A great video as always Andreas! I happened to have the C++ dev environment setup on the bench using a Raspberry Pi 4 and therefore was able to quickly measure the interrupt response time with my oscilloscope. This turned out to be 1.1us when built for debug and 1.0us for release. The release version seems to have some jitter of around 0.1us whereas the debug version doesn't which seems a bit unusual.

shorting the pico's RUN pin to ground causes a hardware reset, it's a pity that there isn't a built in reset button, but adding one isn't too hard

When you made this video, I was miles away from securing a job in engineering. No degree, no money, self-study. A year later, Mr. Spiess set me on a journey with the pico that allowed me to secure a job as an RF Technician (en route to engineering position) for municipal districts and emergency service radios. Thank you for all the immensely valuable information and education and it is not for granted!

Nothing like your weekly dosage of your guy with the swiss accent. :)

The cat says: "no more interrupts".

If you're afraid of wearing out the connector you can always try unplugging the other end of the cable ;-)

you can reset the pico by connecting the "run" pin to ground.

Fastastic and practical info on the fundamentals of utilizing multiple cores! Your explanations are so clear and concise, thank you!

greets from ukraine! u have very good english, easily understandable even for non english-speaken guys like me. doing electronics as hobby for 20 years, but still can get some new knowledge from any of your videos. so what we can say about newbies. its a heaven for them. keep it up, man

freeRTOS !! Yea, I just started reading the official docs last week. Half way through mastering freeRTOS already. Cool stuff in there. These topics will advance/enhance our lives 4 sure

Just received some picos yesterday and was interested in using both cores. Perfect timing discovering #372. Thank you!

I really like the quality of your explanations. Great visualization and you show the examples very detailed. Thanks for enlightening me so often. I am still pretty new to the topic, but I had lots of fun so far.

As usual a great video with excellent resource links. The Getting started book is worth five pounds, whatever that is in dollars. Threads and interrupts were explained so that mere mortals can grasp it. Keep broadcasting!!

Quality content as always. - And not a mix-up of examples from the book, another unboxing, introduction etc. - He sets the bar high for other KZfaqrs. Thank you!

I love your deep dives Andreas. I'm glad you exist to do them. I had a chuckle at the arduino c++ designation. Another great video.

Hi Andreas! I learned a lot from you. Thank you for elevating us to the top 1%!

Andreas, thanks for this very comprehensive introductory tutorial. Your subject / explanation style is excellent.

Andreas!!! Lovely video as *ALWAYS!!* After this video you TRIGGERED me to wish that you eventually make a C++ video for Raspberry Pico, please!!!!!!! Thank you for all your hard work.

Awesome video!!! I put a button between ground and PIN run in pico. Now I can connect and disconnect using it

Great tip with the baton, I don't remember reading about it in the book. Thank you Andreas! I also had some issues with threading: it simply did not work when I used VS Code and rshell - but it started to work when I installed Thonny.

There are few things that warms my heart like a peacefully snoring sleeping cat 💕

Thanks Andreas, very timely and very useful tutorial. Another reason to look forward to the weekend!

Ok that's the most adorable snoring cat on the internet. I will become a Patreon now just so you can give her more treats.

Two comments. After I got my pico last month I did a lot of testing with multicore in Python. Globals do get updated across cores. But it’s non-blocking and (other than @ entry) takes about 1 ms so you should use a blocking mechanism if you’re counting on a variable getting updated. Locks, otoh, can be counted on to be updated in real time on both sides. They are probably using an interrupt to do this so you may take a small performance hit when using locks. About the connector: usb-micro connectors are rated for a minimum of 10,000 careful insertion cycles. Detach from the pico side, not from the computer side. It’s way easier to replace a $4 pico than a USB port on your laptop :) I really enjoy your videos, thanks!

Two 32-bit core running at 1330 x faster than the Apollo 15bit guidance computer. 1960s Apollo engineer: what are you using this awesome power for? Maker: I make LED go on and off! Apollo engineer: wtf 🙄

Grear and informative video, thank you! I have just got my r-pico so I will reproduce the interrupt test you showed in both C++ and python :)

The reset pin is the pin 30, is labeled "run", pull it down for reset.

Such a nice, informative, and well-produced video. Thanks a lot.

Excellent! Regarding the RP "reset", I grabbed an old powered USB hub with a switch and inserted it between the Pico and computer.

