Arduino Sketch with millis() instead of delay()

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  • Опубліковано 24 лис 2024

КОМЕНТАРІ • 311

  • @programmingelectronics
    @programmingelectronics  4 роки тому +15

    ****If you like this, I think you'll like the premium Arduino training we offer. You can check it out here**** bit.ly/3lHyzcB

    • @Darkstar327
      @Darkstar327 2 роки тому +1

      please make a video on arduino sensor kit i need help on it btw your videos are amazing

  • @cschmitz
    @cschmitz 5 років тому +69

    This is a great explanation. The visuals really help wrap your head around the concept. Thanks for the vid!

  • @AlienRelics
    @AlienRelics 5 років тому +27

    Using
    previousTime = currentTime;
    will introduce an accumulating error. The time to process the code within the if statement will add to the time and accumulate. For just blinking LEDs or some other none critical stuff, no big deal.
    But if you simply use:
    previousTime += interval;
    You've just gotten rid of the cumulative error.

    • @programmingelectronics
      @programmingelectronics  5 років тому +3

      Thanks for bringing this up Steve!

    • @AlienRelics
      @AlienRelics 5 років тому +6

      @@programmingelectronics It probably won't affect most of what people will use this for, but it is just the sort of thing to drive you crazy later when you can't figure out why your timing is slipping.

  • @johncorbishley1548
    @johncorbishley1548 4 роки тому +22

    I have always struggled with this, even with your videos from years ago. I have watched numerous videos and still struggled. This video is simply THE BEST!
    You have done so well as an experienced programmer to be able to explain to us newby's how this work is such an easy to understand way.
    I have been copying & pasting other peoples bits of code randomly getting results and as my projects get more complicated, that approach does not work.
    Well done, you are the best teacher on UA-cam for Arduino.
    No.1
    Numero uno!

  • @johnmitchell4836
    @johnmitchell4836 4 роки тому +1

    I think Micheal is THE BEST TRAINER out there to learn the basics of programming in Arduino!!! I've spent many hours watching all kinds of Arduino videos before I found Micheal's - Programming Electronics Academy. I signed up and watched ALL of his videos and it was well worth the money!!!
    I highly recommend it to anyone that is getting into Arduino programming. He is really, really good!!!

    • @programmingelectronics
      @programmingelectronics  4 роки тому

      Thanks so much for the kind words John! I am glad you are finding the training helpful!

  • @johnrees44..G4EIJ
    @johnrees44..G4EIJ 4 роки тому +4

    I'm an 'old timer', and after a year of struggling with the theory and even the basic concept of 'millis', I've finally 'got it'!
    Thank you for the best Arduino 'millis' tutorial, and it's been my good fortune to find it..I look forward to watching more of your videos in future.
    John.. Bristol.. UK

  • @epartsacc
    @epartsacc 2 роки тому +2

    This is the best "millis()" tutorial I have ever seen. Thanks so much for explaining everything clearly.

  • @shaswot
    @shaswot 4 роки тому +2

    love the simplicity you bring into the explanation..... i had been reading up on example codes to understand millis function and scratching my head over and over. I wish i had found this video earlier...

  • @wmrieker
    @wmrieker 6 місяців тому

    I like that the if statement works even when the counter overflows so it'll keep going after 49 days and not miss a beat.

  • @jandobbelsteen8953
    @jandobbelsteen8953 5 років тому +22

    The way you show it will usually work nicely. However, the interval at which you trigger your event will be at least eventInterval, but often just a little bit longer. This is because the loop also takes a little time. Sometimes you may want to be more sure that you always trigger your timed event at an 'exact' multiple of 'eventInterval'. In such cases it's better to update your 'previousTime' with the 'eventInterval', like so:
    previousTime = previousTime + eventInterval;

  • @whitejtw
    @whitejtw 3 місяці тому +1

    Wow this is so excellent. I've been bumping up against limitations imposed by my reluctance to learn this methodology but now I'm halfway through the video and excited about the possibilities this engenders.

