Mister Barnett, I must say that I've never heard the concept of pull up / down resistors explained so clearly and concisely. Very well done. You have given me an idea on how to build an alarm system to see if anyone has opened a door or window remotely and to activate a video recorder to stream the output to my smart phone. Now all I have to do is to figure out the streaming bit to my phone. Thanks.

YT is pure gold as long there are people like you explaining stuff.

That might be the simplest and clearest explanation of pull -up and -down resistors I've come across.

Wow, wow, wow, just wow. I'm blown away by how clearly, thoroughly, and yet concisely you are able to teach. I probably gave you a thumbs-up when I first watched this video, but as I watch it again for review 5+ years later, I'm just blown away by how great of a job you did on this one. Thank you!!

Best explanation I've seen yet. I was seeing those terms like "pull-up/down" in the kits I was working with and struggled with understanding the problems and risks.

Heh, Thank you, I never truely knew what floating was in my undergrad, I just knew the pins had to have a pull up or pull down to complete the circuit. I never thought of the protection! You explained it with a circuit and that I can understand. Thank you.

This tutorial rocks. Thanks! GPIO wasn't too clear to me, but now I "Get it" ... Thanks again... great videos!

Thank you. I'm fairly proficient with Arduino's and electronics. I've been looking for some straight-forward examples of using the Raspberry Pi as I would like to harness more powerful boards. Many videos waste lots of time talking about irrelevant things; you've cut straight to some actual examples and it's absolutely brilliant. Subscribed!

Have to do a bit of microcontroller engineering at work and this video is a relieving primer -- thank you for this crisp exposition.

Thanks for this excellent tutorial. While I'm a competent programmer, any discrete electronics knowledge I had fell out of my head 10+ years ago - this was perfect to give me everything I need to actually get back into it.

it's a shame to say that, as a student who just started learning python, i did not understand well during my class. But watching your lesson helped me a lot ! Thank you so much!

I like your teaching method of suggesting the simplest solution and patching its shortcomings, like what you do for pull-up/down. Very effective. Good work!

Your enthusiasm is contagious, I wish I'd had an I.T. teacher like you at school!

Glad I decided to bingewatch your videos on SPC's, I was just about to mess with buttons and GPIO on my ESP8266 and I had never heard of pull up and pull down resistors. Great explanation for electrobics noobs!

just this year I heard about this raspberry pi, it has been hanging around for years already. I'm glad that there still free video like this to learn. Thank you.

This is brilliant, thanks for the guide! As you say, all sorts of projects could be derived from these!

Pure information - invaluable in today's world. Extremely clear, concise, excellent productions. Kudos.Thanks

You are simply the best at explaining. Thank you.

thank you for such a simple and comprehensive tutorial, which helps new comers understand basics that aren't found easily

I like how you show a variety of circuit diagrams to help understand

Christopher Barnatt is a Good KZfaqr... Explains in detail...

Another great video! I recently completed a school A-level project using a raspberry pi, and your videos were, and still are a valuable resource to me when making that project! Your videos are so easy to understand, and basically taught me the more useful stuff a pi can do, so, thanks a bunch for the great videos!

I just received my Rasberry Pi 3 Model B the other day there so look forward to watching your tutorials on YT. Thanks!

Thank you - this is exactly the kind of Pi video I needed to see. I'll be jolly glad to see anything more on the Pi. You set the standard that others can only follow. I wish you a great week.

This is a great video thank you! I think I was just as stoked about the open and close when it scrolled on screen as you were! Computers rule!

Thanks for this. I've been a an electronics hobbyist for months. This is the first clear explanation of why and how a pull up/down resistor is used. Tons of videos where they say they're using them. So few explanations as to why or how they worked (what they do and why to use them), I was starting to wonder if they were different kinds of resistors. Very clear video. Thanks again.

amazing job. Only video I've seen that actually explains the how and why bits in simple terms. Very high quality content; exactly what I needed to understand GPIO. Great teacher, and great skills. Subscribed.

