I am impressed , and this tutorial has made me travel to the gate of Multi tasking. Yet I have no idea how will i implement the timer interrupts in my programs where lots is going on, 6 servos , GY 80 , 6 ultrasound range finders , distance ,comparisons etc etc but I Thank you for your generosity for Extending this charity of Knoledge. I salute
Excellent tutorial. I have gone through at least a dozen tutorials claiming to explain how timer interrupt works, but none of them made any sense because they added so much bloat. Keep it up.
One of the better tutorials out there. I understood all the presentation which was presented in a very simple way so that all could understand. Thanks so much and thanks for turning me onto the Timer1 library.
Well done. It wasn't until I watched your video that the light bulb went off in my head on how I can use the hardware timer to facilitate the variable control I need to operate a stepper motor. I particularly like the single line code for flipping pin state. Very elegant. Thank you.
Little correction: Timers are 0, 1, 2. Not 1, 2, 3. Timer 0 is 8 bit used tor timer functions delay(), millis() or micros(). Timer 1 is 16 bit used for the servo library. (Which you can tweak with Timerone.h library). Timer 2 is also 8 bit and used for the tone() function. This for the UNO. Arduino Mega has 0-4. Nevertheless, nice tutorial :-)
Great video man, finally someone who is making a little more advanced class arduino videos, we all know there are a zillion arduino for beginners videos out there. I really like being taught the code in detail like that. Will you do some advanced coding for arduino videos, that would be awesome with your teaching style. Thank you for your work, I subscribed.
Thanks for going though the code and explaining it line by line. I was always confused by the bitwise operator but your explanation really helped me get it.
great Video. A little addition: the shown big crystal 16 MHz is not for the Arduino, but for the USb Controller. Very often the arduinos have a ceramic resonator, very little and very inaccurate, not good for a clock. This resonator sits nearby the microcontroller. Sometimes (here?) it is a real quartz crystal...
Was going to say the same thing (although very late to the party). The resonator is shown at 3:47 under the "ITA" of Made in Italy. I assume they are using low spec stuff. The muRata brand Cerelock models of resonators come in tolerances of +/- [0.1, 0.2, 0.5]%. That's a reputable brand too. I assume the Ardy1 clones are probably extra loosey goosey. It's might be safe to assume we've got a frequency between 14.5MHz and 17MHz...-ish. ...but how many of us have a quality frequency counter with a calibrated and certified disciplined oscillator to say for sure? Even the best 1% of us hobbyists are doing good if we can use a trimmer capacitor to tune a crystal circuit in hopes that we might make one circuit just as wrong as some other none calibrated uncertified device we have ;) -Jake
lol ive hand wired many circuit boards with just the atmega 328 and a 16mhz crystal, never noticed or looked, those boards don't use the crystal for the 328, stopped using them long ago. its very obvious now though.
Great tutorial Tom! Clarifed a lot for me, particularly the toggling. Can you have multiple interrupts triggered by Timer1 at different counts to do different things? Such as ISR1, ISR2, ISR3 etc? Thanks!
Many thanks for your video and information given. Only the pin 13 is managed by the bit N°5 of the port B register and not by the Bit N°1 like in your video !! (Port B register : Bit0 for pin 8, Bit1 for pin 9, Bit2 for pin 10, Bit3 for pin 11, Bit4 for pin 12 and Bit5 for pin 13).
This Crystal you mentioned is only used for the ATmega that does the USB communication. The ATmega328 on an Adruino Board uses a cheap and very inaccurate resonator instead, that is placed right next to the side of the ATmega328. It's a pity they did not export the USB-ATmega clock to make use of it as well for the main processor (ATmega328). But sadly that is the way it is... Apart from this little misinterpretation, well done!
