Arduino Tutorial 34: Simplest Way to Use a Pushbutton Switch

[@apoorvaditya9010]

Paul, your enthusiasm for electronics has made me a fan of you

[@SamFromSpaceOfficial]

Mr. Paul, your tutorials have really helped me to understand and learn Arduino. Your teaching style is like no other. Please keep posting Arduino tutorials!

[@elloco99999]

I always prefer to have the value read "0" when the button is not pressed and "1" when it is pressed so I tried connecting the button to 5V and pin 2 and to write "LOW" to pin 1 to see if that would work as a pull down resistor. And it did :) Thanks for this neat trick Paul!

[@MarvPerk3]

Halfway Home... lesson 34 of 68! Loving learning new tech at my age, 70. Loving coding again, which I did a bunch before I retired. I still don't quite understand how a pull up resistor is introduced by setting an input pin to HIGH... but I'll go back and watch again. That confused me in the last lesson, too, no fault of yours.

[@nobleforks8911]

Its the same idea as putting the resistor to +5VDC, when the button is pushed it creates a path to ground so pulls the pin low by creating a low impendence circuit to ground.

[@jhnmur]

@@nobleforks8911 Can also use command INPUT_PULLUP

[@aynursunagatullin7029]

Thank you Mr. McWorther, I love this, now it's much easier for me to create pull up switches, also I decided to do a bit of neat formatting, so I added two if functions to say wether my button is on or off in the serial monitor. Here is the code. int buttonPin=12; int buttonVal; int dt =100; void setup() { // put your setup code here, to run once: Serial.begin(9600); pinMode(buttonPin,INPUT); digitalWrite(buttonPin,HIGH); } void loop() { // put your main code here, to run repeatedly: buttonVal=digitalRead(buttonPin); Serial.print("Your button is"); if(buttonVal==1){ Serial.println(" off"); } if(buttonVal==0){ Serial.println(" on"); } delay(dt); }

[@malcolmsnow4799]

BOSC O - I've watched them all - can't wait till you get into interrupts and multitasking. Thanks Mal

[@thelocal911]

You made me learn pull up and pull down resisters knowing full well, all along, that this existed!?!? Well played, sir.

[@autocrosser10]

Watched this one prior to lesson 32. I think it helped to do this before you taught us how to use the joystick. Half way done with the new lessons and I'm still here watching to the end and doing all the math. Your doing something right!

[@mikeroerig2499]

I just finished tutorial 34. I am writing the code for your projects before watching you do it. Thanks for doing these videos. I will utilize an Arduino to control an arcade shooting gallery that was made in 1969. When manufactured, the game was controlled by a custom 8 track tape player. I have been unable to get the tape player to function reliably so I will have an Arduino take over the game control. This shooting gallery was been rescued from the trash and completely restored. An Arduino will allow me to finish this restoration. Your tutorials enable this to happen.

[@alanfowler3069]

BOSCO, Hi Paul, this is the second time I've followed these tutorials and got to this point. First time stopped due to work commitments, this time determined to see it through until the end. Very new to coding and electronics, but learning all the time. Thanks

[@georgeshaiffer2246]

Thanks, You used this with brief explanation in previous, without mentioning the internal pull up resistor. Much clearer now as to what is going on.

[@RockOn611]

This tutorial is very helpful for better understanding the 33rd tutorial. Thank you for explaining briefly sir.

[@jeffbowyer4576]

I've played with Arduino for ~1 year. This video is THE MOST IMPORTANT lesson that I've learned. YES, external pull-up resistors are OLD SCHOOL!!! (yet everyone continues to use them)

[@daveharkin4731]

thank you Paul for your time and effort you put into these videos, I really appreciate them. Please keep them coming. When you get the time could you do a video about interrupts and switch, case programming. you seem to be the only person on KZbin I can follow and understand, you teach in an excellent way.

[@gilmertugahan]

The new IDE already has an INPUT_PULLUP feature. I think the IDE you were using doesn't support that. But, it's good to know that it can still work by doing a digitalWrite. It is useful for me because most Arduino micros I've bought doesn't support the new IDE. Thanks so much Sir.

[@andrewwilksch]

A clever man. I'm learning as we go. Some is over my head but I'm getting there. Andy.

