A USB-PD Laptop Conversion In Extreme Detail.

With USB-PD slowly making wall wart power supplies obsolete and becoming the do-it-all standard for DC power, it’s a popular conversion to slap an off-the-shelf USB-PD module in place of the barrel jack in a laptop. Not when it comes to [jakobnator] though, who fitted his Dell with an upgrade lovingly and expertly crafted for both electrical and mechanical perfection.

The video that you can find below the break is a long and detailed one, but in that detail lies touches that set the conversion apart from the norm. We’re treated to a full-run-down of USB-PD module design and chip programming, and then the mechanics of the 1-wire chip through which the Dell ties itself in with only Dell power supplies. Programming this chip in particular is something of a challenge.

It’s the mechanical design that sets this one apart. He started with an odd-shaped space that had contained the barrel jack socket and a ferrite choke, and designed a PCB to fit it exactly. 3D-printing a model to check for fit is attention to detail at the stratospheric level. The result is a fit that looks almost as though it was part of the original manufacture, and which should keep the laptop useful for years to come.

This may be the most elegant USB-C laptop conversion we’ve seen, but it’s not the only one.

Thanks [Jero32] for the tip.

31 thoughts on “A USB-PD Laptop Conversion In Extreme Detail.

      1. After the new mess with latest revisions of USB-3 and the USB-C ports regarding standards and modes, I’d unironically agree.

        USB has essentially become the enemy is was supposed to defeat.

        1. “One connector many incompatible protocol.”
          We have at least 10 “set of capabilities” already.
          One device can charge via usb-c, the other cant, others can do only that.
          One outputs displayport on it, the other don’t, others output only that.
          One has usb3 speeds, the other don’t, others has only that.
          One has thunderbolt, the others don’t.
          One has only usb2, the others have others.

          Its one connector and a huge mess.

          1. You’re missing the beauty of it, it’s one connector that allows any and all of the above functionality. I can charge my phone off my dev board’s usb-c cable or use my phones QC brick to power a USB device.
            Was stupid micro/midi/normal/fuckenbigonefordisksandcrap USB connectors and shitload of different power cables & bricks really so much better?

          2. Ahhhhh, finally, a replacement for the classic 5 pin DIN, it could be audio in/out, MIDI in/out, AV in, AV out, Power in 5/9V, 5/12V or other varieties.

          3. @Robert

            Yes it was better. Why? The average user could cope with it.
            The average user will just see “its usb-c” and tries to plug a random usb-c peripheral/adapter/charger/whatever into it and does not know why it’s not working. For the average user it is impossible to remotely understand what “protocol” and “capability” means. They just see usb-c.
            Also how many device manufacturers list the capabilities of the usb-c port on their device? Almost none. They list if they can use it as a marketing point (like thunderbolt3), but that’s it.

            One of my friend bought a top of the line machine, with two usb-c thunderbolt3 ports. Surprise surprise, it can’t charge from usb-c. This is mentioned nowhere that it can’t charge from those.

            I myself have a thunderbolt3 dock, and even after researching for a week what exact specifications I need for it to work flawlessly I still ordered the wrong one, and if I plug it in my notebook’s CPU throttles from 55W of power budget to 15W. If I unplug it, it works on 25W on battery, and 55W on the original 90W usb-pd (non standard wattage obviously…) charger.

            Oh and the upcoming usb4 just adds more mess to this already messed up situation.

            I can also charge my phone with the same charger as I use for a RPi (/other SBC). A micro usb one. Your point?

            Whoever invented this usb-c “standard”, I hope all of them burns in hell. Should have required that to get a usb certification that the EXACT capabilities are needed to be listed in the product specification. What PD standard does it uses, if it uses one at least how large charger is needed. Is it usb3 or usb3.1 or only usb2.0? Does it support DP alt mode? Etc etc.

          4. What are you talking about, I have a whole lot of USB-C devices and they all work together just fine. I think you are just making up stuff to sound like you know what you are talking about.

