Over the weekend I was finally able to work on my startup/shutdown procedure. It works perfectly, except for two things:
- The power lights stay lit on my USB devices even though I'm killing the power to the hub. One of these devices is a Verizon AirCard, so I'm sure that one is actually pulling some juice from the laptop battery. I'm not terribly worried about the others because they should be relatively passive when the PC is not on. This happens whether I put the laptop in standby or hibernate it.
- When the laptop resumes (from standby or hibernate) it recognizes new USB devices and does the stupid XP ding sound three or four times. This wreaks havoc on my com ports and screws up my touch screen and GPS ports, rendering my touchscreen useless.
I have one theory, that I welcome criticism on. It could be possible that since I'm killing power on my USB hub instantly when the ignition is turned off (via relay - powered by remote wire from deck) this could be "unplugging" the USB devices. Then, when the PC is brought out of hibernation or standby, it finds the devices that were previously unplugged.
If this is the case (which I'm pretty sure it is) how could I keep the power on the USB devices for the required 10 seconds for the lappy to shutdown, but no longer (without buying a high dollar power supply)?
I can't force a standby from RR prior to the power being cut because then it wouldn't wake back up from WOL (due to the connection still being present when it was put into standby).
Please let me know your thoughts.
That's a great idea, but none that I'm aware of. As soon as I open the door everything is turned off. That's the same time it kills the power to the DC power supply since I have it wired to the deck's remote wire.
this can be a problem with any PC that has several usb peripherals with hibernating or standby enabled. sometimes it can help if you re power these usb things before you re power the PC, other times certain things just will not recover from being in this situation & it can be necessary to unplug & replug these devices.
one good rule of thumb is to treat each individually, for example 3 out of 5 things may recover without issue, you can then work on a solution for the remaining items.
I find that sometimes with stuff like gps or touch screens that are acting up, a simple delay circuit can be built, what this will do is simulate a restart without the usb item present, then, when the PC has recovered these item(s) will come back on line & the computer will see them as being just inserted, it can then load drivers & communicate the way it should, if everything comes back on at the same time communication can be disrupted which causes the problems to begin with.
another thing that can be a good idea is to just wire in a "break" for problem usb devices, basically a momentary switch that opens the power line to the affected usb device temporarily when pressed, this will act like a reset for the device & is the equivalent of unplugging & replugging the device.
in the end I guess these are more of a work around than a solution, but sometimes a workaround can be a good solution to
You could rig up a relay that is powered by the USB bus itself so that when the computer is on, the relay is closed and supplying power to the HUB. When the computer is off, the power on the USB goes away causing the relay to open and disconnect the hub. This would make it so that your hub would stay active as long as the computer is on.
Well, I ended up buying a little timer from a local radio shop. It is adjustable from 0 to 100 seconds. I wired it to where it powers the USB hubs immediately after the circuit is opened. This does exactly what I wanted it to do, but frustratingly this does not solve any of my problem. Everything is still unplugged when it goes in standby. Ordinarily I like the plug and play features of XP, but this time it's biting me in the rear.
Instead of using a hub can you run multiple USB cables back to the PC?
But, to answer your question, I probably could run another cable to the PC from the Xenarc, but I don't think that's necessarily my problem. It seems that just the process of resuming from standby or hibernate is causing the problem. What I really want to do is disable the whole "plug and play" feature of XP. That way I could force all of the peripherals to use the same com port as they did prior to restart. Any ideas on whether this would work or if it's even possible?
I don't know, but this isn't the first time I've heard of hub problems after resuming. I'm running 3 USB cables, 2 to a PCMCIA card to avoid hubs.