Beaglebone Angstrom: Info on Python libraries

GoogleGroups
1

Hi all,

I've recently bought the Tinkerforge modules and want to link them up
to Beaglebone over usb and write code in Python to build a maze
solving micro mouse. I'm just learning Python (which is relatively
easy it seems) and have no experience in Linux either so really over-
stretching myself. The last code I wrote was Cobol about 25 years
ago. I don't plan on using Linux much, just enough so that I can
write the Python code in an IDE and copy it onto the SD Card and run
it.

Apparently for this to work I need to have Python-Twisted, Python-
Gudev and libusb-1.0-0.

I've searched like crazy on this and the best I can seem to figure out
is that Angstrom probably has Python-Twisted, Libgudev and
libusb-1.0-0. So I wanted to see whether anyone of you could confirm
this? I can't see any reference to Python-Gudev and not sure whether
it's different to libgudev or whether it is in fact part of the
default build of Angstrom on Beaglebone.

If not then could someone give me a clue how I'd get the missing parts
onto the system. In terms you'd use to someone who's never seen Linux
before please?

Many thanks

2

Hi

This might be of help:

Part of Angstrom is a 'package manager'. That in effect makes it easy
to install packages that you might need. Whilst I don't know what
these python modules 'gudev', 'twisted', 'usb' and so on are, if they
exist for angstrom but have not been shipped, you can most likely
install these using the command 'opkg install ...'.

I did this for example with the python setuptools which are not
shipped on the beaglebone, but I could install them by using the above
command.

Martin

3

Hi,

The short answer is that python-twisted might be a problem.

The long answer is...

Angstrom does have packages for all 3, according to Feed Browser at
http://www.angstrom-distribution.org/repo/

On the Angstrom demo image that I'm using on the Beaglebone (the most
recent one), libusb-1.0.0 is installed, but the others aren't.
One way to check what is installed on your Beaglebone is to "grep" the
packagename, as in the following example:

beaglebone:~# opkg list-installed | grep "libusb"
libusb-0.1-4 - 1:0.1.3-r2
libusb-1.0-0 - 1.0.8-r2

To see what packages are available in the Beaglebone Anstrom
repository, use the "opkg list" comamnd. (You should always run opkg
update first, to make sure you have the latest info about the
repository)

beaglebone:~# opkg update
beaglebone:~# opkg list | grep "libgu"
libgudev-1.0-0 - 175-r0 - udev version 175-r0

To install this package:

beaglebone:~# opkg install libgudev-1.0-0

However, according to "opkg list" python-twisted isn't available in
the beaglebone's repository. The versions listed at
http://www.angstrom-distribution.org/repo/ don't include one for
Python 2.7, which is the Python included on the beaglebone Demo image
-- perhaps that's why.

In general, I've found that the best way to get the latest and
greatest Python packages is to use the easy_install command, which is
part of the Python setuptools package that Martin mentioned:

beaglebone:~# opkg install python-setuptools
beaglebone:~# easy_install twisted

However, I just tried it, and the installed for Python twisted tried
to compile some C code, and couldn't find the necessary headers.
Building C programs natively on the Beaglebone is a whole different
ballgame, and I can't give you much help there. Maybe someone else
can?

Dan.