Hello, I am using the Arduino Mega R3 board and can you tell me if there is a version that will support the ATMega2560 micro like the one on the Arduino Mega board? Thanks Tim
the 16 MHz crystal u showed is for usb to serial converter and not for atmega328p chip. the atmega's crystal is the small one below where 'made in Italy'is written on silkscreen
Quick question: Yesterday a colleague and I actually measured the Arduino with an oscilloscope, and we noticed that below a delay of 1, weird things start to happen. Basically the signals sort of get corrupted and the oscilloscope does not know which one is the correct signal. We're trying to build a visual light communication (lifi) system, with arduinos powering the LEDS, and we need to brighten / dim the LED lights very quickly, switching among analog voltage states in order to transmit a modulated signal at at least 300kb/s. Do you have any advice on how to do this from a software perspective, and do you think arduino would be capable enough to achieve this? Thanks so much! - Kelsey Cameron UCF Student
Hello Mr.Tom is it possible to measure temperature & save data into sd card and check temperature using if condition to activate a relay or not?! it seems like I am trying to do 4 tasks in uno I tried timer1 and timer3 also tried to do use loops inside main loop but couldnt can you advice me a way? thank you
If I want to switch on and off pin 6 of digital pins after particular microseconds ,which is in port D without affecting other pins ,instead of using digital write and delay function twice for on and off ,what should I do?
Also, subtraction means that you have another hardware delay of multiple cycles (5 if I remember right), whereas xor only uses 1 gate, so it is way faster.
@Jungguk Kookie so my issue was actually a little bit different, I discovered that the oscilloscope I was using was not for the correct frequencies and it wasn't doing at all what I thought it was. However, I did some tests with Arduino a while back and from what I remember, the frequency timing significantly decreases in accuracy as you get faster and faster. Yes, a hardware crystal for a clock would work significantly better but if you need this for a real time operating system, Arduino isn't recommended. I know a few systems that would work, so if you're interested, message me back! 😊
can you tell me how to do this for two arduino boards..without using any protocol like I2C or SPI..? I WANT TO RUN ONE ARDUINO AFTER OTHER AND VICE VERSA
hello i work for long time to understand pin change int but it doesn't work i want to have code wich use pin 7 (on arduino uno ) as pin change int to turn on and off led on pin 13
i downloaded a library that change all pin on arduino uno into interupt pin. #include #include #include #include #define echoPin 7 attachPCINT(digitalPinToPCINT(echoPin), echo_Isr, CHANGE); it work. but cant do two function on one pin when attach another function..
Yes but I am going to re-install it to make sure it is not corrupt in any way. I'll try to compile again tomorrow. Have you tried to compile timer interrupts on a Nano using the TimerOne library?
I have not built any projects with the nano yet. I did purchase an adafruit trinket though. With the newest IDE you just go to sketch---> include library and go to---> library manager and search for timerone and select install.
I am impressed , and this tutorial has made me travel to the gate of Multi tasking. Yet I have no idea how will i implement the timer interrupts in my programs where lots is going on, 6 servos , GY 80 , 6 ultrasound range finders , distance ,comparisons etc etc but I Thank you for your generosity for Extending this charity of Knoledge. I salute
Excellent tutorial. I have gone through at least a dozen tutorials claiming to explain how timer interrupt works, but none of them made any sense because they added so much bloat. Keep it up.
One of the better tutorials out there. I understood all the presentation which was presented in a very simple way so that all could understand. Thanks so much and thanks for turning me onto the Timer1 library.
I believe that crystal is for the USB chip. The 16Mhz resonator just above the 328 is what the controller uses. Good video.
I love such traditional handwriting teaching style, it is much easier to fellow the step of the teacher
You are very good at explaining these concepts. I found the video clear and easy to follow. Much appreciated.
Excellent!!!! You spoke clearly for people whose English is a foreign language
Well done. It wasn't until I watched your video that the light bulb went off in my head on how I can use the hardware timer to facilitate the variable control I need to operate a stepper motor. I particularly like the single line code for flipping pin state. Very elegant.
Thank you.
Little correction:
Timers are 0, 1, 2. Not 1, 2, 3.
Timer 0 is 8 bit used tor timer functions delay(), millis() or micros().
Timer 1 is 16 bit used for the servo library. (Which you can tweak with Timerone.h library).
Timer 2 is also 8 bit and used for the tone() function.
This for the UNO. Arduino Mega has 0-4.
Nevertheless, nice tutorial :-)
haven't looked deeper but is there something like waitforinterrupt() ? that would be perfect for delay()
Little correction:
Timer 0 is 8 bit used *for*.....not tor
Great video man, finally someone who is making a little more advanced class arduino videos, we all know there are a zillion arduino for beginners videos out there. I really like being taught the code in detail like that. Will you do some advanced coding for arduino videos, that would be awesome with your teaching style.
