Neat And Tidy USB-C Conversions For Legacy Devices

USB-C has been on the market for a good few years now, and it’s finally starting to take over. Many new laptops only come with the newer port, making it difficult to use legacy USB-A devices. [Matt] doesn’t like mucking about with dongles and hubs, so set about converting some older hardware to the new standard. (Video, embedded below.)

[Matt] first set about hacking a Logitech wireless mouse dongle, peeling apart the original USB A connector to gain access to the PCB inside. A USB C breakout board is then sourced, and the relevant pins in the USB-C connector are soldered to the original USB-A connector pads. Unfortunately, the breakout board is configured as a host device, unsuitable for peripherals. Replacing a pull-up resistor with a pull-down on the VCONN and CC1 pins rectifies this. With the mod done, the mouse enumerates and is fully functional over USB-C. A little Sugru is then used to wrap everything up neatly.

[Matt] then progresses through several other similar mods to other hardware, sharing useful tips on how to make things as neat and useful as possible. It’s a tidy hack that could make your user experience with a new laptop much less painful. USB-C mods are becoming more common, and we’ve seen plenty done to soldering irons thanks to the Power Delivery spec.

42 thoughts on “Neat And Tidy USB-C Conversions For Legacy Devices

    1. They do, I got one last year or maybe even the year before on Aliexpress! So yeah they exist since a long time.

      What we are lacking in my opinion are small female USB C breakout boards. There are many different ones on Aliexpress but they are not very small and I didn’t see any that comes already with resistors to configure them as USB 2.

      1. In the video he lops a resistor off the connector, and it appears that there’s an unpopulated spot adjacent to the resistor he removed. I wonder if he’d just moved it over would it have reconfigured the connector.

        1. At 7:04 in the video when he says “Looking closely at the board.”, you can see that the traces going to R2 connect to GND and the other end of R1. So, yes, I’m fairly certain you are correct about the wiring. But the legacy host adapter resistor values are different for the host and device, so the surface mount resistor that is populated should be 56KOhms while he needed a 5.1KOhm for the pulldown. So maybe he didn’t have a surface mount part with a usable value. He definitely should have added more detail about the configuration pins are used to negotiate, as it is easy to get wrong and might apply up to 20V to Vbus 0_0

        2. I also was hoping for a bit clearer explanation of the resistor configuration. I accidentally tore a micro USB connector off a board and was planning on replacing it with one of these Aliexpress USB-C breakout boards. I’ll need to track down some documentation myself about the resistor configuration I guess.

  1. I need exactly the opposite because I don’t have a single USB-C device and no intention to buy them on purpose either
    On solution could be to buy a few USB-C to USB-A adapters, glue them in your laptop and you don’t have to care about adapters or losing them anymore.

    1. Agreed. If some new laptops are only coming with usbc, it would be a reasonable reason to avoid them. Too much common peripherals ( keyboards, mice, usb drives ) are not usbc. Some small adapters that could be glued to the laptop could be a good solution.
      Maybe some 90 degree ones, so that they do not extend too much out of the laptop outline.

        1. USB-C has been around for years. One of the earliest smartphones to use the connector was the Nexus 5X/6P. That was 5 years ago now. There was a transition period. Aside from a keyboard/mouse that still works, there aren’t many types of devices that are USB-A only (and more of those devices implement connectivity over Bluetooth or WiFi than ever before).

          1. I have at least 17 USB 2.0 and 3.0 flash drives and an assortment of USB 2.0 and 3.0 hard drives. Not tossing out all of that to replace them with USB-C versions.

    2. Why are people so stubborn over technology? This will let you daisy chain 4k displays and hard drives on a single cable with a hard drive sitting at the end. Saturating the drive will have no effect on the displays and vice versa. It’s really interesting.

