What is a pullup resistor and how is it used to create a data line?

แชร์
ฝัง
  • เผยแพร่เมื่อ 11 ก.ย. 2024
  • matrix.to/#/#rossmannrepair:matrix.org
    Let's get Right to Repair passed! gofund.me/1cba...
    We repair Macbook logic boards: rossmanngroup....
    👉 DISCORD chat server: matrix.to/#/#rossmannrepair:matrix.org
    👉 Rossmann Repair Group Inc is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com
    ✖ Buying on eBay? Support us while you shop! www.rossmanngr...

ความคิดเห็น • 29

  • @DigGil3
    @DigGil3 7 ปีที่แล้ว +23

    In case you care (and judging by the marking on the schematics), the "talking" from the circuit in this demonstration is using the I2C protocol (protocol means "the rules the emitting and receiving machines agree on to understand each other"; "the language" in a sense). If you want to learn to decrypt this talking (and other protocols used in microcontrollers), I suggest these articles:
    learn.sparkfun.com/tutorials/i2c
    Thumbs up, if you read so far, to keep this info floating on top!

    • @mrsemifixit
      @mrsemifixit 7 ปีที่แล้ว

      DigGil3 So how does (in the video example) the SMC know when to ground the rail the pull up resistor is connected to? In other words how does a circuit know when to pulse a line down to 0v (low) to create data. Is it being triggered by another chip?

    • @franklinmirandadossantos8315
      @franklinmirandadossantos8315 6 ปีที่แล้ว +1

      it's all especified on the i2c protocol. it's complicated as fuck, if your goal is only motherboard repair is not worth to learning this shit, it is only for engineering people to understand in order to design circuits.

  • @saurabhbaid664
    @saurabhbaid664 5 ปีที่แล้ว +3

    Hi Louis,
    In the playlist, you need to swap the video 13 and 14 for the right sequence. This is an amazing series of videos. Keep up the work you do. Very few people in the world want to share their knowledge the way you do.

  • @adonaiarruda3634
    @adonaiarruda3634 9 ปีที่แล้ว +3

    Hi Louis, Thanks a lot for the videos. If possible, I suggest for the new videos for you to talk a little bit slower. For the people who watch this Chanel and are not native english language, sometimes is hard to understand some parts of the videos. Congratulations for this serie of videos

  • @Daniel86
    @Daniel86 9 ปีที่แล้ว +3

    Very good theoretical and practical explanation of how this circuit works, in a way that I enjoy very much, no stupid and boring academical shit, just the basics, and other boring stuff are left for the viewer's brain to solve and understand it if they want to. This is the reason that I am watching your videos, no bullshit, just the real thing, plus some sneaky advises which every technician should have in mind ;) Keep it up, greetings from Macedonia :)

  • @paultidwell8799
    @paultidwell8799 ปีที่แล้ว

    I made it this far! can't wait to finish!

  • @TonyToneFixMyPhone
    @TonyToneFixMyPhone 9 ปีที่แล้ว +2

    Thank you!

  • @NJgoesCrypto
    @NJgoesCrypto 8 ปีที่แล้ว +2

    You amazing man, we need more off your amazingnesssss ;)

  • @PhuketMyMac
    @PhuketMyMac 9 ปีที่แล้ว +1

    Thanks again Louis!

  • @theBoogymang
    @theBoogymang 7 ปีที่แล้ว +2

    Wouldn't they be pull down resistors since they're pulling the main supply to ground to create a signal? Pull ups would pull from ground to voltage level

    • @zot1849
      @zot1849 5 ปีที่แล้ว +1

      that's also what I thought

    • @VeritasEtAequitas
      @VeritasEtAequitas 2 ปีที่แล้ว

      Same thing, different direction. Like conventional vs actual currents it's all relative.