[@Hino_55]

Thank you for this tip Sir Paul! I have to agree with the earlier comments, that using the parameter INPUT_PULLUP seems more natural and intuitive as it eliminates the need to write digitalWrite inside the void setup().

[@mayankshigaonker7725]

As far as I know instead of using 2 lines of code for making that pull-up resistor you can use 1 line of coffee that is pinMode(buttonPin, INPUT_PULLUP);

[@mightythimble4942]

No secret word?? Have you gone MAD?? lol this video filled in a very important piece of the puzzle for a project I've been building. Many thanx, Paul! Would love to see a tutorial on shift registers with the kind of detail you put into videos. It's been an real treat to keep up with these.

[@rupert310]

tried it first on my own and got horrible feedback. Your method worked great. good tip.

[@billlaird7332]

I have become addicted to this series and particularly your teaching style. I understand that you went through the whole push button using pull up and pull down resistors in lesson 33 so that we understood the theory. I really like how you integrate the hardware, software, and physics. I am already looking forward to your raspberry pi series after I finish the arduino.

[@paulmcwhorter]

Wonderful!

[@eparizi]

am I missing something in lesson 33 or you meant lesson 27? I don't see anything about buttons in 33. And I still don't understand why this method works. so far this has been the lesson I struggled most with.

[@berryblades]

I watched this video about 5 times, love it, please never stop Paul!

[@michaelw24401]

Hardware pull-up or pull-down resistors, this method and INPUT_PULLUP; we have options. I like the idea of using the Arduino internal pull-up because of it's simplicity but I wonder in what applications hard-wired PU resistors may be to our advantage.

[@nobleforks8911]

Less work for the MCU, INPUT_PULLUP or setting the same pin as INPUT and HIGH at the same time utilizes the limited power output of the board. This is the reason to use resistors; resistors just get rid of stray current(could be generated by as simple as your fingers close to the button or stray EMF in the air) to be grounded.

[@muhammadrafiqulislamkhan6994]

Your every video is very important to me to learn Arduino programming. Thank you.

[@peterleitner2383]

that answers my question from one of the previous videos. Thanks

[@TheKverbeeck]

That saves some Dupont wires and resistor, very cool indead, we used this trick already for the Joystick push button if i am not mistaking 😀😀😀😀

[@richardbritain7435]

Nice little corner cutting method. Thanks.

[@kuravani1963]

Paul, Thanks for a nice simple understandable tutorial.....

[@gilnasty82]

So much easier this way! And makes complete sense how it works now!! Thanks Paul!!

[@wendygrant2735]

Thanks for this tip to use the Pushbutton Switch.

[@naturalfrequencys4283]

Paul, This trick helps me greatly in my project. You are amazing...

[@erikburman530]

I love it that you have to fiddle with the PCB microswitch the same why I do. It seems that they only work marginally well with breadboards.

[@andrebedard1816]

You did that in lesson 32 and I was wondering about doing a digitalWrite to an INPUT device. Now I know why. Thanks

[@samwain8713]

Bosco very cool method of checking if people are getting the most out of your videos

[@NothingToShoutAbout]

I’m so grateful for you. You are an amazing teacher.

[@rexaustin2885]

i was going nuts trying to understand why this was done during the joystick code. now it makes sense.

[@alirezabayat6388]

hey mr. McWhorter, glad you're still reading comments and before anything i want to thank you for this series, you're an excellent teacher. i have ran into a problem with this technique, if i don't use a resistor and don't do the "original" way of wiring a button, the button value goes up and down by itself and ignores my input. same thing happened with tilt sensor which i fixed it by using a pull up/down resistor. do you have any idea what's going on? i guess it's worth mentioning that i'm using a no-name brand UNO R3, which seems to be working fine everywhere else!

[@yasins8713]

i cant believe that this actually works. thx for showing me this trick and love the tutorials i have learned a lot from you. thank you

[@practical_precision_shooters]

great tip Paul, really simplifies the use of buttons!

[@paulmcwhorter]

Glad you liked it

[@velingaming7196]

Epic video Paul! Been testing it out by making a program to let program be run once with 1 click. Having a blast with it! Thanks for your inspiration!!

[@paulmcwhorter]

Fantastic!

