On 15-09-12 08:11 AM, Ed Kapitein wrote: > Hi, > i want to use a raspberry pi to charge the BQ 4.5, without a (powered) hub. > The BQ is not charging when i plug it into the pi, and the pi never > enumerates the BQ on its usb bus.
Sounds like they're both OTG connections, each waiting for the other to assert host mode. It's possible neither device has a kernel that supports host mode on the OTG port: you can check on the devices using the command line 'grep CONFIG_USB_OTG /boot/config-$(uname -r)'. In particular, this is required on the Pi, which has a USB Standard-A connector so needs to play the host. It's also very possible you're using a regular USB cable and not an OTG cable, so host-slave nego never happens and they're both waiting in slave mode for the other device to assert dominance through hardware signalling. See the Wikipedia entry https://en.wikipedia.org/wiki/USB_On-The-Go for a detailed description. -- Stephen M. Webb <stephen.w...@canonical.com> -- Mailing list: https://launchpad.net/~ubuntu-phone Post to : ubuntu-phone@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-phone More help : https://help.launchpad.net/ListHelp
