actually power the servo but you control the servo   with the arduino again lots of details in this  stuff i won't get into it but since we've got   no load on our servo we'll be just fine so if we  look at this sketch we are including notice at the   top here we say include servo.h this allows us  to use all that code in the servo library here   this kind of looks like we're creating a variable  right what we're actually doing here is creating   an object we're using a class that's part of this  servo library the type is servo and the name we're   giving it is my servo then we've got some other  variables here this is for our potentiometer pin   hooked in at pin a0 and then there's a variable to  hold the value that gets red from a0 now in setup   we're going to do something that runs once and  so here we're calling the attach function that's   provided by the servo library and we're going to  attach pin 9. that's where we've got the servo   signal line plugged in start some serial  communication here then we get into the loop and   notice what we're doing so we've got that variable  val so first we're using analog read at pin a0   right so if you'll recall that's using the analog  to digital converter it's going to take whatever   position we have that potentiometer at it's going  to take it and store it in this variable val and   then down here we're going to take that value and  we're going to map it to a new range from 0 to 180   because most servos you use they can move 180  degrees in either direction and then we're going   to use this function myservo dot right and put the  value in and what this is going to do is tell the   servo what position to move it so if val is a zero  it's going to move to the zeroth degree if val is   180 it's going to move to 180 degrees and anywhere  in there so if we go ahead and upload this code   now as i move the potentiometer it moves the  servo motor it's pretty cool and it's just   amazing how quick i was able to get that up  and running so let's look at another example   i don't know if you have heard about individually  addressable leds a common name is called neopixels   but they come in these strips and they're super  cool so one library that's used with those is the   fast led library so i'm just going to come into  fast led and i'm going to check out this cylon   now notice this example in the library it's giving  me all types of information about what i need to   actually hook up now it might take me a bit of  time to kind of figure out exactly what this code   is doing but at least i have a starting place to  work with all i have to do is make the connections   so the strip i have has 12 leds i'll make the  connections as appropriate click upload and now   i've got this cool effect on my led strip that's  pretty awesome all right well i hope you are as   pumped as i am about using arduino libraries like  i said they open up so much opportunity for you   as a new programmer because you can lean into  the expertise of all these developers all over   the world i'm going to make a claim here maybe  i'm wrong but i would say arduino hands down   has the most libraries available for all different  types of hardware out there it's just amazing   now if you have any questions about this please  just ask the question in the comments i'm going   to do my very best to answer all the questions  also while you're down there if you could like   our video and if you haven't yet subscribed  to our channel it doesn't cost you anything   but a click but it really helps us bring you great  content like this arduino programming workshop hey   if you made it this far and you hear me talking  right now congratulations i'm hoping that you just   learned a ton of stuff and it tells me if again  if you're this far into it you really want to   try to learn this arduino stuff now if you enjoyed  this workshop you feel like you're kind of getting   ahead a little bit then i really think you would  enjoy the training that we offer at programming   electronics academy now our flagship training is  called the arduino course for absolute beginners   and it lays out module by module a clear and  concise guide for learning the ins and outs   of programming with arduino you're going to  start at the very beginning getting familiar   with the arduino ecosystem and the fundamentals of  programming then you'll dive into programming for   inputs and outputs you'll learn coding structure  to help build logic into your programs and you'll   do a deep dive into coding libraries and how to  find and use the best ones for your application   we'll cover using arrays and writing your  own functions and finally we'll cover using   interrupts and timers to make your code react to  inputs exactly when you need them by the end of   this training course you're going to have the  programming knowledge to start writing code to   control your own projects you'll understand how to  lay out an arduino program the specific functions   you'll need for reading inputs and creating  outputs and you're going to know how to structure   your program so that it flows like you wanted  to now here's what's crazy this flagship course   is only one of the courses that comes as part of  our program we have courses that cover connecting   your project to the internet on how to power your  project course on basic electronics on using lcd   displays on using audio boards for making noise  on using servo motors and more and we keep adding   concise high quality training programs and here's  probably the best part of this program if you ever   get stuck or confused on a lesson in our training  you can simply ask for help in our private forum   and get a pleasant response thanks again to  altium for sponsoring this training check out   the description to get a free trial of the super  powerful altium 365. if you want to learn more   about this training program just click the link  in the description to get started thanks a lot   again if you want to check out that program just  click the link in description have a great one bye