Electronic Basics #30: Microcontroller (Arduino) Timers

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In this episode of Electronic Basics I will show you how to use the timer of a microcontroller (Arduino Uno -- ATmega328P) to not only create precisely timed events but also generate a PWM signal with variable duty cycle and frequency up to 8MHz.
Music:
2011 Lookalike by Bartlebeats
Killing Time, Kevin MacLeod (incompetech.com)

[@Geradovitch]

So different of electronics I earned in the late sixties. Have tried to keep up to date on my own. Learned how to fix digital tv's and am now interested in microprocessors .I have ordered a full arduino kit with sensors and learning Python and Linux. Plus I have been following you on You Tube for the great projects you explain. Keep up the great work, You are a good teacher.

[@vaibhavpatil9956]

I am interested in old electronics can please share what type of electronic were in 60s

[@executorarktanis2323]

That's great seeing you still learning sir please reach out to me if you require any help also btw they are called microcontroller 😊

[@pesterenan]

This is the basics? wow! And here I was thinking that I was smart by using a previousmillis(); function xD

[@nishadnadkarni7874]

Pesterenan the stuff he's doing is basically what you do when you use the atmega on its own without the arduino ide and its libraries (but with atmel's libraries), its mostly just writing data to registers and reading from them. In the video he goes kinda fast so you will find it overwhelming, but take the time to look at other videos and tutorials about the 328p's timers, its not that hard. The datasheet gives you what bits you need to set in which registers to configure the timers how you want. Obviously you need to look at tutorials and read up on them to understand them well. But once you have an idea of how to configure timers and what registers to use and a few basic modes, figuring out other modes isn't that hard and you can refer to the datasheet. You will need to look up stuff online but its not that hard. I don't know everything about the atmega 328's timers but from what I know its pretty easy. I've moved on from the atmega though.

[@SuperNesmaster]

@@nishadnadkarni7874 what other boards have you moved on to? Just curious. I'm just getting started with the arduino platform but do not know if i should start with the arduino IDE or using atmel studio.

[@shivashankar28]

@@SuperNesmaster Start with arduino IDE then move on to atmel studio

[@JaySilva88]

I didn't understand a thing, but great video! ahah

[@kuyanatnatdkrx7]

Embedded Micro controller Technical Jargon didn't make sense to me at first time I heard it. interrupts, timers etc are just a bunch of built in useful peripherals that does a particular function for a programmable logic device.This stuff is around the second layer of electronic and computer systems you'd have to study the basics of electrical and digital electronics.

[@mohamed_fawzy]

+1

[@nametag1723]

Me too!

[@baumdings1782]

I watch this for scool haha

[@chuck_norris]

feel it

[@frank4one]

I have been struggling to understand timer interupts. THIS IS THE BEST EVER! I can now control my steppers using either overflows or compare timers. THANK YOU!

[@raybright5805]

Excellent companion to your previous "Arduino Basics 102: Control Structures, Variables, Interrupts" - Love Your Work...

[@makermonkey6591]

I'm writing an arduino sketch to control a stepper while monitoring some sensors. The accelstepper library did not really cut it, for my application. Using this new timer knowledge I was able to make the hardware act exactly as I intended. HUGE THANKS for this tip. Awesome GreatScott.

[@WarrenGarabrandt]

I'm about to build a 500 Watt 30V - 42V motor controller for a project I'm working on. I had not yet looked into how to generate stable PWM signals in code without spinning the Arduino in busy waits that eat battery. You've given me some great ideas in this video, so thanks for your time and effort making this.

[@MikeysLab]

Having worked with electronics a lot in my life, I always found timers and interrupts to be kind of a dark art, especially before Arduino and when dealing solely with AVR or PIC. Thanks for addressing this :)

[@RobertMilesAI]

I feel like you would want to know this: "Mandatory" is usually only used for things that come from human rules, and usually a better word to use is "necessary". Consider "using a precise timer here is mandatory under EEC regulations for electronic products", vs "using a precise timer here is necessary if you want your alarm clock not to drift a lot over time". Like, wearing a motorcycle helmet is always necessary if you want to be safe, but in some parts of the world it is not mandatory. I normally wouldn't point that kind of thing out but your English is already pretty excellent so I thought you'd want to perfect it.

[@DatNerddSwaqq]

Robert Miles Wasn't expecting to see you here! Love your videos on Computerphile and big fan of your channel!

[@ganzsichertobi]

I also didn't know that. Thanks!

[@borisdorofeev5602]

Robert Miles I read your comment and understood that you are not nitpicking, but genuinely want to help a good KZbinr improve his English. So, I checked out your channel, noticed that you produce some excellent content, and I subscribed to you. The comment sections to videos like this are a goldmine of extraordinary KZbinrs.