Thank you for your work, I subscribed.
Thanks for going though the code and explaining it line by line. I was always confused by the bitwise operator but your explanation really helped me get it.
great Video.
A little addition: the shown big crystal 16 MHz is not for the Arduino, but for the USb Controller. Very often the arduinos have a ceramic resonator, very little and very inaccurate, not good for a clock. This resonator sits nearby the microcontroller. Sometimes (here?) it is a real quartz crystal...
Was going to say the same thing (although very late to the party). The resonator is shown at 3:47 under the "ITA" of Made in Italy.
I assume they are using low spec stuff. The muRata brand Cerelock models of resonators come in tolerances of +/- [0.1, 0.2, 0.5]%. That's a reputable brand too.
I assume the Ardy1 clones are probably extra loosey goosey. It's might be safe to assume we've got a frequency between 14.5MHz and 17MHz...-ish.
...but how many of us have a quality frequency counter with a calibrated and certified disciplined oscillator to say for sure? Even the best 1% of us hobbyists are doing good if we can use a trimmer capacitor to tune a crystal circuit in hopes that we might make one circuit just as wrong as some other none calibrated uncertified device we have ;)
-Jake
Wrong.
Write.
lol ive hand wired many circuit boards with just the atmega 328 and a 16mhz crystal, never noticed or looked, those boards don't use the crystal for the 328, stopped using them long ago. its very obvious
now though.
Very clear talk, steady flow, and followable
You are a great instructor with deep knowledge.
Great tutorial Tom! Clarifed a lot for me, particularly the toggling. Can you have multiple interrupts triggered by Timer1 at different counts to do different things? Such as ISR1, ISR2, ISR3 etc? Thanks!
Great explanation. Your digitalWrite() statements much more elegant than the if..else statements commonly used to toggle
really helpful.god bless to guy who designed timer one library
That was a fantastic explanation of a bunch of different concepts. Thanks :)
Many thanks for your video and information given. Only the pin 13 is managed by the bit N°5 of the port B register and not by the Bit N°1 like in your video !! (Port B register : Bit0 for pin 8, Bit1 for pin 9, Bit2 for pin 10, Bit3 for pin 11, Bit4 for pin 12 and Bit5 for pin 13).
Very helpful. I liked the added info re using ! instead of ^1
A clear explanation and most helpful.
I'm looking for the tutorial on hardware interrupts - specifically for using a button that you mention in this video. Can you direct me to it?
Best tutorial Ever. I love it. Do you have video on Hardware interrupts? If not please make one.
This Crystal you mentioned is only used for the ATmega that does the USB communication. The ATmega328 on an Adruino Board uses a cheap and very inaccurate resonator instead, that is placed right next to the side of the ATmega328. It's a pity they did not export the USB-ATmega clock to make use of it as well for the main processor (ATmega328). But sadly that is the way it is...
Apart from this little misinterpretation, well done!
Hello, I am using the Arduino Mega R3 board and can you tell me if there is a version that will support the ATMega2560 micro like the one on the Arduino Mega board? Thanks
Tim
Best timer tutorial ever! Wow, thanks!!!
I like the 1st toggle string. Might be useful.
I would like to thank you for your time. It was very usefull for me. God bless you.
Excellent tutorial, helped a lot with my understanding! Thank you.
the 16 MHz crystal u showed is for usb to serial converter and not for atmega328p chip. the atmega's crystal is the small one below where 'made in Italy'is written on silkscreen
but anyways that crystal is also 16MHz
What gauge wire are you using for connections?
Quick question: Yesterday a colleague and I actually measured the Arduino with an oscilloscope, and we noticed that below a delay of 1, weird things start to happen. Basically the signals sort of get corrupted and the oscilloscope does not know which one is the correct signal.
We're trying to build a visual light communication (lifi) system, with arduinos powering the LEDS, and we need to brighten / dim the LED lights very quickly, switching among analog voltage states in order to transmit a modulated signal at at least 300kb/s.
Do you have any advice on how to do this from a software perspective, and do you think arduino would be capable enough to achieve this?
Thanks so much!