    • @programmingelectronics
      @programmingelectronics  3 місяці тому

      Great! Timing can be a bear. Another thing you might consider is learning about RTOS for scheduling tasks.

  • @pedrofelipebezerra4491
    @pedrofelipebezerra4491 3 роки тому +10

    The best explanation I've ever seen about millis()

    • @P44L
      @P44L 3 роки тому

      true

  • @michaelg6327
    @michaelg6327 2 роки тому +1

    GOD BLESS YOU! You saved me from days of suffering! You are my Hero!!!

  • @AbhishekKanti
    @AbhishekKanti 2 роки тому +2

    Thanks a lot man!
    I watched numerous videos, but wasn't able understand the concept of space time along with black holes.
    But now I'm confident enough to derive E=mc².💪

  • @philipeanthonybattung3860
    @philipeanthonybattung3860 2 роки тому +1

    Oh you did great. This will help me on the annoying issue between RF transmitter not sending data because pulse sensor eats all the event

  • @madhukeshnp
    @madhukeshnp 4 роки тому +1

    The best explanation ever... the carrot example was just epic... every noob can understand..... thank you so much for the great tutorial.

  • @Khan_Rahman
    @Khan_Rahman 4 роки тому +4

    why cant every tutorial be like this. Love it best

  • @martinest9458
    @martinest9458 4 роки тому +9

    what a Legend ! i wish i would of found your videos earlier! Absolutely the best explanation of things. Thank you Sir!

  • @JeThKo_MSW
    @JeThKo_MSW 3 роки тому +1

    it was taking me forever to figure out why mine wasn't working, then i found out i had "==" instead of ">=" lol
    thanks for the very clear and concise explanation!

  • @matrix9134
    @matrix9134 2 роки тому

    When you saved me I really love that tutorial it's actually the best thing I've ever watched in the history of our doing it Tori old and I'm not even being hilarious that's the truth thanks man keep up the good work !

  • @ahmedessam9092
    @ahmedessam9092 2 роки тому +1

    You make everything look simple .
    Thanks

  • @omkarkhade4602
    @omkarkhade4602 4 роки тому +1

    You are my favourite teacher.
    Thanks a bunch 😀

  • @brucesmith9144
    @brucesmith9144 4 роки тому +13

    One thing that should be added to the code is a trap for when the value of the millis() function rolls over. Consider if your Arduino is being used on a long term basis exceeding the long int value maximum. The user would want a way to handle that condition and continue the event timer. One quick way would be to check if the new millis() time is less than the previous time then the event timer loop can be reset.

    • @Ruudrad
      @Ruudrad 2 роки тому +3

      The way the code is written, by subtraction of unsigned longs, it compensates for roll over. No additional checks are needed.

    • @____________________________.x
      @____________________________.x Рік тому

      I was just wondering about rollover

    • @wadebrewer7212
      @wadebrewer7212 8 місяців тому

      ​@@Ruudrad please explain a bit please. Is it in the code in your face code or firmware side that you simply do not see. As in...
      If I am using millis to run a tachometer on an engine, and using that tach value to hold ignition on (interlock if you will, if RPM drops it cuts ignition) it will not get the math wrong in seeing the correct rpm?
      The long term use case here is; the arduino is going to be powered on indefinitely monitoring a signal from inverter to start generator. Once the inverter calls, the arduino will sequence and start the generator. I dont want the roll over to cause am issue with a tach calculation inadvertently shutting down the generator.

    • @Ruudrad
      @Ruudrad 8 місяців тому

      @@wadebrewer7212 I initially also thought roll over would cause problems, however if you use longs _and_ subtract the unsigned longs (holding the output of the millis() function and/or the millis() function itself) the calculation will also work when millis() rolls over (I.E. goes from almost its maximum to just over zero). Strange but true thanks to how subtraction works on a microprocessor, which is NOT exactly the same as mathematical subtraction.

