No USB scanners are supported and there are no plans to support them in the future. Other projects are working on support for USB scanners. See the PROJECTS file for more detail. We cannot add support for the FB310P or FB320P at the moment, but contact us if you have one of these scanners and would really like to help.
IMPORTANT: this is alpha code. While we have made every effort to make it as reliable as possible, it will not always work as expected. Feedback is still appreciated. Please send any bug reports to the maintainers as listed on the web page (listed in SEE ALSO below).
On Linux 2.4 kernels this will be of the form parport0 or older (2.2) kernels may produce names like 0x378 or simply 0 depending on your module configuration. Check the contents of /proc/parport if it exists. If you don't want to specify a default port (or don't know its name), the backend should be able to detect which port your scanner is on.
The supported options are currently ieee1284, calibrate, and force_nibble
Option ieee1284 portname defines which port to use. The format of portname is OS dependant, based on the names presented by libieee1284. Please only have one of these lines, or all but one will be ignored.
Option calibrate cal-file [portname] defines which calibration file to use on a per-port basis. If you only have one scanner, the portname argument may be omitted - but be careful as this will cause problems on multi-scanner systems. You may have as many of these lines as you like, as long as each has a unique port name. The tilde (`~') character is acceptable and will be expaned to the value of the HOME environment.
Option force_nibble forces the driver to use nibble mode even if ECP mode is reported to work by libieee1284. This works-around the rare issue of ECP mode being reported to work by the library, then not working.
Hit the "Calibrate" button before scanning. It vastly improves the quality of scans.
To enable automatic detection of your scanner, uncomment the "canon_pp" line from /etc/sane.d/dll.conf
Example: export SANE_DEBUG_CANON_PP=4
Other Notes
ECP mode in libieee1284 doesn't always work properly, even with new hardware. We beleive that this is a ppdev problem. If you change the configuration file to include force_nibble , the problem will go away, but you will only be able to scan in nibble mode.
Sometimes the scanner can be left in a state where our code cannot revive it. If the backend reports no scanner present, try unplugging the power and plugging it back in. Also try unplugging printers from the passthrough port.
The scanner will not respond correctly to our commands when you first plug in the power. You may find if you try a scan very soon after plugging in the power that the backend will incorrectly report that you have no scanner present. To avoid this, give it about 10 seconds to reset itself before attempting any scans.
Many thanks to Kevin Easton for his comments and help, and Kent A. Signorini for his help with the N340P.