Thank you for your nice words!

I hope so ;-) Thanks for your compliment!

Thank you!

I agree

I was astonished about the reactions on this video. I thought, it is too hardcore for UKposts and expected only a few viewers...

Sometimes I think, my content is too complicated (for example for this video). But then, the feedback seems to be ok...

At least for me it's perfect :-)

Wasn't too complicated at all Andreas, fantastic job explaining it quickly and concisely. I wrote Hackster's article on "Multithreading" an Arduino. I might have to write one for ESP32 now and reference your video!

@@AndreasSpiess No, this is great! Your balance is for me perfect, and with the great advantage (compared to many UKpostsrs) is your stringent editing where you do not waist words/time. Pausing and looping back in a video is so much better than fast forwarding to get past blablabla! I am a proud to be a Patreon supporter, and I just bought you a coffee as a special thank you for this video. (I am finally about to transit from ESP8266 to ESP32, and your videos is the obvious starting point.)

I tried the other way round when I bought my milling machine. It was hard for me ;-)

I also use the ESP8266 for normal jobs, because I still have a few laying around...

Thank you for your feedback. I think, without semaphores, two cores are not very useful ;-)

You are right.

Thank you for the tip!

at 4:42 , isn't that delay(1000) supposed to increase time instead of decreasing it? since the void loop() also is getting exceuted..

@@RakshithPrakash I think that RTOS handles this and does other stuff while the loop is in the delay

@@sasodoma Thats what appears to happen, but it would be better as mentioned above to just stop the loop entirely

Thank you for your nice comment. So far, I am not on Patreon. But this might change if I cross the 50'000 subscribers...

Glad to be able to help.

+Philip Moyer Please come back with your learnings. This is still new technology.

It works! I created a typedef struct definition and instantiated a global scope variable - this is used to transfer data between cores. Core 0 polls an attached SI7021 temperature and humidity sensor, loads the data into the global scope variable, and then delay()s to control the timing. Core 1 reads the data buffer struct, displays the data on an OLED, and then uploads the data to adafruit.io (which is Adafruit's IoT/cloud offering.) Works like a charm! I couldn't have done it without your guidance, though! [Oh, and this is running on the Adafruit ESP32 Feather.]

Thanks for the update. Cool!

Oops. I take that partially back. It works for a while, and then produces nonsense data, and then stops working altogether. Debug time!

+Philip Moyer As I mentioned: I also had some issues to solve....

:-)

:-)

You are welcome!

Thank you!

Thank you! I was not sure when I did the video. The stuff is quite complicated...

Welcome to the channel!

Thank you!

Thank you for your nice words! We will see what we can do with these new possibilities...

Thank you!

Thanks for the feedback! Interesting. So it works!

Yup! I had it running for maybe 30 mins or so and it was working fine (I know not a conclusive test, but promising for sure!)

You are welcome!

Enjoy! I am sure this is a new dimension for Makers...

We will see where these new possibilities lead us...

Glad to be of help. I also learn a lot through UKposts!

I was thinking the same thing. I just got the itch to explore ESP32 bluetooth again and Andreas posted a video the day before!

Luckily the blink delay is different by 200ms, so the increment are never at the same time. But you're right: counter++ should be between the take and give...

I second this; nobody likes to search for those "heisenbugs" that this could lead to.

+Walter Steinchen I know the problem but not the solution in this scenario (how to define protected variables). However I think, using semaphores can be used to prevent a double update. But I am still looking for a definition like "volatile"

Andreas, excellent video, but access to the global variable isn't exactly being controlled by the semaphore. At least not the way the video explains it. In the code it seems more like a side effect rather than proper handling. As long as folks know that more work needs to be done on the subject they can resolve the 'heisenbugs' (I like that name).

+Neil Cherry Msxbe the solution is already there and I only do not know it...

Thank you! We will see where these possibilities lead us...

Never visited your country so far... Maybe I can change that when I stop working. I strongly suggest you try this part of electronics. It enhances the useability of the part you are using now.