    • @wadebrewer7212
      @wadebrewer7212 8 місяців тому

      @Ruudrad Thank you tons. I was about to start researching for a work around. The community around this stuff is pretty great. Every once in a while you get the tool that talks down or "why do you want to do that project"....because I can....and at least for now...I am allowed.....lol.
      Even in my situation....reading and counting every quarter or half second for revolutions....even if it did send a call to shut off the system, the cycles are so quick I don't think it would actually shut down. But...sounds is like it's non issue anyway.
      Again, thank you for the input and much appreciated.

  • @jameskalenga7546
    @jameskalenga7546 4 роки тому +1

    😄 The millis code was smart. I love that logic

  • @georgemugala4830
    @georgemugala4830 2 роки тому +1

    Best explanation ever on millis. Thanks alot bro

  • @mykolasbauza
    @mykolasbauza 4 роки тому +1

    Thank you for a wholesome explanation! Great stuff!

  • @vjdav6872
    @vjdav6872 4 роки тому +1

    Very clear explanation - I like that. I have taught some stuff in my one past life...Good job!

  • @ruwansamanpriya6085
    @ruwansamanpriya6085 5 років тому +2

    Wow.. That was the greatest tutorial I have ever seen on youtube...Thank you...

  • @jesus2639
    @jesus2639 5 років тому +6

    Thanks you make it so easy to learn

  • @RamyHelmy-vv3gq
    @RamyHelmy-vv3gq 2 роки тому +1

    You really have easily way to explain each point,thanks

  • @ludionieves5494
    @ludionieves5494 2 роки тому

    First off, thank you for your very informative video. I know this video is a few years old but I just came across it so my apologies for such a late comment.
    From your video, and from others, I understand that millis() starts as soon as the Arduino starts running and it keeps running, and increasing, as long as the Arduino is up, at least until it reaches its maximum value and restarts. I'm not sure that you actually CAN reset millis() from within code but everyone seems to say you shouldn't. Apparently doing so can break some libraries that rely on it.
    In order to understand millis() better I made a little project using code similar to yours to blink the built-in LED on and off at a preset interval while displaying current_elapsed_time (read from millis()) and previous_time, something similar to what you did in your code, and everything ran as expected. However, I noticed that every time I closed the serial monitor and reopened it the current_elapsed_time, which should display the current millis() value, returned to its starting value. The LED continues to blink at the proper interval while the monitor is closed, so I know the code is still running properly.
    Thinking there was a bug in my code I created a new, stripped-down program which only makes a call to millis() and prints the retrieved value to the serial monitor (see code below) and ran my test again. Same behavior. The code calls for the millis() value to be sent to the serial monitor directly - no massaging or assigning to a variable - and every time I close and reopen the serial monitor it appears to reset millis(). Not sure what is happening.
    Here is the simplified code I used to test:
    void setup() {
    Serial.begin(115200);
    }
    void loop() {
    Serial.println(millis());
    }
    The program runs as expected and, as you can see, there is nothing but the call to print the current value of millis() but millis() seems to be affected by the status of the serial monitor window. Is this normal? Am I missing something? 🤔
    Appreciate your help on this.
    Thank you.

  • @lmatrix6626
    @lmatrix6626 3 роки тому

    I think this is good idea if you need to step multiple stepper motors at the same time. When using delay() for moving stepper motors you can only move one stepper motor at a time

  • @ChadKapper
    @ChadKapper 3 роки тому +1

    These lessons are so well done!!

  • @kashpatel898
    @kashpatel898 2 роки тому +1

    Excellent explanation and coding, with great visuals 👏

  • @mariojulio993
    @mariojulio993 4 роки тому

    It becomes very easy to learn from you. You make everything looks so simple. Thanks

  • @HillsWorkbench
    @HillsWorkbench 5 років тому +1

    This detail on the mills() function has been very helpful to me, explains why a program I wrote a few years ago doesn't quite work as expected.

  • @romycruz4498
    @romycruz4498 4 роки тому +1

    wow that's awesome and well explained ! The presentation is very nice and clean and understandable ! but... what is it again ? ah, needs to rewind this utube vlog again & again.