[@JonathanDeWitt1988]

Paul, Thank you for showing us this trick. This was a great video. I just had two quick follow-up questions. 1) Why the heck do we even use pull-up resistors at all? Is it that this trick just isn't known or is it that there are stability issues. Because I noticed you mentioned theoretically that it was stable. 2) Is the internal pull-up resistor internal to the ATMega328P chip or internal to the surrounding circuitry on the Arduino board? I ask because I use the standalone ATMega328P circuitry in a project with a push-button wired up to it. Being able to eliminate a component/installation step with a few lines of code would be great. Granted after watching your series I am considering replacing the pushbutton with a potentiometer to give me finer control on my program.

[@takiskard2414]

Boom, I also programmed internal LED (pin 13) as an indicator to show switch status (saving having to wire external LED/resistor). Works a treat :-)

[@jonwebb5395]

I am in the process of learning how to use Arduino board and love these tutorials. However, while watching this tutorial and reading through the Arduino instructions, it appears there may be a simpler way to write this but I am not sure if it applies here. Instead of instantiating the pinMode as INPUT, can we instead instantiate it as INPUT_PULLUP and then get rid of the need for the digitalWrite(buttonPin, HIGH) line?

[@lorisrobots]

Yes - that is what I am doing too.

[@Musicalcode313]

thanks for the insight! less is more =)

[@philnewman1110]

I aim getting hooked on these tutorials Paul, really enjoying the series, thank you!

[@fahimabrar8141]

Just realized I am half way through!

[@paulrockwell9914]

Paul, why did you choose to use : pinMode(buttonPin, INPUT); digitalWrite(buttonPin, HIGH); as opposed to. pinMode(buttonPin, INPUT_PULLUP); to set the internal pull-up resistors? (yes, both do the same thing as others have noticed...)

[@alanfairclough8879]

Got it right first time around. Even remembered to set up the serial begin. I feel smarter than shit!

[@wallymurray620]

Short but informative lesson. Thanks again Paul.

[@abdullahmuslim280]

This Tutorial is short but informative.

[@markfuentes3666]

Great way to use internal components. Thank a again Paul.

[@Azzys007]

Hi Paul, I've been watching a few tutorials to help me understand this concept better and I thought I did until I watched this... Does your method without any resistor not short out the supply with ground?

[@mikemanny1533]

Wow...this is a great hack for simplifying the pull up resistor switch scenario. That's three ways I've learnt now...(1) Using the actual external resistor set up...(2) Using this excellent method...........and (3) using the pinMode(buttonPin,INPUT_PULLUP) method. Like the old saying goes..."There's more than one way to skin a cat." I would think that it's real handy to know all three...and there are probably others out there too; I'm sure that given a certain situation, at a more advanced level, each method could come in useful, having that little advantage over the other in that particular application. Thanks again, Paul. Stay safe, mate....and best wishes and regards to yourself and family. Cheers....Grumpy LImey.

[@abdallahkhamis881]

brilliant !

[@derekarruda882]

Can you use internal resistor as a pull-down?

[@sammysam1503]

NO SECRET WORD? Its ok Paul, your videos are amazing! Thanks for this tip, it makes push buttons so much easier to make!

[@wayneandrews1738]

I believe the Arduino site someone mentioned that an internal app. 30k resistance is used. This should prevent arcing switch contacts. Probably the shortest lesson.

[@abhik1493]

Hello Sir, I really love your lessons but would love it and wish we could do advanced stuff like in your first tutorial. I am sure many people would like this as well.

[@captainprototype187]

Dont you want the button always to read a 1 when it is pressed?

[@olegvelichko1659]

ButtPin... BWAHAHAHAHA!!! Got a good giggle out of that one! Hey, doing a whole video in one shot takes skill! Thank you, sir, for the great content. When’s my next fix coming? This was too little of a dose!

[@captaineverythingfun52]

I was literally thinking the same thing LOL

[@angusclarke8592]

Paul, Where can I get the basic instruction of what the commands mean & the syntax that should be used when compiling a sketch. I'm always confused as to how you just know in what sequence to write your code without breaking stride. I'm always struggling to understand, what tells what to do what & why and what will the outcome of commands be? ?