I don't know if that's clay dough or play dough, but it's ingenious. I have stuff sliding all over my laminated desktop, and sometimes falling off the edge and going overboard. Sometimes I use rubber feet help to keep things from moving around while I work. So now I need to find out what that stuff is, find some that's non-conducting, and "dough down" all the electronics I have sliding all over my desk. And getting that Raspberry Pi 4B to work was a virtual nightmare. Neither of the two monitors I bought for this project would work with the MicroHDMI-to-VGA converters I bought. So when I first booted it up, I saw bits and pieces of boot-up stuff, but after boot seq., I got two blank screens. That was with Ubuntu Desktop, after I burned-off 5GB of bandwidth (I only get 30GB per month). I figured the download might be rotten, so I burned-off another 3GB of data using the Raspberry Pi Imager - which I no longer like. The problem with the Raspi Pi Imager is that you can't really store the download - it just downloads it and burns the MicroHD card. If anything goes wrong, you lose your download and whatever bandwidth you spent on it. You can copy the card, but you need a clean one for that, and I have Windows data on all of my spares. I also still have the 128GB SD Card from the Raspberry Pi 3B+ I still have, but for all that trouble, I'm not going to blow out that (working) OS. In the end, I tried another monitor and it worked. And then I found a second monitor off of another computer that worked. The two I bought for this project still work on other computers (with VGA output), but not on this machine. So that's really odd. I don't use Python - I use C or C++, so this is a nice video but I think I going to have to download some pre-made software that gives me access to the GPIO ports. I'm especially interested in the SPI ports, as you know, but there may or may not be software already written for this computer. SPI communications are not only data, but timing signals (clocks) that have to be synchronized with the data. I'm not sure how the computer does this, since it's usually done in the hardware. I can only hope that the BCM2711 has it built-in (for all six ports).

Another great Raspberry Pi video. It's interesting to see the sorts of projects you could make with the GPIO pins.

Fantastic video! I too have never been really able to understand what and how the pull up and pull down do and work. I appreciate your tip on the safety current limiting resistor going into the GPIO pin. I like your coding work as well. You have eloquently explained this... Thanks again for your excellent video! More Raspberry pi project videos like this one please.

Breadboarding, hardware and logic, good stuff. Thanks

You are one of the most helpful teachers in youtube! Thanks!

Wow, how is nobody commenting on the sheer size of this man's read switch!?

This is the best raspberry site I have ever seen! Please keep it up! very well explained and in the appropriate English language! Thank you

Very useful info! I'm going to use it to make a sleep tracker.

Hats off to you man for precisely describing everything. Works for one of my problem quite easily. (y)

this video is very help full for engineer or student ,thanks

Oh wow.. This is so awesome! Please continue this type of explaining of builds. Without anyone next to me in normal class to ask questions of. This is by far the next best thing. I wish I could hit a subscribe on you tube to send money for your great efforts. You have not set with in KZfaq.

Great video, well explained with a good coverage of the electronics and why to add resistors as well as what the phython code does, Excellent.

Thank you very much! Very clear explanation on great ideas to have a computer respond to real world events.

Good Video, nice combination of circuit theory, actual wiring and enough software to get it going.

I really enjoy watching your videos. Very detailed and easy to understand. I really would like if you can make a video of how to connect a Pi to an Arduino through the serial port and talk to each other. I have been watching a bunch of them but none of them are very clear to understand. Thanks

Liked the way you explained .... made things easy to understand . Thanks for the vedio

Nice job. The explanation and graphic are very easy to understand.

Incase someone hates pythons, does not convinced why it even exists. Can just tryout gpio CLI. The code used in the video, can be done with simple shell script: gpio mode 16 in while do r="$(gpio read 16)" if [ $r="0" ] then echo "open" else echo "closed" fi done // Don't worry about clean up, it just sets all pins to 'in' mode // pk fython I like this video though

you're becoming a hero now....

You are great thanks for all the great work you do, I had to recommend this site you developed to family.

I have not done anything like this...ever, and it literally looks like rocket science.

Love the way you explain everything.. I hope you plan on doing more Tutorial, examples..

Great presentation style, well explained and easy to,follow

Great video! that's what I call a great class where efficiency and ease of learning meet. In a few minutes you really explained everthing I needed to know without wasting time. Thanks!!!

Thank you for the video. I have learnt a lot and will be trying this out. I am still enjoying your videos and hope to carry on enjoying them.

This breadboard must be at least 1000 years old :D Thanks for the video.

This is the best tutorial for IoT I met.

You know that you don't need sudo anymore to control the GPIO ports right? Excellent tutorial, I wish you did this when I started 2+ years ago :)

Thank you! I've already done a kit from Adeept but did not know about Idle, I've been using Vim or sudo and haven't been thrilled as I prefer some for of gui for highlighting certain things.