  • @AerialPhotogGuy
    @AerialPhotogGuy 5 років тому +1

    Very Cool!!
    You come out with this video just in time for me to use millis() to toggle between volts and amps on an OLED display (without using delays, delays that long when added up would have made the loop way too long for this project).
    It took me a bit to figure out how to write the second section (like this:) (currentTime - previousTime >= interval + interval_1) I added the second interval time so I could set the volts code to display less time than the amps code since that's the one that needs to be read the most, but I got it. I'm sure I will eventually figure out an easier way but it's good for now and I'm proud of it! :-D
    The most valuable information in your video series is the fact that the timer continues to count up until the microcontroller is reset or turned off and on again.
    I now also realize that I can run more than one program from the same millis() function.
    It's kind of like calculating what needs to happen at different times of the day with a certain amount of time for each task. Yeah, I know, probably a screwed up analogy but there it is LOL :-)
    Until now I thought that the timer reset each time it was called for.
    Thanks!!
    Joe

  • @conversationwithgod272
    @conversationwithgod272 4 роки тому +1

    Really a great video.great people behind this Job...The visuals make everything so simple.thanks millions

  • @Le0mach
    @Le0mach 3 роки тому +1

    Hi! I'd like to thank you very much for the excelent explanation! I was struggling a bit with millis() until watched you videos. It saved me a lot of time and helped me to understand why my project wasn't working (that's the best way to learn something, by fixing it's bugs)! Keep on doing this awesome job, man!

  • @hobarey5029
    @hobarey5029 5 років тому +1

    the best tutorial on millis() ever... thanks...

  • @emmanuelegel21
    @emmanuelegel21 4 роки тому +2

    This is awesome! the best explanation ever about millis function. Thanks a lot... Poor millis can't catch the carrot XD

    • @rupert274
      @rupert274 3 роки тому

      You're mean, Emmanuel!

  • @ensarija
    @ensarija 3 роки тому +1

    Thanks for the extensive explenation.
    I made function out of this, which can receive interval in milliseconds and counter number, so it can be called multiple times and keep prevousTime in array for multiple counters.
    if(execDelay(2,1000)) {
    // Do stuff
    }
    bool execDelay(int instance, unsigned long v) {
    unsigned long prevTime[] = {};
    if(currTime - prevTime[instance] >= v) {
    prevTime[instance] = currTime;
    return true;
    } else {
    return false;
    }
    }

  • @jackmini1217
    @jackmini1217 3 роки тому

    enjoying this lessons. motivated to keep moving further. thanks a bunch.

  • @P44L
    @P44L 3 роки тому +1

    Very nice and easy to understand video, thanks!

  • @plugnugget3672
    @plugnugget3672 Рік тому +1

    Smoooth animation bro. I love the homey type design, backdrop is really chill. Casually printing ice ice bb to the serial monitor lol. Explained it fantstic with the carrot comparison. Sending money but more importantly encouragment. Your great at this! keep going - seriously
    God Bless ;)
    - J. T

  • @pixies4ever324
    @pixies4ever324 10 місяців тому +1

    haha.. being mean with the carrot and millis() function. love it.

  • @naboulsikhalid7763
    @naboulsikhalid7763 5 років тому +1

    Great. first time explained, first-time understood. thank you very much

  • @annie_obi
    @annie_obi Рік тому +1

    I found your video very helpful. Thank you!

  • @j.w.8663
    @j.w.8663 11 місяців тому +1

    @5:31 Aah, I see what you did there: The Neutron Dance! 😆

  • @ChandanKumar-kr2kj
    @ChandanKumar-kr2kj 2 роки тому +1

    Great video. Thanks a lot for making this video.

  • @guidoramacciotti3503
    @guidoramacciotti3503 4 роки тому

    Very clear and simple explanation . Thank you!!

  • @lindsaydempsey5683
    @lindsaydempsey5683 3 роки тому +4

    Great video, thank you. Question, will that code work correctly when millis() overflows and starts counting up from zero?