[@thebrewsterblock]

Another great video. Now I am a bit confused. I have used both this: "pinMode(buttonPin,INPUT);" as per your code or this: "pinMode(buttonPin,INPUT_PULLUP);" both with "digitalWrite(buttonPin,HIGH);". They both work. Don't know the syntax well enough. Is ",INPUT_PULLUP" assumed by just ",'INPUT"?

[@DesmondStanulis]

This video was extremely helpful!

[@paulmcwhorter]

Glad it was helpful!

[@riskitall7421]

Quick question Paul: I was under the assumption that straight volts to a component would make it smoke. Is this only LED's? Why is our button safe without a resistor? Thanks in advance!

[@MustafaKaya-vd6pd]

INPUT mode activates the pull up resistor that is inside the arduino itself ( 20K ohm ). When you write HIGH to it, and if the button is not pressed, you will be reading 1. When the button is pressed the circuit will be complete and current will be flowing to the ground so the presence of resistor will make the current so low that you will be reading 0.

[@Pwyllugh]

@@MustafaKaya-vd6pd Thank you for that explanation! I was wondering about this as well

[@hawrazahmad9411]

thanks paul I'm so excited when Watch this lesson.

[@aeroakram]

Hi Paul, I was just wondering if this does not somehow create a short (i.e. the HIGH signal pin directly connected to GND)? Or does it not create a short because the signal pin is defined as an input to begin with and "HIGH" is just a superficial state?

[@favesongslist]

Internally it uses a safe high value resistor to pull it up to VCC, so no need to worry. (around 100k ohms) pinMode(pinNum,INPUT_PULLUP);

[@richardfeist9340]

Once again, another great lesson! Simple but very useful. Thank You!!

[@paulmcwhorter]

Thanks again!

[@TheSgrizli]

Am I the only one who binge watches these? Day 3 and I'm already at 34...

[@rushipadhiyar2615]

I am with you bro, day 4 and already at 34.

[@WhirlwindCK]

Indeed; playback speed at 2x, and ready to blaze all the way through in a week.

[@zackhenderson2392]

@@WhirlwindCK 1.5 here, so I can write notes ^.^ Can't wait til I know it all and can start on my project for real

[@klaushansen5779]

Day 3? can you say 2. ups, even tho ive started late yesterday.

[@TheBoothParadigm]

Did you know you can do: PinMode(buttonPin,INPUT_PULLUP); This way you don’t need to do an extra line of digitalWrite(buttonPin, HIGH); in the void setup. Can also do pulldown.

[@billglass5160]

Paul, you anticipated my question about asking why you could do this in the previous videos for the joystick switch. If I correctly understand, the pin2 output driver impedence replaces the 330 Ohm pullup resistor? No reliablity problems in shorting the IC outputs? Thanx.

[@handywijaya11]

Hi Paul,good job. I put a marker at the end of program that on and off the internal led. Sometime my servo get hang while running for a while,and so that the internal led not blink anymore.Any suggest?

[@pokerface68]

No WORD? Please, say hi to Bosco and pet Indigo for me anyway. This was a short and clear lesson, I feel like things are really starting to click now. Thank you once again!

[@thomasstenger7951]

Paul, your videos are absolutely amazing! Thank you sooo much, I have learned gobs. Have you ever made a video where a single button has multiple possible outputs based on how many times the button has been pressed? I am in need of a circuit that reads how many times a single button has been pressed (up to 3 consecutive times) and based on that input performs one of three different functions. Thanks Paul!

[@Joker3985]

Once again, a wonderful/informative video!! Question, I have been playing with interrupts (both HW & SW) and wonder if this simple way would work with that - so that when you press the button, the interrupt would trigger. Thanks!

[@ardinokirzli2189]

Thank you very much best teacher in the world .

[@ahole5407]

Great videos and all, but I'm just here to find a way to wire simple "up" and "down" buttons to scroll through different led lights on my motorcycle.

[@DanielRhoades4122]

So, when building a project, is this method better than the other method? Also, would this work with the smaller Arduinos (nano, pro mini, etc)?

[@andywylie287]

Boom!! Thanks for another great tut, Paul.

[@nexbedwars7408]

Paul I am not able to fit my switch because the curved leads which are facing each other is lengthier than my breadboard itself(columnwise)!

[@bokax1995]

Another great tutorial! Practical method.