[@joelsantiagovalentin2231]

There better option with timer

[@TheMegaloloful]

Thank you for this video! I made a arduino alarm clock a while ago, but because I didn't use a timer, the clock "lost" about 10 minutes every week. With this information I can finally fix the clock! Thank you!

[@edtix]

Finally! I miss in-depth videos like that. Keep going :)

[@MikeGecawicz]

I have been working on a project using LCDs and Stepper Motors for the past two weeks and this is the exact video I have been looking for; of course it comes from one of my favorite youtubers. Keep it up!

[@hybridskeeter]

This is a great video. Thanks for putting these timers into context with good examples, they make much more sense to me now!

[@ChrisMuncy]

Scott. Fantastic video. I would not have even known about this without either reading the docs or watching your video. Keep 'em coming.

[@emrekeremozyurt296]

u can feel the illumunation after watching this 50 time. It is more brighter than the edison's and I'm understanding them now. I loved it!

[@Bartong666]

Great video! These more advanced videos are great since the amount of videos on how to blink leds is so high and no one really goes that much into advanced arduino / ucontroller functions. Keep at it!

[@insightfool]

SUCH a good explanation of how to use Arduino style interrupts. You're officially AWESOME.

[@ryanelliott4092]

This is perfect! I have an exam on this today! Thanks for the review Great Scott!

[@andrewwatts1997]

How did the exam go ?

[@zetaconvex1987]

Thanks for that, very informative. I was looking to create a variable duty cycle at a fixed frequency, and figured I wanted fast PWM mode. Your tutorial helped me put a few things in place.

[@klausnielsen1537]

Thank you for doing these videos. I keep coming back and watching and now I even bought a ton of arduino stuff to have a go at some simple stuff. Totally subscribed!

[@riassenpai1590]

Hello Scott! Remember the clap circuit project? I build it from the first time and put it under my desk and plugged in my pc I enjoy it so much when i come home with one clap I turn on my pc!Greetings from my electronics teacher I showed some your projects to him and he sad:You can learn so much from him.

[@mrjohhhnnnyyy5797]

Well done, this video has cleared a lot of the confusion I had thinking about timers. Now I know how CTC mode works, thanks for informative video!

[@SuperFlyCH]

I have so much still to learn, sigh... This is one of those videos where I need to do some research and then come back to to watch the video again to get a much better understanding. Thanks for challenging me with your great videos.

[@kai7474]

This cleared up a lot of how to understand the timers & documentation about them for me. I was just getting to the point in some projects where I need them too!

[@binaryme335]

Great video. Some was little over my head, but if I watch things I already know, I'm not gaining​ anything. Thanks again for another excellent video.

[@RinksRides]

It is a great video. AVR timers even after explanation are still mysterious and confusing because of how they can interconnect. Respect on a next level! PWM to 8MHz?! Awesome!

[@prestonmatheny9756]

Great video! I really like how you get straight to the point, and pack in as much info as possible. Lengthy videos aren't as entertaining, and even if I have to watch this one a couple times to really get it, I would much rather prefer a shorter video than a longer video. Keep up the good work!

[@greatscottlab]

I think the same way :-) Thanks for the feedback.

[@NorbertHarrer]

Great tutorial. I have used timers on the Arduino before. But only through libraries. That was a great overview on how that works under the hood.

[@k1ckcyph3r16]

Oh I see what you did there...this is just a guide, but I find it very usefull because you managed to put all the information in 9 minutes so we can see the video search for the information to complement it ans continue watching. I guess that's not the format everybody likes, but I find it very interesting because it "forces" me to do more research and learn more than if you just give me the recipe, but that's just my opinion. Thanks for the video, nice job.

[@TheJay6621]

A step inside the arduino functions. Lot of thanks for such detailed explanation. No body cares to explain these basic stuffs only you are the saviour for beginners as well as advance users. as always Love from India. thank you for your time and efforts. keep up the good work.

[@greatscottlab]

Thanks mate :-)

[@shedactivist]

Great video as always. I didn't realise just how capable the Arduino was, but please forgive me when I just buy a RTC module for my next project.

[@stevenlittle2384]

Thank you so much, for helping me tackle this daunting topic.

[@erfanelmtalab3426]

I had problems learning the timer counter , but this video helped me enough ... Thank you sir

[@simoncroatia]

You are a very smart man and although I don't understand everything I still enjoy your videos. Thank you.

[@ix8inside891]

best Explanation to that topic I've ever heard

[@moustafa19997]

This is certainly the best kind of videos you make

[@drkastenbrot]

Im prettty sure theres many libraries available for this threading/timing approach. Very informative, I didnt know much about this. Thanks.

[@HannesMrg]

You have the perfect timing, always if I finish a project you explain exactly that in a video and it's really easy to understand the little things I didn't know already :) Also keep up the great work, I'm always really happy when the "New Video" notification pops up.