      1. The connector lacks the robustness of USB-A, and is a lint and grime magnet on even laptops, and on smartphones it’s even worse.
        The intentions are pure, but the execution is lacking.
        And much of what you mentioned is specifically displayport/new HDMI or thunderbolt, sometimes it’s best to keep things K.I.S.S

        1. “Lack the robustness” I’ve seen more destroyed USB-A ports than I have USB-C for several reasons:
          USB-A is big enough for small humans to stick their fingers in
          Its also big enough to shove a penny in the pin side
          Its non-reversible plug also makes it really easy for an angry or uncaring person to demolish a port by forcing a plug in backwards.

          With USB-C, you have a port that is:
          compact, reversible, durable, cleanable, and extremely versatile.

      2. Also, the alternate modes and multiple power standards mean we’re back to having cables that we don’t know will work. The nice thing about USB previously was that you could guarantee compatibility. USB-C and M.2 remind me of the old DB-25 ports. Is it serial? is it parallel? is it SCSI? Guess by the gender of the port, and try it out, maybe it will work.

        1. BTW here is a fun chart for different length USB C cables:

          So if you want to standardize your set of cables to USB 3.1 Gen2, you might find out that they are limited to 1m. (A long cable would degrade the higher speed signals more than it would for slower speeds.)

          If you really NEED a longer one to connect the wall wart, you now have two types of cables (gen1, gen2 or USB 2.0) that works on a different speed. Sometime, you might get a USB2.0 bundled from a device because the manufacturer decided to cut cost on cable. USB 2.0 subset has less wires means less labor assembling the cables.

  2. The problem is USB-C will never completely replace USB-A…. USB-C is a replacement for USB-microb and esata basically…

    They should have modified USB-A to support all the same pins as USB-C and kept the more robust connector as the host end.

    1. USB Type-C will completely replace all other USB Type, including Type A… More and more Motherboard came with PC included with 1 or 2 Type-C or Thunderbolt 3 (USB Type C & TB3 use the same connector)…

      Manufacturer love to use smaller usb connector that can do more than the old USB Type A… But for now its still pricey…

      In the next 10 years, USB Type-C will completely dominate all electronic device that still need cable….

      1. USB C cable will remain pricey as the assembly is done by hand and they take far too long to make one. (I read they can make 4-5 cables per hour)

        This is the problem with a tiny connector that are not designed for easy assembly.

        1. And anything but a basic USB 3.1 cable requires a controller in each end.
          Which has already confused plenty.
          Also adapter/dongle gate.

          Imagining USB C to THE connector standard is naive, like trying to solve the problem of 14 standards and ending up with the problem of 15 instead.

  3. I’d not recommend extending the life of Unifying receivers, unless you like the idea of people injecting keystrokes into your computer. See MouseJacking and LOGITacker attacks.
    But other than that, very neatly done! great idea!

  4. The biggest problems with USB still aren’t solved with USB-C: Data is required for charging functionality beyond snail pace, meaning you leave devices open to hacking. And the data functionality means that I can’t plug my USB-C hub into my phone to charge it, as the negotiation makes the phone go “Nope nope nope” and it reboots.

  5. My question would be that I expect that the hardware might be brought up to USB type C except for, perhaps, speed and Alternate modes. For example, Thunderbolt and Displayport at the currrent rev. can be run up to 10 GBs. Can the hardware of type A be brought up to “speed” on this? I expect not. Also, Displayport or Thunderbolt Alternate mode for transferring high speed video is probably requires a firmware update to the USB controller hardware, which may or may not exist for that particular controller.

    I am not attempting to be pedantic here at all. It is just that I have a requirement for a smart glasses embedded camera which requires the hardware to be Displayport 3.1 Type C alternate mode compliant. I do not have such a device and a retrofit, if possible, would be a great help to me if one existed.

    Thank You

  6. I am planning to connect a “dumb” strong battery to a Lenovoe Laptop with usb C charging port, but i like ot avoid using complicated modules. THe battery supplies 19V which should be good to charge the laptop or at least alov som extended operating time. The question is, if i can cheat the laptop with a correct resistor value to pretend the battery is a 20V/5 Amp source.
    Does anyone has tried hacks in this direction already?
    Any tips and tricks are greatly appreciated.

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