Positively brilliant tutorial and instruction. Your educational skills are masterful. Thank you for sharing your knowledge, and skills. Technical mastery and compassion incarnate. Thank you, Mister Barnett!

Thank you for making this! I have a recommendation. Please consider spreading out your components on the breadboard so that the fixed camera view and less intuitive viewers (me) can clearly see the inline resistor a couple of cm away before it splits into grounding-resistor and switched-3.3V

That explanation about circuits was amazing.

Thanks for another awesome video, I generally like your videos, andI love your videos on GPIO. Keep up the good work.

Chris, I love your videos and am working my way through all of them. May I suggest that the schematic drawing of the breadboard connections is confusing. I think you should explain how the "squares" are connected for those who are not familiar with breadboards. I.e., each vertical columns of squares on the extreme left and right are electrically connected together, while each horizontal rows of squares (excluding the extreme left and right squares) are connected together.

This is a good video is easy to understand GPIO works for newbie like me ..

good health and long life to you, thanks for sharing soo much with the world .

Your tutorial rocks. But all of the Raspberry Pi GPIO pins have internal pull-up or pull-down resistors that can be controlled from code.

the pure torture of it all Chris is that I have to wait until the first to get my check... dang and I thought I learned patients as a lad... well I guess it is learn and learn again eh? this is all too exciting..

Fantastic channel. Thanks and kind regards, Mark

Thank you very much, this video helped me greatly, I’ve subscribed and I am excited to watch more of your videos

Best tutorial I've seen! You explain things in a very methodical and clear way at a good pace. I am not new to electronics, just to the Raspberry Pi. I have started with Raspien and am using Thonny IDE. I see you prefer a different coding window, is it simply a command line? Do you prefer it to the Thonny? Thanks for making such outstanding tutorials.

finally i understand the keyword finally.. i was already wondering when i saw it in java code haha

Love these videos... Excelent explanation.

Thank you Christopher. You explain well.

I know this a old Post but really trying to loop the (push button) back to run again and again every time script is finished . Just can't find away to run program by push button over and over.. Thanks for all your knowledge you have given this channel is alsome.

Excellent tutorial

Thanks so much i got my relay working it was an active low (god i hate AL all relays should be AH instead lmao but i got there in the end :)

Its really a useful and very good video enjoyed keep it up

great video, thank you for taking the time to make it

Awesome. Loved this little tutorial

Very nice and good video instruction.

Excellent demonstration!

Great video! Very informative! Keep up the good work!

Thank you very much, I learned a lot from this video.

amazing. really love how you share your experience :). I'm happy to learn from you.

Play with it for hours! lol That had me on the floor lol

Thank you! Very simple, but also very helpful.

hope to see some LCD or 7 segment output then keypad in the next tutorial

Excellent Explanation! Well done.

Your videos are excellent, subscribed

Thanks for this.

Thank you so much for this beautiful explain

The 1k resistor to the board-pin makes sense almost no matter what. What would happen with the print statements (I mean the final output) if you had omitted the 10k resistor to the ground? Would it still work in some cases but not in others? What would I need to check / know to ascertain whether I need to put a resistor ?

Wondering if you can have 'on conditions' or event handlers like you can in environments like, say, Javascript/Web. That might be more convenient than having to write polling loops all the time.

Chris, is that your voice in the EC theme song? I'm going to have to watch this 400 times to understand how to put this together without damage to the SBC. Dang! But it is practical, useful and interesting. I'd like to see more like this. Really would. No offense meant about your singing.

Great video, but you don't need to run the program with sudo(8), if you add the user to the right group. Have not my RPi near to check which group is needed. Running program as root with sudo is usually a bad idea. I would also use a variable or named constant instead of using 16 in the program. It will help you to use the right value, and not the wrong by mistake. You should have mentioned debouncing when reading from a switch in the first program. The switch could bounce and give you some fast on-off readings. Except for that, great video, and I like the resistors protecting the input.

LOL at your comments! Way to keep the critics happy...

Love these videos. Thanks!

Nice pack of information! thanks.

Nice video. In looking at your implementation of the circuit it seems that the green wire should be connected to the same node that connects the two resistors. In the configuration shown, the GPIO pin is connected directly to Vcc through the switch.

Imagine that we have made in the eighties storage controllers with much less evolved hardware just like this 😄

This is very good.

Thanks a lot for your great explanations and for your work