Great as always Andreas. I do have to say I really dislike the use of interpreted languages(python) on embedded systems since it is such a waste of processing power compared to compiled languages(C/C++). It does however open up the world to people that would otherwise not be able use these products at all. I have worked with RTOSs for over 30 years and remember people getting fired for using blocking functions such as delay loops, sleep, pause, etc instead of interrupts/message queues. Nice to see you re-introducing this concept to the next generation.

Thanks, very useful video. I especially like the footage of your sleepy lab assistant at the end

I like the remark about the 5 cents :) By the way, it's always a plaisure to learn something new with your videos.

Amazing as always! Thank you. Kisses to your cat from my cat!

Yet Another Gem (YAG for short) thank you Andreas for this, I love the comparison in boards and language.

Hello from India Andreas... Thank you very much for all the interesting and easy to understand videos... Please make more videos using Pi-Pico and Python.

Thanks for digging up all this info. Good prep video while waiting my first picos to arrive any day.

A video about uasyncio/asyncio for (single core) multitasking would also be useful to many users in my opinion.

Great! I have just got an LPC55S69 which also has two cores. I am planning to make a quadcopter flight controller with the feature. Your video makes my idea clearer and more valid.

Twist: now that we have watched the video as all pico users do, we are no more in the 99% club. Because Andreas educated *all* pico users. The 99% already know about interrupts, two cores etc 😎 Hurry up if you want to be in the 1%-range (for a second).

Brilliant, just what I wanted to know but could not work out from the documentation or the Forum. Thank you.

This is a great presentation. Lots of good information to use when I can get my hands on a supply of these boards. The only ones currently available in the US are from scalpers charging 3 times or more than companies taking back orders. Perhaps I'll just have to suck it up and wait until March 17 when legitimate orders are fulfilled at a reasonable price. I think there will be a version at some point with WIFI and Blue Tooth to compete with the Esp-32 if the price is comparable. I hope you have a great day.

waiting for your RTOS videos!

Great job with the video as always 👍 Thanks for sharing your knowledge to all of us 👍😊

Fantastic video again. You are a few steps ahead of me, I will get to the 1% soon :). I am testing using the PI Pico as a robotics motor controller with motor encoder monitoring. I could get it to track encoder pulses from an irq up to around 16KHz but was measuring encoder pulses per x amount of time (Using the Timer function in micropython so don't need to calculate time since last pulse), so the code I had in the irq callback was simpler, just a increment of count. Because I want to track two motors for a robotic platform the threading will be useful, hopefully I can run the irq callbacks on separate threads without them impacting the IRQ responsiveness.

i'm a subscriber of your channel for long time ago and i want you know: your content is always the best, regards from brazil

You can add your own reset button on the 'run' pin (pin #30 on the Pico). If that pin is connected to ground the Pico will reset. This will be even more needed once you start with C/C++ on the Pico, as updating the code will require a mount/upload/unmount cycle.

Totally agree with you on the reset button lol. Ran in to that exact same issue when playing around with the cores.

The weekend I was looking into C++ programming of the Pico and found your example interesting for quick testing a project. C++ is a total overkill for 99% of most projects. But industrial applications may be time critical.

Thanks for this, it's exactly what I happened to be looking for. I was trying to find something to do with the 5 Pico's I impulse purchased. Now with some Hall effect sensors and this new found task and interrupt info I think I'm off to the races. Cheers! Oh and the cat snoring at the end is just... awww.. :)

Hey, just as a head's up to people using the ESP-32 and Micropython, while many versions of the ESP-32 are dual core, Micropython only runs on one of them and reserves the other to perform peripheral tasks such as managing wifi without it interrupting the main micropython core. This is true even if you are creating multiple threads! So be aware that even though you're getting true preemptive multitasking in multiple threads, all of those threads still run on a single core. For evidence, look in the ports/esp32/mpthreadport.c and you'll see that all tasks/threads are bound to the same MP_TASK_COREID constant.

We respect you Sir a lot. 👍expecting more experimental tutorials from your side 🙏

Agreed, a reset button is important on any board that will go through many development cycles. It's not just about resetting when it locks up, but also about watching what happens when it is powered up. Yes, there are ways of doing it by button, but 5p extra for a reset button is something I'd happily pay. That said, leave the button off but put pads on the board for me to add it.