  • @hamouz718
    @hamouz718 4 роки тому +1

    Very entertaining channel, love your videos, keep them coming

  • @reylepiten3722
    @reylepiten3722 4 роки тому +1

    Thanks for this great explanation..it really helps a lot...

  • @stevenstraker5105
    @stevenstraker5105 2 роки тому +1

    Great video, thanks! One comment though, I think we could also use a modulus operator to manage the event intervals. This would also cause it to run at millis() == 0, but we can use an additional clause to limit this. Perhaps something like:
    if( currentTime > 0 && currentTime % eventInterval == 0 ) { ...

    • @stevenstraker5105
      @stevenstraker5105 2 роки тому

      Actually, it seemed like this would work in theory, but there needs to be a buffer, as the code would run multiple times at each interval. I guess this is why the lastTime variable is introduced, so that we can ensure the code runs only once per interval. Makes sense - I stand corrected!

  • @Jevajs
    @Jevajs 4 роки тому +1

    you could do the same logic and prob have better runtime using (inside the loop)
    if (millis() % interval == 0) {
    // do whatever you want here for every x amt of milliseconds
    // where x = interval
    }

    • @banzaiiiiii
      @banzaiiiiii 3 роки тому

      In an Ideal situation, you're right. But in reality millis would almost never hit exactly your interval. That's why >= is used in the video, but with your code >= wouldn't work.

  • @maxabeles
    @maxabeles 3 роки тому +1

    Simply grand.

  • @fullbridgerecrifier
    @fullbridgerecrifier 6 місяців тому +1

    Thank you,
    That saved my life ❤

  • @omkarbansode6305
    @omkarbansode6305 10 місяців тому +1

    thankyou so much ,it was a really big help

  • @mlggeek1812
    @mlggeek1812 5 років тому +1

    Great video! Going to implement it to my project ASAP

  • @kpro-ke5hd
    @kpro-ke5hd 11 місяців тому

    That actually make sanse,Thanks for the vod.

    • @kpro-ke5hd
      @kpro-ke5hd 11 місяців тому

      We dont have to crate a variable(previousTime) if we only wanna execuit the if once.but to update the timing we have to substract the (currentTime from the previousTime)

  • @VasilisKarastergios
    @VasilisKarastergios 5 років тому +1

    You are awesome, I can't wait for the next video! 👍👍

  • @davidsvarrer8942
    @davidsvarrer8942 2 роки тому +1

    Hey Programming Electronics Academy. Your code is good if you want 1000 milliseconds between events, which ie. takes 10 milliseconds to execute. However. If you want things to happen every 1000 milliseconds, sharp, then you will need to add 1000 to the carrot, instead of moving ahead with the relative time. You can say, that you would add 1000 to the limit of 1000 every time, making an absolute goal, rather than adding to the relative currentTime.

  • @andrasparanici5491
    @andrasparanici5491 4 роки тому +1

    The best lesson!

  • @hanac5586
    @hanac5586 4 роки тому +1

    Thank you so much 🤍
    + extra points from ice ice baby

  • @RixtronixLAB
    @RixtronixLAB Рік тому +1

    Nice info, well done, thanks for sharing it :)

  • @husseinnejah5337
    @husseinnejah5337 4 роки тому +1

    this is legendary! massive Thanks

  • @Simoooooooonn
    @Simoooooooonn 3 роки тому +2

    Great video

  • @mohamedsoftline1
    @mohamedsoftline1 4 роки тому +1

    This is a great explanation.

  • @ankushchauhan5752
    @ankushchauhan5752 3 роки тому +1

    Thank you sir i really appreciate that....😎😎

  • @mridulsarkar9015
    @mridulsarkar9015 3 роки тому +1

    Very nice explaination. Thanks

  • @Sarvesh1110
    @Sarvesh1110 6 місяців тому

    Great explanation sir thank you 😁❤

  • @simplyjust-6912
    @simplyjust-6912 2 роки тому +1

    Tyyyy this was such a good video 😄

  • @NCVluminati
    @NCVluminati 7 місяців тому

    thankyou, I needed this

  • @TrentSmith-m4h
    @TrentSmith-m4h Рік тому +1

    Same idea…. Slightly different solution:
    if(millis() % 1000 == 0))
    {
    // make your fish taco
    }
    IOW use modulus operator… any number divided by 1000, then take the remainder. When remainder is zero, millis is a multiple of 1000.
    Also: You can make an LED ‘flicker’ by using the random function to change the 1000.