You are welcome!

And the Wi-Fi connection opens a whole new world of possibilities...

@@AndreasSpiess wow I'm just imagining that new world 😊 now I just to write my C library of the nrf24l01. But with the ESP modules, the WiFi is built-in so that's more juice. I know it won't be easy to work with the nrf24l01 modules. But the work you do in calibration and testing modules is so much interesting.

Thank you for your feedback!

I definitively would go for the ESP32 if it has enough pins for your application because it is much faster than a Mega and I think, also more memory. And maybe you can remotely control your cube?

IoT LED Cubes! Sounds awesome.

Hari Wiguna be careful if you want to use digitalWrite though - the ESP32 can be slower than the classic Arduino, or at least not as fast as one thinks. I might have learned that in one of Andreas's videos.

afaik our beloved ESP8266 also uses FreeRTOS for its sdk ;-)

The question that comes to mind here is. What am I going to do with all the Arduino boards I have, nano, Uno, Mega.....

I also like this concept of tasks.

Sounds like this project is getting better and better!

We will see if I find the time...

Glad to help!

You are welcome! These are maybe common wishes?

@@AndreasSpiess Yes i think so :)

Thank you for your nice words!

You are welcome!

Thank oyu! But this one is quite old ;-) So it came too early.

I can't wait to see what Expressif's next big thing is ------ ESP 64 maybe ?????? That'd be nice :-)

+Roy: I think, I have enough to do to learn how to work with what we have with the ESP32 ;-)

If I would be a real magician, I probably would not show you the tricks. Would be bad for business ;-)

Andreas Spiess your the best, you show all your apprentices how to wave a magic wand🤗

:-)

You are welcome!

Thank you!

I also discovered this possibility quite late.

Thank you!

You are welcome!

You are welcome!

Thanks for the tip!

I'll second that - in spades. If you really have a good understanding of what you're doing - or can "be the computer(s)" in your head, oftentimes you don't need to block on semaphores or mutexes or even spin-busy on a shared boolean. My outfit wrote quite a bit of "very high 9's" software for some telecom manufs using this trick - and some of it hasn't crashed since started in the 1990s. But! You'd better darn well comment in unmistakable ways "the wires that aren't there because they don't need to be" - why you can do this without all those moving parts. Because someday, someone else is going to touch that code and since it looks easy - will not bother to undertake a full understanding, and that's when your phone rings at 3 am...Of course, that other person might be future you who has forgotten the plan. But it's still worth it - even though they take awhile to type - comments run VERY FAST! They also don't take up a lot of space in the runtime(!).

Another viewer did some testing and wrote, that Wi-Fi runs on core 1. Do you know more?

Thanks for your reply Andreas. No I don't know more. I think you are much more up to date with the ESP32 than I am. I am simply stating the historical basis for the second core and went by what Espressif were saying at the time. I was unaware that the new Arduino interface for the ESP32 was layered on top of RTOS. If the default for WiFi and user-defined are both core 1 then that would kind of defeat the purpose of the second core unless RTOS has already taken the balancing of tasks into account.

Even if on some of my videos our cat appears ;-) Thank you!

Thank you! We will see in the future...

You are right. But for the moment, most of my viewers want to stay with the Arduino IDE. So, we have to take what we get (and create some push on Espressif by using their chips).

Agreed, thank you for sticking with Arduino for these types of things. It is much more accessible than ESP-IDF for now.

I had to reduce the speed in one of my videos. It is possible. I do not know if you can switch a core off. Video #161

Thank you!

You are welcome!

Thanks for your feedback. It is encouraging to see that it works...

Please give me a hint how you did this to solve the same issue... Thanks

Can you be more specific?

Thank you!

Good to know. So far I did not try this route...

I'm thinking about putting a course together that will go over this. I'll keep you posted on my progress

Good to know. Hope it helps!