To all who want a Reset-Button, I used this technique. I have a Pushbutton connected to the RPi-Pico Pins: PIN No. 30 (RUN) And PIN 28 (GND) -> Any GND will do It works like Charm, no plugin/-out. In Thonny You need only to Press the "STOP"-Button, to notify Thonny about a Reset.

Excellent video and loved to see you cat in the end!

Hey Andreas I love your videos, always with interesting information, and thanks for add spanish subtitles, It allows me to share your videos with my studends. Greetings from México

Pico reset: you wire the GND and RUN pins together and add an extra momentary contact button to your breadboard. Pushing the button will reset the board.

Thank you for alerting me to the Pi Pico. What a useful device for mains powered motor control. I can have one core monitor the mains and set some variables whilst the other one manages the amount of chop the motor gets. Also £4 for an MCU on a board is really cheap.

Great! You've answered 2 of my main pressing questions which are the use of 2 cores and interrupt response time. Disappointed with Micropython slow interrupt response time. I think I'll will wait for the official Arduino IDE support. Hopefully the existing libraries will work as well. Planning to port my application to Pi Pico for more processing power. Currently running on Arduino Uno.

Come now... we can have a reset "button" by soldering a small jumper to one of the castellated grounds, and just tap the Reset pin. Bonus: If things get too boring, Dishka can start bopping the wire around. 😁 Thanks for the video! Glad to see uPython supports threads on the Pico, even if only in a limited fashion.

Thanks for your video! I'm also very interested in the PIO speed, but have no Pico to measure myself. I guess you could build a simple pin-> pin latency test the following way: - Set up a DMA channel to copy the same byte into the IO-space to change the pin (there are different bit manipulation functions at offsets, like set, reset, toggle) - use the PIO to kick the DMA - Maybe you need a second DMA channel or DMA channel chaining to keep the whole engine running

Como siempre, señor Andreas, un vídeo muy bueno y muy buena su explicación. Aún no he podido conseguir la placa Pico pero después de ver este vídeo, tengo aún más ganas!

Excellent, very well explained. You have another subscriber.

This is a great video. You make it sound so simple but I believe you did a lot of hard work to get it done to this level. On a side note, I think that its best we call release() function after accuire() just to release the batton. Just an idea.

Very detailed and a lot covered - thanks Now... designers that don't believe in a reset button do need to have a serious head examination. I designed a PC modem in the 1990s - used a DSP single chip with a controller 8048. The DSP worked great - until it "fell over" - There was no "begin again" control line. The short term solution - power cycle. The fix - scrap the design and go with another DSP design. (One that did have a reset line.) Thanks for the video!

What is the issue with the RESET? Since you're already connecting external components to it, you might as well add a tactile button between GND and pin 30 (confusingly called RUN) to reset the chip.

Great video as always Andreas, you made this look quite simple! May I ask you to raise the volume of the audio a bit? Thanks!

Thank you Andreas, I have been looking for these topics on the Pi Pico and now you provided them in a excellent manner. This is great stuff! Now I only have to find out how to use the Pi Pico as an I2C slave device. I can easily find info on how to use it as master, but nothing on how to use it as a slave. Could you be persuaded to look into this, I think it will be highly appreciated by many people using the Pi Pico:-)

one important note, we can use the two cores OF PICO on arduinoIDE earlephilhower's board by simply calling void setup1() and void loop1() .

Just fantastic again Andreas! Thank you!

Can't wait for raspberry pi pico Wireless version

Thank you for sharing this global variable 'trick'. That "local variable referenced before assignment" error almost drove me crazy :D

This is super helpful. I might use C++ instead for my project if the SNES clock/latch pin is too fast for my project. I hope so, because then i might be able to get away with using 0 shift registers instead of 2 per emulated controller

Yes, not designing in a reset button IS a beginner's mistake. It is also one that the RPi people have not learned from since the very first Raspberry.

Nice ...you have the Rasta colors on your lights :)

Looks like the RUN pin is actually the reset input. Use a push to make switch on this pin to ground to reset. Has an internal pull up. First time I've ever seen a reset pin called RUN.

I made myself a cable with a reset button. Works for every mcu =)

Thanks for the video, Andreas:) PIN30 RUN -> RUN is the RP2040 enable pin, and has an internal (on-chip) pull-up resistor to 3.3V of about ~50K Ohms. To reset RP2040, short this pin low. 2021, Raspberry Pi Pico Datasheet, page 7,8. ... RTFD!;)

I came here for my daily fix of Cute Cat Clips. I wasn't disappointed. Now, where can I find some footage of men with Swiss accents? Oh... wait..

