Really clear, careful explanation with all the details. Many thanks!

This is perfect and shows how to elegantly solve common problems with interupts. The program runs right away without any changes on my Pico with exactly the same behaviour as presented in the video. Great learnings in less than 30 minutes. 😀

I've watched a couple of your videos now and they are excellent. So many RPi Pico/MicroPython videos are so introductory they never cover poweful features like IQR or component issues like switch bounce.

Hi Chris - often folks complain about LED projects as they are so basic. However, once you get the concept that signals are just merely being passed and the same philosophy can be applied. Understanding the concept instead of this being an isolated solution you can really make some progress in your own code. After watching your video I rewrote my code for my wheel encoders and set both IRQ and Timers to make a more efficient and elegant solution. Many thanks!!

Excellent tutorial. IRQs are something of an enigma to most developers outside of embedded systems development and your tutorial explains and demonstrates the subject elegantly. Thank you for taking the time to create such a great resource. More please!

Thanks for awesome explanation on dealing with interrupts and key-bounces!

Hello Chris I have been playing with interrupt driven encoders using interrupt and you have some “features “ in your code. When you initialise the ISR you set up Rising or Falling edges. Note if you don’t specify rising and falling in your code it defaults to this without setting it explicitly. Secondly you probably don’t need to stop the interrupt in the handler given that interrupt in micropython based on a scheduler and are not a true interrupt. I haven’t tested this but I doubt you can enter it multiple times. Finally when you re-initialise the interrupt at the end of the handler you have forgotten to explicitly set if you want rising or falling. In your case you got lucky as not explicitly setting it gave you the functionality required. Note I found all this out trying to detect a rising edge. It worked first time but then defaulted to interrupt on the rising and falling edges. Hopefully this makes sense and comments made in good faith to aid our learning. Best regards Chris

thanks a lot, very good tutorial

in the micropython irq handler you can do :: state = machine.disable_irq() global x,y,z ... other code ... at the end do :: machine.enable_irq(state) to stop any interrupt interfering also in the handler you can find out which situation called the handler, when using IRQ_RISING|IRQ_FALLING combo print( pin.irq().flags() ) will show if it was Rising or Falling if you need your code to act differently on each ... flag returns a number (4/8/12), test it out ( might need to do short press and long press testing )

Thanks Chris! really helpful.

Well done. 😀

great stuff thanks Chris 👍

very good tutorial, thank you

Thank you, very clear to understand. I am still wondering weather it would be "faster" to avoid as much tests as possible, maybe by defining two specific handlers, one for the OFF transistion, the other for the ON ? I made a few tests, nothing obvious.

Awesome Thanks

Thonny (python) is interpreted and runs slow so you are just letting the execution of the code be your debounce timer. Run it in C and you are likely to see[on off on] from the key bounce. Also there is no difference in triggering on 2 statements to transition high, transition low, vs the statement where you check the or condition. An interrupt will never be simultaneously transition high and transition low at the same exact same time..

First great set of videos Question - Could instead of using the Global Pb_Switch_State why not use the Warning_LED.Value() so the if and elif lines in the code would be : if (Pb_Switch.value() == 1) and (Warning_LED.value() == 0): elif (Pb_Switch.value() == 0) and (Warning_LED.value() == 1): What are your thoughts?

What would be your thoughts regarding speed on using an object to store the state rather than a global declaration?

Hello Chris! This video is awesome as we said in the 1980 in high school! The example is to keep light on while pushing button. If I wanted to hold light state on by pushing button ounce and not have to keep holding to keep light on. Light would stay on until push button was pushed again to turn light off. How would I have to change code. Thank you so much for your time and great videos.

Is it possible for an interrupt function to affect the main loop? I tried using an interrupt to change a variable that was used in the main loop, but unfortunatly the loop would resume in the state that it was before the interrupt was triggered. Is there a work around that?

Would you know how to use interrupts in the Arduino IDE, though, rather than using micropython or circuitpython?

Chris - Any updates using Pico interrupts with the Arduino IDE 2.2.1?

hello! how are you ? ... why do you put that delay in your while loop?

When you simply turn off the interrupt while executing you may end up with the actual pin state being the opposite before you're done processing the code if the code isn't fast enough. In theory. With C I've usually turned the interrupt off, done the processing and check the actual pin state right before executing the result of the processing... Practically, since a button is a human interface, starting a timer to wait until a 100th of a second before double checking will not be noticeable to the human brain. But it'll eliminate the jitter that a button may perform as well as any static electric discharge triggering the interrupt, putting your statemachine into an inverted state. Edit: you do teach some important lessons about the principles about how to handle interrupts, i just feel that you haven't tried fringe hardware with a lousy bounce going on. It's a common trait amongst theoretical programmers to trust the hardware and environment too much.