    • @edgarbonet1
      @edgarbonet1 7 місяців тому

      This is a bad idea for two reasons:
      1. If your loop() ever takes more than one millisecond to run, you may well miss the specific millisecond you where aiming for.
      2. millis() doesn't count every single millisecond: as it is only updated every 1024 µs, it skips one value roughly every 42.7 ms (it skips 42, 85, 127, 170, 213, etc.).

  • @CommenterTheMan
    @CommenterTheMan 3 роки тому +1

    This is very informative

  • @sainumkhey8849
    @sainumkhey8849 Рік тому

    the best explain tutorial lesson thanks a lot 👍

  • @HARSH9909
    @HARSH9909 4 роки тому +1

    Such a nice video 🙂

  • @neelmehta100
    @neelmehta100 4 роки тому +1

    I like to imagine the millis being waves in the ocean and we are the Surfers trying to ride those waves.

  • @martinsiolowosoran5242
    @martinsiolowosoran5242 5 років тому +1

    very interesting, a good teacher

  • @DrRusty5
    @DrRusty5 2 роки тому +1

    Took a while to get millis() working in my code but so much better than using delay.

    • @programmingelectronics
      @programmingelectronics  2 роки тому

      Nice!

    • @DrRusty5
      @DrRusty5 2 роки тому

      With millis() the serial data continues to be read, where previously it was clear to see on the Serial Monitor that delay had simply frozen it dead for the length of the delay.

  • @vamshikp.j.8592
    @vamshikp.j.8592 7 місяців тому +1

    amazing explanationnnnnn

  • @Ivan-wb4id
    @Ivan-wb4id 4 роки тому +1

    After some time , millis wont be precise. Is there a way to restart millis after 1 second has passed. Like count up to 1000 milis, and then restert it to count again to 1000?

  • @muhammadbilal2000
    @muhammadbilal2000 4 роки тому +1

    Sweet explanation :) Thank you

  • @yuriu8
    @yuriu8 4 роки тому +1

    Wow mate thanks it amazing lessons

  • @Namai.
    @Namai. 4 місяці тому +1

    very well explained, thx

  • @attalaw36
    @attalaw36 4 роки тому +1

    thank you

  • @punjabilog
    @punjabilog 5 років тому +1

    Thank you very much Sir... Great Video

  • @dezmach93
    @dezmach93 Рік тому

    Wow, you're the best!!! thanks!

  • @Val-eq4sg
    @Val-eq4sg 5 років тому +1

    Muchas gracias, At last someone took the time to explain this, I really needed it thank you kind GOD of code..

  • @vasha1548
    @vasha1548 3 роки тому +1

    love it

  • @katrinejensrud537
    @katrinejensrud537 5 років тому +1

    fantastic video!thank you!

  • @hobarey5029
    @hobarey5029 5 років тому +2

    very informative...thanks a lot...

  • @umiturgutaswwsa
    @umiturgutaswwsa 3 роки тому +1

    What a great video.

  • @lucienramono
    @lucienramono 3 роки тому +1

    so nicely explain thank you :)

  • @karanparve1734
    @karanparve1734 4 роки тому +1

    wow its amazing...

  • @bl4ckd0n4ut2
    @bl4ckd0n4ut2 2 роки тому +1

    Thanks mate

  • @peterchrien
    @peterchrien 2 роки тому +1

    very nice video

  • @Krystino
    @Krystino Рік тому

    Amazing explanation, great thanks. Thus, there is something I don't manage to understand. If I want a start point not equal to the interval, I mean for example an event to start at 30 seconds, and to be repeated 60 seconds later on. Do I need one more variable to be created? Kind regards.