Good luck with your project. Seems to run not only at the "Leading edge" but probably at the "bleeding edge"...

Thanks for the additional information!

Thank you!

You are welcome!

Thanks. I was not convinced when I published this one because the topic is quite complicated...

Thank you!

You are welcome!

Thank you!

Thank you for your feedback!

I knew it is possible, but not using the Arduino IDE...

Thank you!

Thanks!

You are welcome!

Thanks!

You are welcome!

You are welcome!

Peter S - lol Peter S! I did not expect to find you on this side of the internet! it's funny how we're both interested in politics and electronics 😄 P.S. your profile picture is easy to notice 😂

Hello Daniel, I'm an EE who designs and manufactures building automation gear and I've been a hopeless nerd since the early 1970s. My computing career started on IBM punch-cards which were legacy at the time but still in common useage around Silicon Valley, where I grew up. Previously I was director of engineering for a $200M/yr Macintosh peripheral manufacturer where I was designing and building Thunderbolt II / USB 3.0 RAID enclosures most of the week but that got old because I was working for a hardcore conservative CEO/owner with 200+ conservative employees and had to live in conservative Texas. I am a San Francisco Hippy and Texas is not my thing even if BBQ is some of the best food in the world and their craft beer is amazing. His mother was dying of stage 4 cancer after surviving cancer twice before and I introduced him to the data about cannabis killing cancer cells without harming healthy ones. Her doctors had given up and left her for dead but he confirmed the data I gave him and she started cannabis flower extract oil treatment. She went from terminally ill to cancer free within 18 months and I permanently shook my CEO's faith in conservative thinking. When I quit the guy had removed cannabis from his company drug testing and he supported gay marriage while his wife was still an obvious bigot. He told me he was pissed off that he had been lied to by the people who taught him his conservative values. It took the hopelessness of his mother's mortality for him to finally realize this. His wife even asked him if he was becoming a liberal after I had worked on him for a year. That opened the door for him to start telling other conservative people that they had been programmed by lies and he told me he has since spread his story to well over 100 other medium to large corporate CEO types. I'll also add that I've been a very vocal proponent of medical cannabis for over 20 years with a couple years of tabling at events for TexasNORML where I performed outreach using a large base of peer reviewed data to back my arguments and I am most likely the first person in the Western Hemisphere to put bar codes on retail cannabis which happened at a San Francisco dispensary I wrote the point of sale system for back in 1999. So anyway... now you have a better idea of who I am than 99.9% of the people on the political channels. I'm not a big fan of politics but they affect me and I must do what I can to better all people. I'm far more interested in research concerning the endocannabinoid system, embedded processing, and mountain biking. Best wishes, -Peter

Peter S - Wow, That's an amazing background story :D I really don't have much to tell, I'm a 22 year old guy that has been programing videogames on game maker since I was 13. Graduated from one of the best engineering high-schools in Mexico with my own developed wireless comunication (like Bluetooth) system and then came to the US (legally) to finish my degree. I currently finished developing a text based operating system on my own. Now I'm integrating it into any microcontroller that can handle the code. (an arduino uno or better) The proof of concept is in my smartwatch based on the esp32 (if your interested, I could make a video presenting showing my operating system working and explaining the impact this could have in the WHOLE microcontroller industry). I'm planing to show it at some fancy company and get hired in any development type area. I am struggling to get the first step because I lack of any contacts that can hook me up.

+ Peter S: I am proud of my viewers if I read your story! Thank you for writing it down!