          5. I have several docks with various features including video and ethernet. I have several phones and tablets and a whole bunch of chargers. I’m doing all the standard stuff and it all just works. Unlike others I did my homework and checked for compatibility before purchasing. I passed on several items due to the known issues that you apparently ignored.

          6. >it all just works
            >I did my homework
            Good for you. Do you think that the average folk will do the research? They just see a plug that fits.
            Just because you happened to stumble upon a set of compatible devices that does not mean that EVERYONE was this lucky. Boo hoo it works for me should work for everyone else. No.

            As I said my dock (Lenovo Thinkpad Thunderbolt3 Dock Gen2) does not work well with my notebook (MSI Prestige 15). It limits its CPU performance to 1/4th. The notebook has only usb-c as charging option btw. It also does the same on a docking capable usb-c dell monitor.
            Nor does my friend’s Asus Zenbook work with usb-c chargers (dedicated charger or the dock), yet it has two thunderbolt 3.

            Oh, and also just because they write its thunderbolt3, some manufacturers does not wire it up to a pci-e x4 lanes, but only x2 or even x1. Fun times when you discover that its only x2 and you can’t run two 4k monitors from it at 60hz. And where is this mentioned in the specsheet? Nowhere.

        2. That’s what happens with “design by committee”, aka “standards”.

          Ref: the late, [not] lamented Ethernet AUI slide latch connector; mechanically unsuited to the application and a royal PITA.

        3. Yeah it’s terrible. It was so promising but maybe shouldn’t be a surprise since every iteration has been poorly designed to the point it’s questionable whether they had engineers involved at all. It blows my mind that the port is still the weakest link and not the cable, Micro-USB was notorious for failed ports and broken solder joints.

  1. I’m definitely in the NOPE group here in the USB-PD discussion.

    It works perfectly fine in a homogeneous group of smart, well informed, good actors.

    But it breaks down like communism when you let ACTUAL humans have a go at it.

    The very idea that Joe Regular might think it is ok to plug his laptop into a conveniently placed cable because it has a standardized connector and he needs to juice up is horrifying.

      1. That’s funny.
        But no.
        I mean from a security perspective.
        USB power delivery REQUIRES the data pins to function. So there will absolutely be several attacks that use that attack surface. And as this standard becomes more available, and as people get more used to the idea of just plugging their phones/laptops into any available USB-c port, the incentive will only increase.

        1. No, USB PD has two dedicated pins. Of course it is a data interface, but the thing talking to it is usually very embedded, not the main os. So it seems the impact of a vulnerability will be minor, and very device specific.

  2. and the barrel jack…. well I have yet to see one that has failed. Most laptops have internal dc-dc buck converters so are quite flexible as to the supply, what have we gained? Complexity, expense and dubious long term durability. Pfffft But hey jump onto a trend if it suits you…. but, this one just suits the salesmen….

  3. This is my video! So cool that I was featured on hackaday I have been a reader for years and never would have dreamed something I did would be featured. Thank you for writing the article. I was surprised to scroll through my feed and see what looked to be my video and when I realized it was I was so surprised!

    As for the ongoing war for/against the growing USB spec. I think @Robert said it best in that the point of a unified connector is for one plug that can do any of the functions. There is a lot of hate jerking for the USB spec but I don’t think those people understand the point. It is intentional to leaving the different sub-protocols up to the manufacturer for each use case. Although it may confuse users that not all USB devices can use display port or PD charging, I think it’s better than the alternative of a million different connectors or requiring all sub-protocols. If you are upset that a laptop doesn’t allow for display port or PD charging you should take it up with the laptop brand, not the USB committee for not requiring ALL the sub-protocols to work in order to be allowed to use a type C port. This decision would be nuts and drive up costs to low cost electronics and be even harder to get manufactures to adapt to type C.

    Thats not to say the USB spec isn’t without issuesI, the naming convention is a complete mess what the hell were they thinking? Hopefully moving forward thunderbolt 4 will clear things up for consumers.


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