Noob - USB Peripherals not showing up in /dev - xm/Angstrom


Sorry about that: that article on my blog is out-of-date. Thanks for the reminder to clean it up. :slight_smile:

You should find that depmod and modprobe are in the path, so those commands can be run without the “/opt/bin/” part (as root)


depmod -a
modprobe ftdi-sio

I think the modutils approach to loading kernel modules is also out-of-date – I haven’t run Angstrom on my XM for awhile, but I don’t think /etc/modutils exists. If it doesn’t, try using /etc/modules instead:

root@beaglebone:~# echo ftdi_sio >> /etc/modules
root@beaglebone:~# echo usbserial >> /etc/modules
root@beaglebone:~# update-modules

Before doing all that, you need to install the packages for these kernel modules, if you haven’t already.

opkg install kernel-module-usbserial kernel-module-ftdi-sio

And if you haven’t already updated your packages (sorry, I seem to be listing the steps backwards), you’ll need to do that as well:

opkg update
opkg upgrade

So, after installing the kernel modules, if you enter the following:

depmod -a
modprobe ftdi-sio

… then plug in your USB cable, you should see something like the following at the end of the dmesg output:

[12825.128906] ftdi_sio 2-2.2:1.0: FTDI USB Serial Device converter detected

[12825.129028] usb 2-2.2: Detected FT232RL

[12825.129058] usb 2-2.2: Number of endpoints 2

[12825.129058] usb 2-2.2: Endpoint 1 MaxPacketSize 64

[12825.129058] usb 2-2.2: Endpoint 2 MaxPacketSize 64

[12825.129089] usb 2-2.2: Setting MaxPacketSize 64

[12825.130035] usb 2-2.2: FTDI USB Serial Device converter now attached to ttyUSB0


if ftdi driver is installed and in demod then it should load
automatically when you plug in a device. I did not install modules by
the opkg command but compiled kernel with ftdi included as a module.
It starts automatically as written above

Dan - Thanks for the update…

I tried all of that this morning and still I get nothing. I’m seeing both (I have two USB-Serials) in the dmesg but never is it attaching to a tty location.

Both USB-Serial adapters appear to be the prolific chipset, which may be my problem. I went ahead and ordered to FTDI chipset ones today and they will be here tomorrow.

Any thoughts if it is the chipset that is causing the problem and if so is there a way to rectify it?

Here is the associated output from dmesg after doing everything provided above and plugging both usb-serial adapters into the powered hub:

[ 2548.048828] usb 2-2.5.6: new full speed USB device using ehci-omap and address 11
[ 2548.174835] usb 2-2.5.6: New USB device found, idVendor=067b, idProduct=2303
[ 2548.182312] usb 2-2.5.6: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 2548.190124] usb 2-2.5.6: Product: USB-Serial Controller D
[ 2548.195556] usb 2-2.5.6: Manufacturer: Prolific Technology Inc.
[ 2550.095703] usb 2- new full speed USB device using ehci-omap and address 12
[ 2550.239715] usb 2- New USB device found, idVendor=06cd, idProduct=0121
[ 2550.247283] usb 2- New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 2550.255310] usb 2- Product: Keyspan USA-19H
[ 2550.260467] usb 2- Manufacturer: Keyspan, a division of InnoSys Inc.

Just figured it out…

If you are running USB- Serial adapters with Prolific chipset (PL2303) and Beagleboard -xm Angstrom…

Here is what you need to do to get it to work

opkg update
opkg upgrade

opkg install kernel-module usbserial
opkg install kernel-module-pl2303

echo pl2303 >> /etc/modules
echo usbserial >> /etc/modules

depmod -a

modprobe pl2303

That should do it! Thanks for help everyone…got me pointed in the right direction!

So it found them.. But do you really have the modules installed?

find /lib/modules/`uname -r`/ | grep pl2303


So it found them… But do you really have the modules installed?

Yep…it showed up