Lego delivers a serial and an USB IR-Tower for communication of a PC with a RCX unit. While the serial tower is plug&play, the USB tower might need some further steps of installation, described in the following HOWTO.
Installation at Linux
First it is necessary that your kernel supports the Lego-USB-Tower. Plug the tower in a free USB socket and watch your /var/log/messages. If your kernel already supports the tower it should display something like:
drivers/usb/misc/legousbtower.c: LEGO USB Tower #0 now attached to major 180 minor 160 drivers/usb/misc/legousbtower.c: LEGO USB Tower firmware version is 1.0 build 134
If it does, go to creating a device-node and test, otherwise you have to rebuild your kernel.
Unplug the tower, switch to your kernel-sources and open the configure-dialog. You'll need root access. On my Gentoo system with kernel-2.6 (and definitely on many other systems) it is:
cd /usr/src/linux make menuconfig
Make sure the following kernel-option is activated:
Device-Drivers --> USB support --> [M] USB Lego Infrared Tower support
It is recommended to compile this as a module, so you are able to load the module only if you want to use the tower and it wouldn't enlarge your kernel. The module will be called legousbtower.
Now recompile your kernel and install the modules:
make && make modules_install
Don't forget to copy your new kernel to your boot directory and reboot the system. After this you may add the new module as root with
modprobe legousbtower
Now plug the tower in a free USB socket. Your /var/log/messages should display something like the messages already mentioned above:
drivers/usb/misc/legousbtower.c: LEGO USB Tower #0 now attached to major 180 minor 160 drivers/usb/misc/legousbtower.c: LEGO USB Tower firmware version is 1.0 build 134
Creating a device-node and test
Make sure a device-node like /dev/usb/legousbtower0 is created. Otherwise, you have to do it yourself! Type as root:
mknod /dev/usb/legousbtower0 c 180 160 chmod 666 /dev/usb/legousbtower0
The chmod-command is required to get access of the tower to a normal user.
You may test the tower with a simple
echo test > /dev/usb/legousbtower0
The green LED on the tower should light for a second.
How to use the tower with brickOS you should visit the brickOS ?-HOWTO.