4 ms·

You can get little USB power meters but they only tell you voltage and current, not transfer capability. Actual cable testers cost thousands.

charcircuit 4y ago
>Actual cable testers cost thousands. Why? Surely there could be some SBC or something for like $100 which you could connect to your computer. The testing software can measure how long it takes to transfer a file. Then it could try charging itself from the computer requesting a higher and higher wattage. I don't see how a device like that could be so expensive.
- mikewhy 4y ago
  So that measures transfer speeds, but what about the rest of the things USB carries? Here's an example of the data that cable testers can give you: https://m.youtube.com/watch?v=XFbJD6RE4EY https://m.youtube.com/watch?v=XFbJD6RE4EY
  - charcircuit 4y ago
    The goal is to determine the type of cable. Testing the signal quality is an entirely different thing.
    - sdenton4 4y ago
      It would be helpful if the connectors for the different cables had different shapes, so it would be immediately obvious what kind of cable it is and mostly prevent plugging incompatible cables into the wrong places. Thank you for listening to my TED talk.
      - jimmydorry 4y ago
        Thanks to "helpful" legislation, everything must use the same port. Expect this to only make the situation worse in the coming years.
    - _adamb 4y ago
      Yeah, I would like a test device that could let me know which transfer rates a cable supports. I've got a huge pile of USBC cables (and adapters). A good chunk of them might even be USB 2.0! It seems like a device capable of acting as a host & device could just try to shove data down a cable and see what the max is...
      - newaccount74 4y ago
        On the Mac, there's a simple way to check cables: Take a USB3 device, plug it in with the cable, and then go to System Profiler (Apple Menu -> About this Mac -> System Profiler). Look for the device, and check the speed. If it says 480MB/s it's a USB 2 cable, if it says 5GB/s, 10GB/s or 20GB/s then it's a USB3 cable. I assume there's a way to do the same thing on Windows and Linux.
        hanche 4y ago
        I just tested that, and it works. Using a Samsung T7 SSD. Clever. Now I wonder if a similar trick works for power capabilities?
        voltagex_ 4y ago
        There's $50-200USD USB PD meters on AliExpress. I like Ruideng / RD-Tech brand ones.
        newaccount74 4y ago
        Coconut battery shows how much power your battery is charging with. I've only used this to compare power supplies, but I don't see why it shouldn't work with cables as well. Of course that only works when the battery is empty enough to actually fast charge.
- eyegor 4y ago
  I mean sure, but you can't see signal quality at 1gb/s without a scope capable of much higher rates (you need at least a few points in each period). Short of muxing together several fpgas and hand picking components, you straight up can't see the signals. There's a reason why you can buy a 4 digit multimeter for $30, 5 for maybe $500, and >5 costs thousands.

charcircuit 4y ago

>Actual cable testers cost thousands. Why? Surely there could be some SBC or something for like $100 which you could connect to your computer. The testing software can measure how long it takes to transfer a file. Then it could try charging itself from the computer requesting a higher and higher wattage. I don't see how a device like that could be so expensive.

mikewhy 4y ago
So that measures transfer speeds, but what about the rest of the things USB carries? Here's an example of the data that cable testers can give you: https://m.youtube.com/watch?v=XFbJD6RE4EY https://m.youtube.com/watch?v=XFbJD6RE4EY
- charcircuit 4y ago
  The goal is to determine the type of cable. Testing the signal quality is an entirely different thing.
  - sdenton4 4y ago
    It would be helpful if the connectors for the different cables had different shapes, so it would be immediately obvious what kind of cable it is and mostly prevent plugging incompatible cables into the wrong places. Thank you for listening to my TED talk.
    - jimmydorry 4y ago
      Thanks to "helpful" legislation, everything must use the same port. Expect this to only make the situation worse in the coming years.
  - _adamb 4y ago
    Yeah, I would like a test device that could let me know which transfer rates a cable supports. I've got a huge pile of USBC cables (and adapters). A good chunk of them might even be USB 2.0! It seems like a device capable of acting as a host & device could just try to shove data down a cable and see what the max is...
    - newaccount74 4y ago
      On the Mac, there's a simple way to check cables: Take a USB3 device, plug it in with the cable, and then go to System Profiler (Apple Menu -> About this Mac -> System Profiler). Look for the device, and check the speed. If it says 480MB/s it's a USB 2 cable, if it says 5GB/s, 10GB/s or 20GB/s then it's a USB3 cable. I assume there's a way to do the same thing on Windows and Linux.
      - hanche 4y ago
        I just tested that, and it works. Using a Samsung T7 SSD. Clever. Now I wonder if a similar trick works for power capabilities?
        voltagex_ 4y ago
        There's $50-200USD USB PD meters on AliExpress. I like Ruideng / RD-Tech brand ones.
        newaccount74 4y ago
        Coconut battery shows how much power your battery is charging with. I've only used this to compare power supplies, but I don't see why it shouldn't work with cables as well. Of course that only works when the battery is empty enough to actually fast charge.
eyegor 4y ago
I mean sure, but you can't see signal quality at 1gb/s without a scope capable of much higher rates (you need at least a few points in each period). Short of muxing together several fpgas and hand picking components, you straight up can't see the signals. There's a reason why you can buy a 4 digit multimeter for $30, 5 for maybe $500, and >5 costs thousands.