Wow! That's very cool. I started by programming games too. That's an excellent path. The tools these days are so amazing, they allow you to really set your creativity free. My first home computer was an Apple ][ back in 1978 with 16K of RAM and a 1MHz CPU that was over $2000 in 1978 dollars. Now a $10 ESP32 can do so much more that it's almost silly. I am envious of your generation in many ways but I'm also grateful I got to listen to 1980s music as it was being made. Anybody who can design an RF communications system is very impressive to me, as are people who can speak more than one language, so you are doubly impressive. Americans are probably the least linguistically knowledgeable people on Earth so being bilingual is an excellent and valuable skill to many development companies. Developing an operating system is also impressive so make that you are triply impressive. I appreciate your offer of an explanation video however at the moment I am in the middle of designing a system for a client based on 12 different ARM Cortex M4 nodes on CAN-bus and my head is so full that it's leaking so I must decline your offer, but I encourage you to make such videos and place them on UKposts because they can be a very powerful tool for getting a job. I also encourage you to make them several times over a few months like each is practice for the making the next and get feedback from your peers to help with refinement. Most of the time people make documentation only once and it's like the 1st time a musician plays a song, no matter how good it sounds, you know that the 100th time will sound better because of practice. Your 4th video about a subject will typically be far better than the 1st. I pay attention to how creative people are when I hire and my last hire got their job by showing examples of building guitar sound processing circuits she had developed and others she built from designs on the net. Showing examples of what you can build is more powerful than most things you can see written in ink. For most positions I deal with, to me a physical example of something you designed and built is far more powerful than a degree from anywhere. Einstein did not possess a degree in Relativity Theory and he was reportedly a very poor student. There are some positions where a deep education is necessary but most positions from my experience require somebody who is capable and enthusiastic and able to adapt to the needs of the moment rather than somebody with a piece of paper. Once you make it into a development lab, somebody like you will naturally advance so don't worry about entering as a technician as long as the pay is acceptable. I wish you the best and perhaps the best advice I could give you is to be very persistent and get your resume out to lots of potential places because it's a numbers game, but above all make sure you're happy where you work because you cannot buy happiness, you can only generate it.

:-)

Thank you!

Thanks!

You are welcome!

Thank you for the information! Good to know.

:-)

Have fun!

you are welcome!

Bitteschön!

You are welcome!

Welcome aboard the channel!

You are welcome!

You are welcome!

:-)

You are welcome! I am surprised by the number of views. Thought, this is only interesting to a few...

Thank you!

Gracias!

The same happened to me when I discovered that it is possible ;-)

You are welcome!

I am not sure if this concept works for two processors. I know it works for one. But this problem is much easier to solve as you just can prohibit an interrupt for a short time.

Yeah, maybe not. I've got an ESP32 coming in the mail soon that I feel will kick me in the butt trying to fully understand it. I've been on your channel for about an hour watching ESP32 and LoRa videos to study it - keep up the great work Andreas!

Defining variable as 'volatile' is definitely a step in the right direction, but isn't quite the ENTIRE answer. The reasoning behind 'volatile' was more for the purposes of variables that could be altered in either the normal flow of a process, or perhaps in some ISR (Interrupt Service Routine), but this is still on a uniprocessor setup albeit with two distinct 'threads' of operation.. Thus, the 'volatile' definition was / is a 'hint' to the compiler that it should not 'cache' the value of a variable as it could quite possibly change BETWEEN sequential instructions in the normal flow if an interrupt had occurred. What's required is a second step of mutual exclusivity (often called a 'spinlock') that guarantees exclusive access to the variable(s) in question. The goal of a 'spinlock' supercedes ANY other asynchronous event (whether it is an interrupt, or perhaps even an entirely different CPU core), from modifying some fundamentally exclusive piece of data. Concepts such as spinlocks become VITAL when you start developing non-trivial software (eg: The Linux kernel). In the OLD days, much of the Linux kernel revolved around a single HUGE spinlock that was known as the BKL (Big Kernel Lock) which inhibited almost every other possible thread from execution. Now that the kernel has significantly 'matured', the 'granularity' of spinlocks has been significantly improved such that threads are far less likely to be 'blocked' waiting for the release of the BKL from some totally independent mutual exclusion. (Imagine having to 'stall' every single core of your 28 core beast simply because ONE of those cores wanted exclusive access to the UART ringbuffer. That's how it was actually done in 'the good old days')

Glad you like it!