gnusb software components
The gnusb has evolved and site is not really up to date. Some information may be inconsistent or missing, please be patient until more documentation becomes available. Binaries in the download are for MacOS X only, at the moment. You'll have to compile them yourself for other platforms, or use older versions (see link below)
In the meantime you can study the source code in the SVN repository which is quite well commented.
An overview of the gnusb software components:
The max external
The gnusb external for Max/MSP and for PureData has 8 outlets for the analog sensor values (PORTA). Output can be 8bit or 10bit, and the inputs can be smoothed with a low-pass filter if necessary.
The two remaining outlets report the state of the digital PORTS if they are configured as an input. Otherwise their output state is simply mirrored on these outlets