06-30-2016, 09:25 AM
(This post was last modified: 06-30-2016, 09:38 AM by Oscar.)
(06-30-2016, 09:07 AM)MarkHaysHarris777 Wrote: (06-30-2016, 08:53 AM)Oscar Wrote: (06-30-2016, 07:54 AM)MarkHaysHarris777 Wrote: The K70 is probably sensitive to being hot-plugged. If you open it up you'll probably find it has (1) chip. ... and it probably isn't well protected. More likely than not hot-plugging the keyboard is what damaged it. The other possibility is ESD; which also has the potential for damaging any uncased board like the PineA64, or the Raspberry PI... for that matter.
But two things: 1) plugging a $120 keyboard into an open SBC is insane; and 2) blaming keyboard damage on the engineering efforst of the Pine team is no fair, especially without proper testing nor corroboration.
1) plugging in a USB complaint device into a USB compliant socket [is] not insane ... Well that is the $120 dollar question isn't it? I'm from the old school, and 'we' never hot-plug anything (not ever) and 'we' have not had anything damaged as a result either... I have a very inexpensive wireless keyboard (usb receiver) that I use with my Pine and PIs. I change the receiver only with the power off. I would never plug a $120 dollar keyboard into a PI, nor the PineA64. IMHO its insane to treat a $120 keyboard that way... and the proof is in the pudding, isn't it... his keyboard IS damaged (one way or the other) so, it was insane, wasn't it?
Compliant, non compliant, meh. If you value your equipment, you will not hot-plug it... ever.... physics does not understand compliance...
 I too am "old school" starting out on various microcomputers and electronics since 1980 before professionally building/maintaining/repairing DEC minis and peripherals all to discrete component level before slumming it with PC since '95.
I have provided remote diagnosis professionally and I would say the OP did not provide sufficient information to say anything other than the title was his opinion. Perhaps I missed something, if so please post the evidence in this thread that you based your opinion upon.
also
http://www.silabs.com/Support%20Document...erview.pdf
http://www.farnell.com/datasheets/1650952.pdf
and specifically
Hot pluggable/Automatic configuration – Enumeration (which we will get into detail later) enables a device to
be plugged in and its operating parameters communicated to the host. Also, the USB spec takes into account
inrush currents for devices that are going to draw their power from the bus.
(06-30-2016, 09:25 AM)Oscar Wrote: Hot pluggable/Automatic configuration – Enumeration (which we will get into detail later) enables a device to
be plugged in and its operating parameters communicated to the host. Also, the USB spec takes into account
inrush currents for devices that are going to draw their power from the bus.
Over and over... you guys are missing the point... the keyboard IS damaged, so none of the above matters, does it?
If you want to hot-plug your equpment (you trust the protection schemes, against physics) well then you go right ahead and do that... not me.
I only hot-plug cheap stuff. My $5.00 USB keyboard and cheap mouse etc....Anything I cant easily replace or is expensive gets plugged in or out only with power off. I do the same thing with USB thumb drives. If the information is valuable and losing it would cause issues I don't unplug it with the power on, even if I have used the software ejection tool.
With that said, it COULD be coincidence, maybe something on the keyboard was getting ready to fail and it failed at the moment you plugged it into the Pine. Maybe the failure occurred unplugging it from the original computer. A cursory google search leads to many cases of this keyboard failing. It doesn't mean the Pine didn't kill the keyboard, only that with the information given it is impossible to tell.
06-30-2016, 01:14 PM
(This post was last modified: 06-30-2016, 08:32 PM by DonFL.)
I must be living right, or incredibly lucky. While I typically don't hot-plug on a hobby board (pi, pine, arduino, etc), I've never ran into a problem with typical pc type stuff. For usb drives, I'll use the software eject tool and remove.
All that said, we've taken this thread into the ditch and exa (the OP) has to be wondering why he even asked. He's been called insane and lectured on hot-plugging, that sure doesn't encourage one to bring issues to the group.
Will be interested in knowing if he confirmed his pine is working fine, and, if he's definitely sure the K70 is dead, or whether he was able to revive it. That keyboard has some interesting stuff going on, with a usb hub built in, couple different usb cable configs, etc. https://delightlylinux.wordpress.com/201...and-linux/
I appreciate this discussion about hot plugging USB devices, I have never thought about it. I would NEVER hot plug an HDMI cable, but never thought plugging and unplugging a USB device, Guess I am lucky. But as often as I swap remote receivers in and out of my Android boxes, I will continue doing it without powering off the devices.
(06-30-2016, 10:40 AM)MarkHaysHarris777 Wrote: (06-30-2016, 09:25 AM)Oscar Wrote: Hot pluggable/Automatic configuration – Enumeration (which we will get into detail later) enables a device to
be plugged in and its operating parameters communicated to the host. Also, the USB spec takes into account
inrush currents for devices that are going to draw their power from the bus.
Over and over... you guys are missing the point... the keyboard IS damaged, so none of the above matters, does it?
