4 ms·
unless the connector were cut, or some other catastrophic failure. I tend to think ruining a devices USB controller should be near impossible short of something
by earlz 11y ago
unless the connector were cut, or some other catastrophic failure. I tend to think ruining a devices USB controller should be near impossible short of something like the USB killer (http://arstechnica.com/security/2015/10/usb-killer-flash-drive-can-fry-your-computers-innards-in-seconds/ http://arstechnica.com/security/2015/10/usb-killer-flash-dri...)
- lucaspiller 11y agoI was playing with a FTDI (a clone :D) and an Arduino and accidentally mixed up VCC and GND from an external power source. I only realised because Minicom was failing to connect to the device. Then I realised what I had done, I tried removing it from the USB port and putting it back in, but it wouldn't work. I then tried a mouse too, but that wasn't working either. Thinking I'd killed a USB port on my Mac (well there are two, so...) I then tried rebooting and that fortunately fixed it.
- earlz 11y agoYep, did almost exactly this, shorted a converted 3.3V from a different USB port (same machine) to ground on a different USB port and end result is my motherboard lost all USB connectivity until I rebooted
- nerfhammer 11y agothe usb ports on macs are supposed to have overcurrent protection. You actually get a dialog popup in the OS when it happens. I know because I've triggered it doing something with an arduino.
- klodolph 11y agoUSB overcurrent protection is pretty sophisticated. Devices get 100 mA for free, then have to ask the host for more current. Well, it's a bit more complex nowadays, but that's the basics.
- rcxdude 11y agoI'm not sure if there are many devices which actally follow that spec to the letter (in either direction). Usually the USB ports will just allow 500mA (or whatever they're designed to provide) plus some fairly generous overhead, regardless of what the device has asked for, and assuming they bother to implement overcurrent detection at all.
- nerfhammer 11y agoI believe macs give you 500ma for free
- bsder 11y agoUse ... a ... hub. If you're doing lab work, it's really easy to get weird potentials on various lines. I almost never plug anything like an Arduino directly into my laptop without a powered hub in between. I assume I'm a klutz. So, I take steps to minimize the damage when something happens.
- totalart9000 11y agoAnyone have a hub to recommend? I have a hub which I bought for cheap on eBay which I use on my desk for keyboard, mouse and similar but would not trust that hub to offer much if any in way of voltage protection so I'd like to know about safe hubs for lab use.
- bsder 11y agoJust about any externally powered hub is fine. As long as you're plugged into the wall, it's going to help dramatically if something stupid happens. Personally, I've switched over to using USB 3.0 hubs. They supply more power and seem to be better built.