Pull Up/Down Resistors

In hardware projects, you often see resistors used alongside components like pushbuttons and transistors - Why? In this video, we explore this and also consider some possibilities this opens up!

0:00 Introduction
0:28 Floating Pins
1:36 Pull-Down Resistors
3:14 Pull-Up Resistors
4:47 Strong vs Weak Pull
5:41 Conclusion

Some more sources you may be interested in:

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Disclaimer: Please note that any information is provided on this channel in good faith, but I cannot guarantee 100% accuracy / correctness on all content. Contributors to this channel are not to be held responsible for any possible outcomes from your use of the information.

[TynerPesch]

this is by far the the best description of pull up / pull down resistors i’ve come across

[nijoeli]

I was trying to understand pull resistors for a couple of days now, thank you very much for this explanation:D

[Sharmamona]

BEST EXPLANATION

I HAVE A SCHOOL PROJECT RELATED TO UNO

THANK YOU FOR THE HELP!!!

[MrKbtor]

I must have watched a half dozen videos and gone to 2 dozen websites but watching this finally helped me understand. Thanks!

[ousmanediouf]

Underrated
Best video I've seen I guess

[hootsoon]

Very helpful like it read my mind, was about to search this up after hearing pull up and pull down for so long

[RobytheFlorentine]

very good video. Thanks from Florence, Italy

[Srishen]

Great stuff! Would love to see a series on transistor configurations from you!
Love this, godspeed!

[nickstamatiou]

Very nice video. Maybe you could explain how to calculate the resistor value next time. Thank you so much

[vadimc]

Good explanation, man. Thanks. I subscribe.

[Jechew]

This is absolutely the best video on YouTube regarding this topic that I have come across. I do want to ask how I would consider pull down in terms of current, though? Is low to 0 current a logic LOW and vice versa? In that case, would the pull down's job be to induce very low constant current to negate the effects of noise? If it is, then which way is the current going and? Lastly, I wanted to know what the other end of the microcontroller being connected to output=ground is doing in that case? Thanks.

[davegraham]

Hi 0612 tv from N.Z. Nice to see a new video.

[mr.olsen.]

Thank you for the video. I`m building a arduino grbl cnc. I got alot of problems with limit switches, how "big" resistor should i use? Have tryed 10k with no luck.
Thank you.

[swainscheps]

If the wire acts like an antenna…why do random signals flowing between ground and the pin behave differently from the random signals from before (when there was no pull down resistor)? Your animation shows there’s noise on the wire either way. So how does that solve the problem?

And why does the closed switch ‘overwhelm’ the path to ground?

I believe you. I’m sure you’re right. I just would love if one of the 40 YouTube videos on this topic would take a little more time and explain the why.

[OdysseyAviation]

What the red and black points moving in your circuit means. Like I still don’t understand how voltage comes from ground to microcontroller

[ousmanediouf]

4:06 How can current go from ground to voltage ? Shouldn't it have gone from voltage to ground ?