If you want to hot-plug your equpment (you trust the protection schemes, against physics) well then you go right ahead and do that... not me.
But then you mightn't feel it heating up and have that 1 in a million chance of ripping it out before the magic smoke is released!!!
Indeed, the point is there is a dead keyboard here... now what is needed is the find out the cause... was it poor design / a fault of the keyboard, or a fault on the pine64s part? I'm inclined to think the fault lies with the keyboard, especially if it is anything like my G510s keyboard (which btw has this ridiculously warm spot in the middle of the board underneath... really... on a keyboard?????).
It is really up to the OP to do some diagnostics in order to try and work out what caused what, and if the keyboard is dead.Plug a power meter into the usb outputs and check if they are in spec (5v on the outer power pins, and no nasty voltages on the data pins). If so, it was just bad luck, and unfortunate, and could probably just as easily happened when plugging the keyboard into any other device. How dead is the keyboard really?... and is it really dead or is the USB plug dodgy... I thought a USB capture card had failed the other week as nothing would pick it up, and not even a kernel message from linux. Then when plugging it in one last time, saw the power light flash on... and realised the USB connector wasn't making contact properly... poped it into a extension cable half-way (to keep the tension on the contacts), and it works again! So it isn't always as straight-forward as going 'I plugged it in and it doesn't work... it's broken'! 
Haha, the hot-swap discussion continues.
For what it's worth, I plug and unplug USB stuff all the time. It seems silly to me to shut down a computer just to insert a USB flash drive, I thought USB was all about hot-swapability? As usual though, things are a little deeper than they appear on the surface.
By the way, I think the OP has long since left the building....
Some More fuel for the Fire. USB is designed to be hot pluggable
https://en.m.wikipedia.org/wiki/USB
(07-01-2016, 01:38 AM)Boring Wrote: Some More fuel for the Fire. USB is designed to be hot pluggable
https://en.m.wikipedia.org/wiki/USB
Oh no... make it stop!!!! 
Yes, indeed it is... it is at the heart of its design. Even to the point where on the USB connector the outer two rails are slightly longer and closer to the front than the middle two, so that the power lines make contact before the data pins do, so that device has a chance to start powering up before the data pins connect.
However, we could do a song and dance all year about wheither we should hot swap stuff or not... and none of us would necessarily be right. I hotswap stuff all the time - be it PC stuff (USB, hot swappable SATA), micro-controller stuff (arduino, STM32, raspberry pi, chip), etc.... and don't think I've ever had anything fail that way that wouldn't have failed if I had powered it down first and then connected it. I even plug my laptop into the mains power whilst it's running... that counts doesn't it? lol Then again, I generally have plenty of protection ;D (current limiting supplies, appropriate fuses, some idea wth I'm doing!)... but that isn't to say that powering stuff down first isn't a good idea... prevents ESD, intermittent connections and power spikes... but that just isn't for me!
07-01-2016, 09:20 AM
(This post was last modified: 07-01-2016, 09:36 AM by Oscar.)
Electrically USB supports hot plugging but most operating system use caching so USB data storage appears faster this by redirecting reads to the USB storage device to the cache. If the most recent data is still in the cache then the cache returns the result and read stops there. Writes to, data still pending, can be written to the cache instead resulting a massive increase in access speed but is comes with a hidden cost.
Caching acts like a temporary ramdisk and has an inherant flaw, namely that the OS shows that data writes have completed before all cached data has actually been written to the USB device, thus if you remove the device before the cache is empty then not all the data is written resulting in, what the OS sees as, data loss and formatting errors.
Again the need to unplug/eject USB media is the Operating System's need rather than the USB's, the later is quite happy if you remove a device half way through writing, it didn't lie about what data was written, it was the OS that lied.
Since USB is designed to be hot pluggable and only a problem with storage devices because of the OS lying about write completions then by rights you should be able to plug and unplug a normally keyboard for instance as many times as you like, assuming both manufacturers have kept to the USB standard then there should be no problems.
The OP had a device which had been working fine, it failed when it was plugged into his pine, many things could have gone wrong and we as outsiders cannot legitimately have any opinion about why it failed given the information available from the OP. The OP who I would say is not competent (surmised from what he did post) to make the decision that the pine caused his keyboard to fail made a statement based upon belief as well and I read his post as such.
We all, I presume, want to be helpful but posting mere opinion as fact cannot be seen as being helpful, presenting your faith as evidence doesn't make it convincing. I say faith because unless you understand the why of something based upon facts then your mantra of protection is just that a belief, one I now hope has now changed into an understanding based upon facts instead.
I do not like to be pedantic but I have noticed that one poster here and across the forum is quick ( in IMHO ) to post his opinion (to often based purely upon faith) as being fact and, I would say, that posts of this type are no help at all. It may be a problem of translation between brain and keyboard but I would ask that person to think first and check twice what he has written before hitting post. If it is just an opinion then make that clear by including "I think", "I believe", "in my opinion", "in my experience" etc otherwise you are annoying people because you are countering their statements based upon faith alone when this is not a religious forum.
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