[@greatscottlab]

Thanks for the feedback :-) I will try to keep it up.

[@JoaoSilva-jr9ez]

does it happen to you too? thought it was only me ;D

[@thepixelshock]

Same here, just as I finished my audio amplifier project to drive some speakers from an old radio, Scott uploaded a tutorial about that.

[@Dogeek]

can you link the datasheets of the components you use in the video description, please ?

[@yusy4501]

An advanced topic but u make it so easy to understand. Thank u.

[@luizz1997]

Holy cow... that is another one of your videos i'm gonna need repeat a lot of times to understand

[@MinecraftM0b]

Hey, the drift off of the millis() function is caused by the Serial.println which takes some clock cycles (depends on baud rate ofc) - the timer is precise in this situation

[@MD-vs9ff]

delta I think that's the point he was making. Delay causes drift because the other code takes some time to execute, so your loop time is delay time + code time.

[@jort93z]

i use an RTC for my clock project i did with the arduino(binary and lcd clock). its the DS3231(M) and its very precise and really cheap(the whole board is literally $1 on ebay). it makes a whole lot of things a whole lot easier. and it has a battery backup. And the arduino itself drifts off a lot faster than an RTC.

[@brianhackit7900]

hey dude. just wanted to say thanks for all the vids. when i started my degree 2 years ago i found your channel. its been a great resource and ur perfect as far a host. you get all the info across well and you provide schematics and downloads and everything. so i just wanted to say tx. would've msgd you but couldve find that on this channel. thanks for providing such an incredible FREE resource for education man.

[@greatscottlab]

No problem :-)

[@Tarbard]

Great explanation as always, I like the way you present.

[@soxxks]

Amazing video. This video with Arduino documentation go perfect together. Thank you!

[@remowo_]

thank you for the analysis...This topic has always been fuzzy for me even when reading the datasheet...

[@Jay0neDE]

I can't tell you how helpful this video is. thanks!

[@nihaludeenkaisome2796]

Superb explanation about the uses of timer great scott ! Thank you for this video, it helps me lot.

[@williefleete]

been driving a large matrix of LEDs from an LED sign I reverse engineered. Using the timer helps to keep the display showing something and still execute other code without having to call the routine regularly, had to use a different prescale value and pre-load the counter to tweak the refresh rate but works great now

[@ratchet1freak]

I really enjoy this kind of arduino stuff. It's really hard to find someone willing to poke the control registers directly and go around the arduino's standard library.

[@user-vs1du9tl2p]

GreatScott is really great, Keep up the good work. Thumbs up!

[@5minutetimer]

This is amazing! Thanks for doing these!

[@qps9380]

Hi, any chance you could do a video on the HC-12 wireless module and the Arduino? You did the HC-05, so could you do this one too? I found out about it today and I would like to learn more about it. Thx!

[@ArthurIslamRU]

Thanks a lot dear Scott for your knowledge

[@irgski]

What's the (Arduino?) development board shown at your intro with the port LEDs, RPGs and LCD?

[@shubhamadtp]

So much information packed in one video. Error data limits exided

[@Axelios]

excellent video. i learned a lot about how to use an arduino beyond the included libraries

[@greatscottlab]

Awesome!

[@clivemayo4049]

Great video, you've made it so easy to understand, Thank you.

[@brzydka_i_bestia]

Great video, very helpful keep up the good work!

[@Frisky0563]

Boy that was quick I had to replay many times lol great video I appreciate it

[@4-n0t-found-4]

Thank you for this video, it's exactly what I needed to get it 👍

[@BillySugger1965]

Great video Scott! I use the atXMEGA series of processors, and always run a 1ms interrupt which does just two things: it sets a sync flag, so I can synchronise main loop processes to the timer without having interrupts disabled for a long time in the ISR; and increments a signed long value called time, which I use to keep track of timeout conditions for processing. Very powerful, takes very little processor resource and ties up the processor in ISRs (which block other interrupts) the least.

[@HersonBagay]

The xmegas support multilevel interrupts so you can always interrupt an ongoing ISR. Perfect for ultra time critical task

[@Delali]

This is just what i need. Thank you Mr. Scott

[@abdulhakeemkan]

Hi , GreatScott , how can we manipulate timers to create phase shifted Pwm , inverted sometimes dont help when you want minimum duty cycle on positive sides , i dont have a Oscilloscope to test techniques

[@juanrobertocuellarlozano5646]

Hey great scott quick question shouldnt you get 2 lines printed on the serial comm at 0.5 second mark? as the 1/4 sec interrup and 1/2 sec interrup should activate or one cancels the other one how is that supposed to work?

