Re: Xo1.5 crashes
On 10/07/2012 10:21 PM, Mikus Grinbergs wrote: IIRC, Richard warned about connecting an XO's USB socket to any USB device where that devices's USB socket can emit power (that sets up a condition where a non-XO device can try to send power to the XO -- which is a no_no). The details are fuzzy but in Kevin's case I believe he was trying to use a external CDROM that drew a lot of juice tying to spin up and fail. To compensate he was connecting one of those rechargeable batteries with a 5V USB output via a Y cable. So now you have 2 power sources fighting it out on the USB bus and the XO-1.5 would lose. So when i plug one usb device into the xo be it an ipod or a cell phone while running on battery the screen goes white and the laptop reboots. It works fine when plugged in charging though. I just wanted to let you all know what im experiencing. I believe the devices are drawing too much current from the laptop and forcing a reboot. It doesnt matter which usb port i plug it into. What production rev model is your 1.5? Did you get it from the developer program? I have a vague recollection that some of our earlier runs of 1.5 had a USB issue like that. -- Richard A. Smith rich...@laptop.org One Laptop per Child ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: Xo1.5 crashes
Since I don't own a cell phone, I've never tried charging from an XO. My external USB storage devices are all self-powered; and my other USB devices (adapters, microscopes, keyboards, etc.) are all low-power devices. In about four years of using XO-1.5s, I haven't ever had the XO-1.5 crash when I dynamically plugged any USB device in. mikus ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: Xo1.5 crashes
On Sun, Oct 7, 2012 at 3:11 PM, Mikus Grinbergs mi...@bga.com wrote: Since I don't own a cell phone, I've never tried charging from an XO. My external USB storage devices are all self-powered; and my other USB devices (adapters, microscopes, keyboards, etc.) are all low-power devices. In about four years of using XO-1.5s, I haven't ever had the XO-1.5 crash when I dynamically plugged any USB device in. I experienced this a couple of years ago in SF when doing my myriad of gadget tests, Hence, the reason I bought my powered USB hub is that I (more than once) plugged in an external USB powered USB mini CD drive and the 1.5 screen went slowly all weird then white. If I remember, I was informed that anything that draws more than 500mA kinda breaks USB rules- and that would include iPhones and iPads. Using a double dongle tries to kluge it on PC's, but this doesn't have any better effect on the 1.5 - something to do with power flowing downhill. I think I was also told that it doesn't happen on the XO 1 because of the presence of some diode or sumpin that keeps the USB device from draining out too fast. Since I now (like Mikus) use powered hubs for anything that needs more than 500mA of power, I have forgotten the exact explanation. I believe it was Richard who explained it to me, and basically told me to cease and desist at the risk of doing damage to the 1.5. Perhaps he can chime in again on this. Cheers, KG mikus __**_ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/**listinfo/develhttp://lists.laptop.org/listinfo/devel ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
RE: Xo1.5 crashes
Hello! We have one XO 1.5 that have that problem.We used it for our Butiá project. When plug an arduino board into the usb, the XO rebootsinstantanly. Now, with our PIC18F.. that it speak directly USB works perfectly! The question: the problem is the usb conversion of the arduino board?Some devices speak serial, no usb direclty.. Regards! Alan Date: Sun, 7 Oct 2012 11:28:52 -0600 Subject: Xo1.5 crashes From: aaronbedf...@gmail.com To: Devel@lists.laptop.org So when i plug one usb device into the xo be it an ipod or a cell phone while running on battery the screen goes white and the laptop reboots. It works fine when plugged in charging though. I just wanted to let you all know what im experiencing. I believe the devices are drawing too much current from the laptop and forcing a reboot. It doesnt matter which usb port i plug it into. Thanks Aaron Bedford IT Admin ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: Xo1.5 crashes
In the case that alan is describing with the XO 1.5 the arduino was connected to the power supply. On Sun, Oct 7, 2012 at 5:58 PM, Alan Jhonn Aguiar Schwyn alan...@hotmail.com wrote: Hello! We have one XO 1.5 that have that problem. We used it for our Butiá project. When plug an arduino board into the usb, the XO reboots instantanly. Now, with our PIC18F.. that it speak directly USB works perfectly! The question: the problem is the usb conversion of the arduino board? Some devices speak serial, no usb direclty.. Regards! Alan Date: Sun, 7 Oct 2012 11:28:52 -0600 Subject: Xo1.5 crashes From: aaronbedf...@gmail.com To: Devel@lists.laptop.org So when i plug one usb device into the xo be it an ipod or a cell phone while running on battery the screen goes white and the laptop reboots. It works fine when plugged in charging though. I just wanted to let you all know what im experiencing. I believe the devices are drawing too much current from the laptop and forcing a reboot. It doesnt matter which usb port i plug it into. Thanks Aaron Bedford IT Admin ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: Xo1.5 crashes
On 10/07/2012 03:22 PM, Andres Aguirre wrote: In the case that alan is describing with the XO 1.5 the arduino was connected to the power supply. See if interposing a __powered__ hub between the XO-1.5 and the arduino will make a difference. WARNING: I have encountered powered USB hubs that have VIOLATED the USB specification - they can emit power on the SMALL socket that normally is used for the USB cable that connects to the computer. It is my understanding that only the LARGE sockets are supposed to be able to supply power to the connected device. [I do not know what kind of USB socket the arduino has.] IIRC, Richard warned about connecting an XO's USB socket to any USB device where that devices's USB socket can emit power (that sets up a condition where a non-XO device can try to send power to the XO -- which is a no_no). mikus ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