[@paulmcwhorter]

Glad you liked it

[@mohammadalijaffal1876]

nice arduino tutorials Mr. Paul, please I need your advise in a project, if I want to make a drone using NRF24 what I need to know in the arduino software? thank you

[@ReoGizmo]

Very nice video. Is it possible to do a PULL-DOWN with just code?

[@bearpapa1606]

I'm just curious is it possible to do this the other way around like "digitalWrite(buttonPin, LOW)", will this cause a short circuit?

[@weversonbarbieri8986]

Paul, you are the best!!

[@haastrupadebayoibukun6817]

Perfect. So the switch was set to be HIGH instead of making another connection to the 5V source. It's obviously more simple and easier.

[@sparshgarg7937]

Hi Paul, I had one doubt that what am I doing wrong if I write, pinMode(buttonPin,OUTPUT); Because the results are similar..

[@Tonicwine999]

When he says this is just a quick and dirty version what are the disadvantages of doing it this way? Does it damage the circuit in some way?

[@Shalfatk01]

is there any downside of using this technique in terms of hardware problems? shorting circuit or anything like that ?

[@pouyanrouzbahani5419]

5:58 We say pull_up next to the INPUT or this. Are there any differences?

[@alanpond7486]

BOSCO! Love your tutorials! I recently discovered the 'map' function -might have been useful in this application? :) Ciao!

[@nikkitezla3367]

Made to Bosco and I am also mounting a laser that will be turn on with the joystick.

[@pfleischman2471]

Bosco - Awesome series thank you very much!!

[@aaronmilliman7685]

Great video, maybe Bosco should sell coffee and call it Indigo. :)

[@ryandyc]

How does the Arduino Serial.x library work? How does it do the UART and printing?

[@easymac79]

This will be very helpful. Is there any downside to this? Does it cause the arduino to heat up more? I presume there is little current carrying capacity, it's just to signal an operation, if you want current, trigger a relay. I guess I wonder why anyone would bother with a seperate resistor if you can write a line of code. I did learn, this evening, why the microswitches always have four leads. I've conducted repairs on small electronics in the past, such as a computer mouse, and wondered why there were four pins on a switch; I already figured out the three pin switches that only use two because it's bulk manufacturing, just use the N/O pins. I need to go back and watch episode/lesson 27. But I think this must* be why the micro push buttons have the four pins, it's not double throw, it's so manufacturers and others can tie a pull up or down resistor to the switch without having to double up on a pin with solder and wire or make the board more complicated.

[@ronnieyu7514]

Hi Paul! I really enjoyed and having a lot of fun with all of your videos. I was wondering if you can make a video of connecting or integrating esp8266 12e module with arduino uno and connecting it with amazon Alexa. Many thanks and more power to you!

[@josschrijvers8782]

Even without a secret word, Thanks a lot, Obrigado!

[@gweliver]

Paul, very nice follow-up tutorial on something so simple in design, but we need to always do the "MATH", right? "Make America Think Harder", umh? Now to watch the tutorial, more possible comments to follow?

[@alexschmidt4371]

This is the first video that I watch till the end and have one thing that I am confused about. How are you connecting ground(negative) directly with pin 2 (positive)? To what I know, this should in theory cause problems, but it just works!? I am really confused what I am misunderstanding here :| Edit: Maybe I need to explain a bit. in an alternating current (AC), it you make positive and negative wires connect, you will get a serious problem and should cause things to break if not protected. I know this is Direct current (DC), but isn't it the same concept?

[@yadusolparterre]

How are you not creating a short when you press that button? VCC connects directly to GRD

[@favesongslist]

Internally it uses a safe high value resistor to pull it up to VCC, so no need to worry. (around 100k ohms)

[@jamieyz]

My question too. Thanks for the answer Timothy!!

[@rccanuck4473]

Hi Paul I have an 8 digit 7 segment display with the Max 7219 chip. I want to make it show scoring points on a pinball machine using an arduino Nano or Uno. Not sure if you have something already on one of your videos would require push buttons to change the score preferably one to change ones, another to change tens and another for one hundreds? Any help would be appreciated Maybe even a good course to do if not already Regards Pb

[@guilhermedantas3200]

I do the exact same using the D0 pin in a NodeMCU8266 and the read is 1 at the begining, if press it, it goes to 0, but then if i release the button it stays at 0, why is that?