[@IndieSamurai101]

Man you are so good at electronics! Wish you were my physics teacher!

[@Remy561]

Great video, was easy to follow! (as an embedded systems student)

[@ferr4226]

at 7:05 ca. I dont quite understand the timer intervall is for compb and compa the same with 500ms? because it needs 500ms to reach 15624 again after reaching it for the first time. Is there anyway to use 1 Timer an get one ISR updating every 200ms and anpther every 500ms? or do i need to configure another timer for that?

[@BreakingYTown]

you are a mind reader...I was just thinking that there has to be a better way for my IOT home automation devices to poll the server without clogging the loop function...this is pretty awesome!!! thanks for the help

[@hubercats]

Very helpful video. Thank you!

[@GiancarloAllasia]

What is the demoboard that you show in the first part of the video?

[@PCBMakerBD]

I am from Bangladesh, Your working is great for new learner.

[@erygion]

@GreatScott! Where could I find one of those awesome MSP430 boards? I can't find it anywhere, please help! 😅

[@xyoxa6977]

Hey Scott, i'm working on a project where the Arduino Nano needs to wake up from sleep mode every 8~16h without external interrupt. Any idea whats the deepest sleep mode I can use and how to wake it up? Cheers

[@aps7637]

i have a 5v soldering iron are those irons good for the job

[@your.free.electrons]

I loved this explanation...I'm presently working on a project with atmega 8a :')

[@curiegupta7585]

Thank you for sharing the knowledge :)

[@CJ-yj1qw]

Great video! very educational!

[@wiko211]

Great video, found it really helpfull while programming the arduino uno in pure C

[@johnkg702]

Is it possible for making a timer using Arduino which switch on light every day night and off after a period .

[@basvanharen2904]

Thats an awesome video! So can you also explain how your “great scott” leds on that perfboard works?

[@ankitgupta9008]

I was finding this video for months very important thanks subscribe to your channel

[@ferr4226]

holy, finally found my mistake after hours. thank you, good sir.

[@hanishgopi]

How to use 16 bit timer for digital read sensor value? please tell me

[@KanalMcLP]

Finally! I had to do his very complex and unnescessary before ... Would be nice if you said whats the slowest possible timer (where you dont have to count the ticks).

[@thekaratekid02]

Im having an issue calculating the effective frequency of my timer. With a prescalar set to 1024 on timer 2's 8 bit timer, I would assume that I get a frequency of 16000000/(256 * 1024) = about 60 Hz. Then I use the interupt to increment a variable called cycle. So by checking to see when cycle is greater than 180, I would think that this would give me a wait time of almost 3 seconds, but it is in fact almost instant and I need to wait for the cycle to go above about 1500 to get any sort of delay close to 3 seconds. Any idea what I'm doing wrong?

[@aadishmanrai8408]

Can you please write a code that i can upload in Arduino, I want a Small beep sound at 30mins, 1hr, 1:30hr, 2hr(all optional )

[@programer0713]

Ooookey, first GreatScott video that i dont understand completly.

[@souravmandal7534]

Thanks for this video it helps a lot, But I have a question, can we increase the sampling rate of arduino using timer or any other way.bcoz I want to built a class d amplifier using an attiny85, since you said using a uC in making a circuit is better than using many ICs.Thanks in Advance

[@Od3o_ela_sabil_rabek]

And Please What's The PDF you are using for this CHIP

[@yxcvbnmmnbvcxy544]

Intresting board at the beginning. What ist that and do you make a Projekt with in in the future?

[@ahmedejaz1125]

6:19 wouldn't both compare match interrupts A and B occur at same frequency?

[@user-lm1iw6jl5f]

Hello! What is the board you use in this video? Thanks for you video!

[@germas369]

thanks so much for this. i understand how timers work on microcontrollers and how pwm is generated, this is awesome. I just made a pwm on AT89C2051 chip :))

[@thorbennielsen3845]

Can you recommend beginner guide on how to set register on AVRs? And do you have the code uploaded somewhere?

[@jayanthabandara9871]

What a great explanation

[@caterinazanini8591]

what is the model of your microcontroller?

[@grigorecosmin]

Can someone help me with some advice? As I understand it, printing in an interrupt is bad because printing depends on interrupts. If I try the same code as he shows in the video I get some random values. Can someone explain what's wrong? Also, does TCNT1 resets itself once it overflows? I had a problem where I had to manually set it to 0 when the overflow interrupt ISR occurred or I would get some random values on an LCD triggered through a flag in that ISR.

[@abdallasaad2774]

Hi Great Scott, can you please help me? I have changed the default settings of Timer0 in Arduino UNO, that affects millis() and delay() . now They counts time slower than normal .I have tried to fix this proplem by burn the bootloader but Aduino IDE shows "Error while burning bootloader." what can i do to fix this?