overcurrent charge - did I brick my arduino?

when I plug in my arduino into my Linux box, I get the followin in the syslog:

Dec 26 19:37:17 tomodachi hub 1-0:1.0: over-current change on port 5
Dec 26 19:37:22 tomodachi hub 4-0:1.0: over-current change on port 1
Dec 26 19:37:22 tomodachi hub 1-0:1.0: over-current change on port 5
Dec 26 19:37:24 tomodachi hub 1-0:1.0: connect-debounce failed, port 5 disabled

and no related USB-serial device appears. previously this all worked fine. does this mean that I have created a nice, little, life-less brick from my arduino?

Akos

that just sounds like your computer disconnected Arduino from the USB bus because it thinks Arduino is drawing too much current... try a different USB port, some are only meant for low current, especially keyboard USB ports.

that just sounds like your computer disconnected Arduino from the USB bus because it thinks Arduino is drawing too much current... try a different USB port, some are only meant for low current, especially keyboard USB ports.

as I wrote above - it did work from that very USB port before - so it's not that that specific USB port couldn't handle it.

but, doing more experiments, it seems that the arduino broke my USB port :frowning: this 'change' happened as I was working with the arduino, and at some point it wouldn't respond through the USB anymore. now, if I plug anything into the port it tells me the same, be that a mouse, whatever. it just doesn't work anymore. if I plug the arduino or something else into other ports USB ports on the same machine (there are 3 on this laptop), they work fine.

this is quite a bad result - killing a USB plug on my laptop. I only have 2 to go. is there a totally safe way to connect the arduino to my laptop? maybe through a USB hub?

Akos

I haven't seen anything in the forum about buring out USB ports by plugging an Arduino in.. but a quick google search of "over-current change on port" comes up with 15 pages of results for that exact phrase, mostly about hardware-linux conflicts... have a look, it would be much more llikely that Linux is shutting down the port for some reason than that the Arduino had damaged it.

I haven't seen anything in the foums about buring out USB ports by plugging an Arduino in.. but a quick google search of "over-current change on port" comes up with 15 pages of results for that exact phrase, mostly about hardware-linux conflicts... have a look, it would be much more llikely that Linux is shutting down the port for some reason than that the Arduino had damaged it.

I don't know how I could convince you that the USB port was totally operational for 2.5 years until yesterday, with the arduino and with other other devices as well. and it turned un-operational when I was working on the arduino plugged into it. there seems to be a clear causality effect going on here.

I see you didn't hear about anything of this sort, but I'd much rather have some hard facts about what an ardunio can or would send back on the USB line, even in the face of heavy mis-use on the board itself. I have had the assumption that it would block all harmful stuff towards the USB device. I'm not sure anymore. actually, I'm convinced about the contrary now.

the question is - what is a really safe way of plugging the arduino into a USB port, so that it won't damage it for sure.

OK, on the assumption that your usb port is burned, the only thing I can think of is that the actual pins of the Arduino USB connector (the ones under the pcb that are exposed) could have been shorted out at some point when you were using it-- i.e. they might have touched a resistor sitting on the table or something. A dead short of the USB 5V supply would do different things to different computers, but I am guessing that most have built-in usb controllers tha monitor the current source and shut it down when there's a short.

Massimo or David C, two of the developers, can probably jump in and give you some advice here. For my part, I haven't seen this kind of thing before. I have taught more than a hundred students how to use Arduino in the past year, using every kind of laptop imaginable, with no burned USB ports. The library where I teach lends out 50 Arduino's continuously, and no one has reported a burned port... but there is always of course time for a first!
Try messaging massimo or David C or mellis if they don't respond to your post, as they will have a definitive answer on where to look for a solution.

Try booting from a Linux live CD, like Knoppix or D*** Small Linux or similar, and see if the USB port still works or not.

No definite answer here, but I assume a USB hub will protect your laptop since it has its own built in power supply, and the USB signals will go through some microcontroller before being forwarded to your computer. So I assume IF some shorting occurs with your arduino the silicon in your hub should be fried first and protect your laptop's USB ports. Hopefully.

Hej,

I have never burnt a USB port so far. My experience is that the Arduino board kills the chip before the port gets affected. However, I had a similar weird problem during a presentation at a conference. I plugged a total of 21 Arduino boards using hubs to my laptop. On the other side I had a processing patch reading data like crazy and representing the multiple inputs on a bidimentional interface.

The thing worked fine in the tests, but I suffered the world famous demo effect. And my USB ports stopped working for a while. And when I say for a while, I mean completely and for about a week. Then, the same way they left me, they came back. I was running XP and had only 3 USB port in my laptop.

I vote for the OS blocking a port as the most likely thing to happen to you right now.

Regards,

/David

The thing worked fine in the tests, but I suffered the world famous demo effect. And my USB ports stopped working for a while. And when I say for a while, I mean completely and for about a week. Then, the same way they left me, they came back. I was running XP and had only 3 USB port in my laptop.

Strange - I didn't think of my machine as a self-healing entity so far..

I vote for the OS blocking a port as the most likely thing to happen to you right now.

well, I don't know, looks more like a hardware issue to me.

anyway, as one can't change the past, I'm more interested in findig out how to connect the arduino in a way that will not have adverse effects on the laptop, for sure. as we spoke about a USB hub earlier - would that be enough? does it have to be a self-powered USB hub?

actually it is possible for the port to be 'self healing', believe it or not! This is from the offical specification for USB 2.0.. note the "polymeric PTC's", which are resetable 'self-healing' fuses.

"The host and all self-powered hubs must implement over-current protection for safety reasons, and the hub must
have a way to detect the over-current condition and report it to the USB software. Should the aggregate current
drawn by a gang of downstream facing ports exceed a preset value, the over-current protection circuit removes
or reduces power from all affected downstream facing ports. The over-current condition is reported through the
hub to Host Controller, as described in Section 11.12.5. ...

If an over-current condition occurs on any port,
subsequent operation of the USB is not guaranteed, and once the condition is removed, it may be necessary to
reinitialize the bus as would be done upon power-up. The over-current limiting mechanism must be
resettable without user mechanical intervention. Polymeric PTCs and solid-state switches are examples of
methods, which can be used for over-current limiting."

(p. 173 Universal Serial Bus Specification Revision 2.0 )

PS: If you are really worried about burning a USB port, you could build a cable with a 1A fuse/PCT in series with the 5V supply: just break open a USB cable and solder it in series with the +5V line. I've never seen a cable like this though, since the official spec as above requires this inside the machine. Or, just use a powered hub between the arduino and the laptop-- one that has the spec'd overcurrent protection.

actually it is possible for the port to be 'self healing', believe it or not! This is from the offical specification for USB 2.0.. note the "polymeric PTC's", which are resetable 'self-healing' fuses.

thanks for the information. I don't suppose it would take a week for such a polymetric PTC to 'heal' itself. these specs are amazing, I'd just hope they would be implemented as well :slight_smile:

PS: If you are really worried about burning a USB port, you could build a cable with a 1A fuse/PCT in series with the 5V supply: just break open a USB cable and solder it in series with the +5V line. I've never seen a cable like this though, since the official spec as above requires this inside the machine. Or, just use a powered hub between the arduino and the laptop-- one that has the spec'd overcurrent protection.

probably this will the the next step, that I look for such a HUB

thanks for all the information...