- Kelsey Cameron
UCF Student
Excelente tutorial mi estimado justo lo que necesitaba, gracias amigo
Hello
Mr.Tom
is it possible to measure temperature & save data into sd card and check temperature using if condition to activate a relay or not?!
it seems like I am trying to do 4 tasks in uno
I tried timer1 and timer3 also tried to do use loops inside main loop but couldnt
can you advice me a way?
thank you
Thank you for the helpful video! It would be great if the video of your code were easier to see. It's fairly dim.
Thank you very much for such great tutorial.
Is there a tutorial on how to use SAMD_TimerInterrupt library?
If I want to switch on and off pin 6 of digital pins after particular microseconds ,which is in port D without affecting other pins ,instead of using digital write and delay function twice for on and off ,what should I do?
Thanks for such a nice and excellent video tutorial.
Can you please help me how to calculate rpm of a trigger wheel using hardware interrupt? Can you please post it? How to count the frequency?
to toggle you could do a really easy way : digitalWrite ( 13, 1 - digitalRead (13))
That's true but the problem is that digital write and read have a lot of extra stuff that slows it down a lot, for high speed applications.
Also, subtraction means that you have another hardware delay of multiple cycles (5 if I remember right), whereas xor only uses 1 gate, so it is way faster.
@Jungguk Kookie so my issue was actually a little bit different, I discovered that the oscilloscope I was using was not for the correct frequencies and it wasn't doing at all what I thought it was.
However, I did some tests with Arduino a while back and from what I remember, the frequency timing significantly decreases in accuracy as you get faster and faster. Yes, a hardware crystal for a clock would work significantly better but if you need this for a real time operating system, Arduino isn't recommended.
I know a few systems that would work, so if you're interested, message me back! 😊
@Jungguk Kookie I don't know for sure if beaglebone would support that but let me ask around today where I work and I'll get back to you 👍
Helpful tutorial. Thanks bro
can you tell me how to do this for two arduino boards..without using any protocol like I2C or SPI..?
I WANT TO RUN ONE ARDUINO AFTER OTHER AND VICE VERSA
Thank you for a GREAT tutorial : )
Excellent class. Thanks
how to compare two interrupts in Arduino with in the loop.
Thank you for this tutorial. But how to stop interrupt after a specific time.
how can i turn my fan off after 3 minutes using arduino ?
I meant which library can i use and how the code should look like ?
Great tutorial !
I was expecting timer interrupts tutorial, and i get 20 seconds of that with major mistakes. The rest of video is about something else...
completely right, as a student in Nottingham, you can't imagine how cruel our teachers were to ask us learn Arduino totally by ourselves
You spent 1/3 of your and our time, explaining toggle and boolean operation which have nothing to do with the subject.
I Need to set secunds , how?
hello
i work for long time to understand pin change int but it doesn't work
i want to have code wich use pin 7 (on arduino uno ) as pin change int to turn on and off led on pin 13
+Adil Machrouki Only pins 2 and 3 can be used for hardware interrupts on the Arduino Uno. Pin 2 is INT 0 and Pin 3 is INT 1
i downloaded a library that change all pin on arduino uno into interupt pin.
#include
#include
#include
#include
#define echoPin 7
attachPCINT(digitalPinToPCINT(echoPin), echo_Isr, CHANGE);
it work. but cant do two function on one pin when attach another function..
That's not the crystal that the atmega uses. There is another, smaller, one close to the pins 9 and 10. That one is also 16MHz.
"timerIsr was not declared in this scope". Is there something wrong with the library?
Did you restart the IDE after installing the library?
Must've been it.
No it still doesn't work.
Awesome Tutor ;-)
very good tutorial
Try this on a Nano which also uses a 328P Atmel processor. You can't even get your example to compile.
Do you have the timerone library installed?
Yes but I am going to re-install it to make sure it is not corrupt in any way. I'll try to compile again tomorrow. Have you tried to compile timer interrupts on a Nano using the TimerOne library?
I have not built any projects with the nano yet. I did purchase an adafruit trinket though. With the newest IDE you just go to sketch---> include library and go to---> library manager and search for timerone and select install.
Tom, I deleted the library and re-installed TimerOne and now it works. Thanks for your help!
Why doesn't TimerOne work with the Nano?
Here is a link to some information I found on the nano and timers stackoverflow.com/questions/16058695/arduino-nano-timers
Thank you very much!
thank you very much
THANKS A LOT
nice Work ^_^
Thank you sir
Thank you.
thanks
Thanks ....