  • @alexcipriani6003
    @alexcipriani6003 3 ปีที่แล้ว

    it’s using PWM (pulse width modulation )which is the ration of high to low signal

    • @roopi67
      @roopi67 2 ปีที่แล้ว

      It's a standard protocol called I2C (look it up), that's why there's references to SDA and SCL (Serial Data and Serial Clock) . PWM is used to digitally control the speed of motors or brightness of LEDs efficiently (amongst other things), it's not a communication protocol

    • @alexcipriani6003
      @alexcipriani6003 2 ปีที่แล้ว

      @@roopi67 I know what I2C is I don’t remember what PWM was in response to

    • @roopi67
      @roopi67 2 ปีที่แล้ว

      @@alexcipriani6003 I'm responding to your above quote "it's using PWM..." , you don't see it?

    • @roopi67
      @roopi67 2 ปีที่แล้ว

      I checked your channel and yes I expect you will know what what I2C is, interesting projects 🙂

    • @alexcipriani6003
      @alexcipriani6003 2 ปีที่แล้ว

      @@roopi67 I see it! I don’t remember what my “it’s using PWM” referred to…what “it”

  • @ytrew9717
    @ytrew9717 5 ปีที่แล้ว

    Hey Louis, there is a mistake in your yt list "Guide to basic electronics; unprofessional..." : 14 goes before 13 (according to what you say at the beginning of your video). Please correct this.

  • @zsoltpalko101
    @zsoltpalko101 9 ปีที่แล้ว

    Hi!
    Maybe a noob question, but someone can have the same thought:
    Let's say my hardware test says that PCH temperature is out of range, that causes maximum CPU load and fan raving.
    A checked schematics and PDF for PCH, but no temperature output is used for PCH on the A1465 Air board. Wild guess, but does it work so, that every component - PCH, trackpad, CPU, etc… has only one double output(CLK, data) for data transfer for the SMC? Can this line include more, than one information about the device? So the schematics SMBus Connections table shows every connections that go to the SMC for diagnostic (Voltage, amperage, temperature) measurements?
    In my problem, means that i have to check the pull-up resistor and the voltage that makes it logical high? I don't need the direct answer for my problem, just wan to understand the how-to of the logical lines in Apple boards.
    Zsolt

  • @SevenDeMagnus
    @SevenDeMagnus 9 ปีที่แล้ว

    Hi. I'm guessing but I I believe It's 0 and 1 with 0 as low power and 1 as high power as seen on the scope (the binary in 0 is not really zero volts but low power coz' there's no way for the OS and prog), then that combination of 0s and 1s processed in the embedded program/software in the IC which shoots linearly at the moment the pulses of electrons as low power (0) or high power (1) which the iOS or OS X interprets then relay as graphics (alphanumeric is a graphic like hieroglyphics only it's popular that we all can understand it, much like the oscilloscope represents it as a waveform graphic) to determine the amount of charge and I guess rpm for the fans and temp. With the OS knowing before hand what the full charge of that particular battery is and makes it calculation base on the voltage drop. If it doesn't know it, it can' calculate properly and we see that usually when there's an anomaly, like when you use lithium batteries on the Magic Mouse or Apple's keyboard, it doesn't show it accurately coz' it only knows Alkaline at most I'm guessing.

    • @binness
      @binness 8 ปีที่แล้ว

      Why are people answering the question of what it is by saying it is ones and zeroes, that is obvious and Louis knows it, the question is what is it saying not how is it saying it, and by the way you don't need to know in order to trouble shoot, if this is the best guess you can come up with, then do not apply for a job with Louis, keep on trucking.

  • @tomarjannikov6649
    @tomarjannikov6649 7 ปีที่แล้ว +1

    If you want to decode the communication, you could use a logic analyzer, like www.saleae.com/

  • @pajeet7966
    @pajeet7966 3 ปีที่แล้ว

    You did not explain how come it does not short the whole machine when the data line goes from 3.7V to 0V. You said it's because there is that 2.61K resistor but that does not make any sense at all.

  • @muddshshshark
    @muddshshshark 8 ปีที่แล้ว +2

    100-100-1 SOS
    100-100-1 IN DISTRESS
    Trying to change its program
    Trying to change the mode...
    crack the code
    Images conflicting into data overload.