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I have a problem where I need to read a usb-stick or a usb keyboard: When I plug in the USB stick or keyboard I can't get power to the device. dmesg says nothing

I tried:

for device in $(ls /sys/bus/usb/devices/*/product); 
  do echo $device
  cat $device;
done

for getting information in console and I get this output:

/sys/bus/usb/devices/usb1/product
Freescale On-Chip EHCI Host Controller 

I can't see any kingston usb stick or keyboard.

Quesitons:

  1. How can I power my usb device mdev or /sys/bus/usb/devices/*/power
  2. How to read data from keyboard or usb stick.
  • which embeded and which unix distribution do you use? – rubo77 Oct 21 '13 at 12:02
  • Linux version 2.6.35.3 (panu@ubuntu) (gcc version 4.4.1 (Sourcery G++ Lite 2010q1-202) ) #1 PREEMPT Linux 2.6.35.3 armv5tejl Built with buildroot – user257980 Oct 21 '13 at 14:09
  • Some very small (thin) USB sticks can be inserted upside down; try turning the usb stick over... – ChuckCottrill Oct 21 '13 at 19:52
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observe the output in syslog with:

tail -f /var/log/syslog

while plugging in and out the USB-device.

If you have no syslog, install some Logging framework for embedded linux

  • there is no syslog in this embbedded linux – user257980 Oct 21 '13 at 11:15
  • maybe you find a simple logging framework in my edit – rubo77 Oct 21 '13 at 12:04
  • Theres no logs for usb when connecting usb stick. – user257980 Oct 21 '13 at 14:07
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Solution wasn't simple.

I need to configurate /sys/class/gpio/ for enabling internal 5V step-up regulator.

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