I've got one of these. Among other things it lets me power an external hdd. http://www.cnx-software.com/2013/12/21/x100-raspberry-pi-expansion-board-adds-vga-output-rtc-and-more/
Alternatively make sure when you get a powered hub it does not backfeed in to the pi. You might need to disconnect pin +5V on the usb cable between the pi and the powered usb hub. Guy On Dec 15, 2014 1:37 AM, "E.S. Rosenberg" <esr+linux...@g.jct.ac.il> wrote: > Raspberry Pi uses USB2.0, it can't provide enough current to big > peripheral devices full stop. > It's so bad that plugging in a disk-on-key while it's running can cause a > sufficient voltage drop to reboot the system (after which the d-o-k will > work). > That's why you need to have a powered USB hub, USB3.0 allows more power to > flow through the ports so it will be more efficient with ports (with USB2.0 > external HDDs of the 3,5" variety tend to have a second USB connector to > get extra current). > > HTH, > Eliyahu - אליהו > > 2014-12-14 22:41 GMT+02:00 Amos Shapira <amos.shap...@gmail.com>: >> >> Get a powered USB hub (i.e. a usb hub which also connects to a wall power >> socket). I'm not familiar with RPi USB version but check for USB 3.0 vs. >> 2.0. >> >> On 15 December 2014 at 06:07, Gabor Szabo <ga...@szabgab.com> wrote: >> >>> Hmm, good question. The Raspberry does see the device when it is >>> connected, so is it possible that it needs more >>> power after later on? >>> >>> How can I check? >>> >>> If the problem is lack of current, how can I solve that? Can I put one >>> of these usb hubs that also provide power between the two? >>> >>> Gabor >>> >>> On Sun, Dec 14, 2014 at 8:43 PM, E.S. Rosenberg < >>> esr+linux...@g.jct.ac.il> wrote: >>>> >>>> Are you providing the external HDD with sufficient electricity? The >>>> Raspberry is most likely not capable of providing enough current... >>>> >>>> 2014-12-14 19:30 GMT+02:00 Gabor Szabo <ga...@szabgab.com>: >>>> >>>>> So finally I install the Raspberry Pi I bought a few weeks ago and >>>>> wanted to add an external HDD. >>>>> I plugged in the external hard drive and /var/log/syslog printed the >>>>> following: >>>>> >>>>> >>>>> Dec 14 17:02:55 pi kernel: [ 759.981949] usb 1-1.3: new high-speed >>>>> USB device number 8 using dwc_otg >>>>> >>>>> Dec 14 17:02:55 pi kernel: [ 760.163364] usb 1-1.3: New USB device >>>>> found, idVendor=1058, idProduct=0820 >>>>> >>>>> Dec 14 17:02:55 pi kernel: [ 760.163398] usb 1-1.3: New USB device >>>>> strings: Mfr=1, Product=2, SerialNumber=5 >>>>> >>>>> Dec 14 17:02:55 pi kernel: [ 760.163414] usb 1-1.3: Product: My >>>>> Passport 0820 >>>>> >>>>> Dec 14 17:02:55 pi kernel: [ 760.163429] usb 1-1.3: Manufacturer: >>>>> Western Digital >>>>> >>>>> Dec 14 17:02:55 pi kernel: [ 760.163444] usb 1-1.3: SerialNumber: >>>>> 57583431413432454363833 >>>>> >>>>> Dec 14 17:02:55 pi kernel: [ 760.169522] usb-storage 1-1.3:1.0: USB >>>>> Mass Storage device detected >>>>> >>>>> Dec 14 17:02:55 pi kernel: [ 760.181935] scsi0 : usb-storage 1-1.3:1.0 >>>>> >>>>> Dec 14 17:02:56 pi kernel: [ 761.183065] scsi 0:0:0:0: Direct-Access >>>>> WD My Passport 0820 1012 PQ: 0 ANSI: 6 >>>>> >>>>> Dec 14 17:02:56 pi kernel: [ 761.187365] scsi 0:0:0:1: Enclosure >>>>> WD SES Device 1012 PQ: 0 ANSI: 6 >>>>> >>>>> Dec 14 17:02:56 pi kernel: [ 761.189473] sd 0:0:0:0: [sda] Spinning >>>>> up disk... >>>>> >>>>> Dec 14 17:02:56 pi kernel: [ 761.277106] sd 0:0:0:0: Attached scsi >>>>> generic sg0 type 0 >>>>> >>>>> Dec 14 17:02:56 pi kernel: [ 761.278094] scsi 0:0:0:1: Attached scsi >>>>> generic sg1 type 13 >>>>> >>>>> >>>>> But then when I try to run >>>>> >>>>> >>>>> $ sudo fdisk /dev/sda >>>>> >>>>> I get >>>>> >>>>> fdisk: unable to open /dev/sda: No such device or address >>>>> >>>>> $ ls -l /dev/sda >>>>> >>>>> brw-rw---T 1 root floppy 8, 0 Dec 14 17:21 /dev/sda >>>>> >>>>> $ sudo fdisk -l >>>>> >>>>> only lists the sdcard >>>>> >>>>> >>>>> The external disk is brand new and it has NTFS on it. I have not >>>>> handled disk in linux for a long time, but a I recall I am supposed to use >>>>> fdisk to partition it and then use mkfs.ext4 to format. >>>>> >>>>> >>>>> So what am I missing here? >>>>> >>>>> >>>>> Gabor >>>>> >>>>> >>>>> >>> >>> _______________________________________________ >>> Linux-il mailing list >>> Linux-il@cs.huji.ac.il >>> http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il >>> >>> >> >> -- >> <http://au.linkedin.com/in/gliderflyer> >> > > _______________________________________________ > Linux-il mailing list > Linux-il@cs.huji.ac.il > http://mailman.cs.huji.ac.il/mailman/listinfo/linux-il > >
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