LibNXT for Lego Mindstorms won't compile with scons; usb.h is needed

blesbok · 08-31-2013, 09:33 AM

Hi community, I'm trying to get LibNXT working for Lego Mindstorms.

According to the libnxt-0.3 README

To compile all of this you'll need a copy of libusb 0.1 on your
system, as well as the scons project manager.

- Libusb 0.1: http://libusb.sf.net/
- Scons: http://www.scons.org/

Here's the output of

Code:

apt-file search -x 'libusb\.h$'

apcupsd-doc: /usr/share/doc/apcupsd/examples/libusb.h
libusb-1.0-0-dev: /usr/include/libusb-1.0/libusb.h

So I've installed the libusb that's available and scons. Here's where the problem appears:

run 'scons' in the libnxt directory, and compilation should follow

Attempting that, the following happened:

scons: Reading SConscript files ...
scons: done reading SConscript files.
scons: Building targets ...
gcc -o firmware.o -c -Wall -std=gnu99 -g -ggdb -D_NXT_LITTLE_ENDIAN firmware.c
In file included from firmware.c:31:0:
lowlevel.h:25:17: fatal error: usb.h: No such file or directory
compilation terminated.
scons: *** [firmware.o] Error 1
scons: building terminated because of errors.

In the hope that libusb.h would be a suitable substitute for usb.h, I did this

Code:

$ sudo cp /usr/include/libusb-1.0/libusb.h /usr/include/usb.h

but it gave a screenful of error messages.

This issue (or similar) has been mentioned on
http://code.google.com/p/libnxt/issues/detail?id=6

Which recommends the following:

Quote:

change these two lines in SConstruct:

Code:

Default(BuildEnv.Program('fwflash', 'main_fwflash.c',
                         LIBS=['nxt', 'usb'], LIBPATH='.'))

Default(BuildEnv.Program('fwexec', 'main_fwexec.c',
                         LIBS=['nxt', 'usb'], LIBPATH='.'))

But having done that, the usb.h file is still missing.

Can anyone shed some light?

knudfl · 08-31-2013, 10:37 AM

README : To compile all of this you'll need a copy of libusb 0.1

Quote:

In the hope that libusb.h would be a suitable substitute for usb.h, I did this
$ sudo cp /usr/include/libusb-1.0/libusb.h /usr/include/usb.h

Solution : 1) Delete /usr/include/usb.h
2) Install "libusb 0.1" from source, to --prefix=/usr/
http://packages.ubuntu.com/quantal/libusb-0.1-4 (No -dev package)
Source [libusb_0.1.12.orig.tar.gz] + [libusb_0.1.12-23.debian.tar.gz]
Or use old Debian packages if your OS is 32bits
http://archive.debian.org/debian-arc...n/libu/libusb/
libusb-0.1-4_0.1.5-4_i386.deb + libusb-dev_0.1.5-4_i386.deb

Any questions ? Then please specify your OS :
a) $ uname -m <Enter>
b) $ cat /etc/issue <Enter>

-

John VV · 08-31-2013, 02:40 PM

the LEGO software needs the almost ancient USB1 software
-- yes usb1 in a usb3 world
it dates to 1998 - 2000

so use the LEGACY version and not the current libusb

also from the error

Quote:

lowlevel.h:25:17:

read line 25 of the file in the LibNXT source "lowlevel.h"
it is an "include" statement
it should be this ( a guess so )

Code:

#include  < usb.h >

that means it is looking for the file here "/usr/include/usb.h"
now sometimes some programs look for it in the build folder
if so it will look like this

Code:

#include  "usb.h"

blesbok · 08-31-2013, 02:59 PM

Thank you knudfl for your prompt assistance. That usb.h change was undone when it didn't work.

The OS:
i686; Ubuntu 12.04.2 LTS \n \l; 32-bit

Do I need to first uninstall libusb 1.0 before installing libusb 0.1? If so, how would I go about that? Since it's 32-bit, I'll install the two .deb packages you mention. Is this the right way to install each package?

Quote:

sudo dpkg -i package.deb to --prefix=/usr/

John VV · 08-31-2013, 03:32 PM

both can be installed
but you will likely need to hack the old lego program to look in the right place for the old code .

knudfl · 08-31-2013, 05:48 PM

# 4 .

Sorry, the old packages have conflicts with the installed libusb-0.1-4 (0.1.12-20).
Somehow the new libusb-1.0-0 depends on the already installed libusb-0.1-4,
so libusb-0.1-4 can't be replaced by another package.

On some of the rpm based OS, both libusb versions are available as development packages.
Which means that libNXT can easily be compiled.
And I guess you can use a binary set of "LibNXT" files :
LibNXT provides two executable {fwexec, fwflash} and 'libnxt.a'.
Please try out "libnxt-i386.tar.gz", 19.6 kB :
https://docs.google.com/file/d/0B7S2...it?usp=sharing

"libnxt-i386.tar.gz" is based on https://github.com/rvs/libnxt

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blesbok · 09-01-2013, 09:58 AM

Thanks John and Knud

An rpm-based OS is not an option. Not sure what to do with executables. What's the best way to install these? Would you agree with...?

Quote:

cp fwexec /tmp/fwexec; sudo /tmp/fwexec
cp fwflash /tmp/fwflash; sudo /tmp/fwflash
cp libnxt.a /tmp/fwflash; sudo /tmp/fwflash

Or should I use scons?

Quote:

mkdir /tmp/libnxt
cp fwexec /tmp/libnxt/fwexec
cp fwflash /tmp/libnxt/fwflash
cp libnxt.a /tmp/libnxt/fwflash
cd /tmp/libnxt
sudo scons

knudfl · 09-01-2013, 02:39 PM

# 7.

Quote:

An rpm-based OS is not an option.

No ... but that's what I used to create {fwexec, fwflash, libnxt.a}.

The two executable fwexec, fwflash : Copy those to /usr/local/bin/.
The library libnxt.a : To /usr/local/lib/.

Definitely not to /tmp/ !
** Users should not store files in /tmp. Use /home/** for all build jobs.

And : scons is used only when you compile source code.

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blesbok · 09-01-2013, 03:59 PM

Thanks again, Knud. It's installed but have yet to find a way to make it do anything useful. It looks like nxt-python's the way to go...