Thanks! a lot has now become clear.

reset/switch button on the usb cable it self - is the way forward, even if it's not the way we are used to

Helpful information

You can surely reset the pico by pulling the RUN pin LOW that reset the pico and its written in the manual

on the pico pi , ctrl D will perform a soft reboot. and if you place a button between Ground and Run pin, it works to program like on the esp8266 and the 32.

This implementation of the _thread module is specific for the RP2040. In the ESP32 it works differently. The second core is not used there. Then you assume that automatic memory locking is implemented between threads. However, the documentation states explicitly there is no GIL (Global Interpreter Lock) used. Which means that bad things can happen with shared access to objects. It is probably safe to read objects written by the other thread, but mutual writes, deletes etc might give surprises. For interrupts there may be restrictions too. Documentation is a bit sparse in that area. On ESP32 you typically use micropython.schedule() to get out of interrupt mode and continue processing in normal mode. Still need to check how they did this for the rp2 port.

I was a bit startled to discover that the Pico not only lacks a reset button, but it uses a MicroUSB connector. Both of these are... bold choices.

It's not this time that you will find the Saint Andreas Fault, Das ist ganz perfekt!

Clocking an ASYNC counter works best for the frequency counters. PIC's for example have nice async counters. I've created counters that handle hundreds of megahertz with pre counters and the async counters with no visible jitter. That was ages ago.

You can add a reset button (shop.pimoroni.com/products/captain-resetti-pico-reset-button), or simply wire a button between the GND & RUN yourself.

Now, to get a Pi Pico so I can officially be in the 99% group by experimenting with the information from this video. I am shocked I haven't picked up 5-10 of them already! Great video, well documented and explained. I will reference it when the Pi Pico arrives.

Another great informative video. I'm a bit torn whether to bother with the Pico or not. There seems to be so much hype over it at the moment with what seems like every man and his dog, (or cat) going over it. All great stuff of course. The Arduino has served us well for years now and with Expressive’s ESP8266 & ESP32 I cannot really see any advantages to using a Pico. I suppose as time goes by there will be something to lift it above the rest. The cost sounds great, in the UK at £3.60, but no one seems to include the shipping during their rave about the Pico, here in the UK the shipping is £2.99, which brings the total to £6.59, that is way over the top I believe. I just paid less than half that for an ESP32 including (now the new tax) and delivery which took just 12 days. It would have been great if they had included built-in WiFi on the chip that surely would have made it more competitive. Although I am probably at the bottom end of the maker pile, it doesn’t appeal to me other than maybe to get one just to play with, same as I did the Seeeduino XIAO. I just hope that all the great makers that post how-to’s don’t abandon the Arduino’s and ESP’s. Dishka is such a great companion to have with you in your workshop!

The baton is like a "token "which is used on databuses, it the token=taken then everything else has to wait.

Great video and you get a nice cat mindful moment as well😀

To reset you don't have to unplug the micro USB connector, but also the other side of the cable OR just use a micro usb cable with a switch.

Wow, this video is great, I'll check out your other ones.

Your professional approach just made the two cores act like a single core. The problem with locks is called deadlock, where the key or keys are not released and the thread process dies. If you want the software to safe all passing of variables needs to be atomic, as in a single atomic particle. If you have to read, modify and write to global variable you would place a lock around it so three actions become the same as one atomic action. So the variable cant be changed by another thread while its being worked on. With deadlocks the reset may be your only friend.

Great stuff!That cat is giving me a good idea though, sleeping sounds great!

There is a good tutorial somewhere I read the other day that takes you through the steps of adding your own reset button...

You can use the existing button as a restart button 99 percent of the time. This will save the USB socket and cost not even 5 cents. We need to add the code to do it of course. A reset button is not a good idea on a lot of professional products and the Pico is also designed as a component for low volume products. Or use a hub with a switch, or add a reset button to your breadboard.

How to Add an Reset Button: All you need to do is to wire the GND and RUN pins together and add an extra momentary contact button to your breadboard. Pushing the button will reset the board.

FWIW, my sparkfun thing plus rp2040 just arrived and I’ve come to appreciate the inclusion of a reset button. :)