Support for USB to paralell port converter connected printers?

[carlsa]

I'm trying to connect an old Zebra Z4000 with LPrint but am having problems getting it to work.

The printer is connected with a QinHeng Electronics CH340S (1a86:7584) USB to parallel adapter, this works in CUPS where it is automatically recognized with the URI usb://Zebra%20Technologies/ZTC%20Z4000-300dpi, but it doesn't show up in LPrint if I do lprint devices.

It also doesn't work when I try to add it with lprint add

lprint add -d zebra_test -v usb://Zebra%20Technologies/ZTC%20Z4000-300dpi -m zpl_4inch-203dpi-dt
lprint: Unable to add printer: Unsupported smi55357-device-uri uri value.

I'm runing it on a Rapberry pi (Raspbian) where I build PAPPLE 1.4.6 and LPrint 1.3.1 from sources.

So my question is if this is expected to work and, if not, where I could add it so it is recognized in LPrint?

[michaelrsweet]

There isn't anything special about this, but you generally need to run lprint as root ("sudo lprint devices") for USB access on Linux.

[carlsa]

I solved it, apparently it wasn't being built with support for USB devices, configure --enable-libusb before building helped.

For someone else that is troubleshooting something similar, this is how I found the problem:

• Printers seem to be detected by PAPPL and the USB devices are filtered for printers in libusb_get_device_list.
• I could build PAPPL with configure --enable-debug-printfs and saw that I didn't get the debug messages that libusb_get_device_list would generate and this suggested that it wasn't active.
• configure --help showed a list with options I could enable and --enable-libusb worked

Before doing that, I verified that the USB device didn't use the usblp subsystem with udevadm info --query=all --name=/dev/usb/lp0

I also verified that the conditions that something is detected as a printer from libusb_get_device_list was meet by looking at the USB device information with lsusb -v.