[lug] CUPS printing problem

[Lee Woodworth]

On 06/15/10 01:57, Bruce Long wrote:
> Currently, I am using WiFi to connect to a network printer. I have a little
> gadget that makes a parallel printer into a network printer.
I've used  print servers in the past. The device wishing to print needs to do
the conversion from text/pdf/ps to printer 'language' and send data using a
protocol that supports raw transfer. The two protocols I've seen used by
low-end print servers are lpd and an HP specific protocol related to JetDirect
You will need to make sure your phone's CUPS is configured for raw data
handling when it sends to the network device.

> 
> I do need the system to work with all kinds of printers because I will post
> it to the Maemo community. I have seen people wanting network and bluetooth
> printing, but some folks are on the verge of being able to activate USB Host
> mode. Then I'm sure someone will want USB printing.  I think that once I get
> foomatic and Ghostscript installed it will work. (So far I read the docs on
> those, downloaded the 4 parts of foomatic and built all but the engine. It
> won't build; a problem for another day.)
You should be aware that there are multiple protocols that network printers and
print servers use so you won't be able to provide a single configuration or
a simple set of directions that just works. An added complexity is that some
network printers directly support postscript. For those, the client needs to
send raw postscript (which might have embedded binary data) even when using IPP.
Add in variations in print-server and network printer capabilities plus variations
in ppds for the same printer (eg. printer manufacturer supplied vs foomatic) and
you have lots of cases to deal with.

Some low-end printers (eg. some windows GDI printers) rely on the printing host
to have all of the smarts and to have a low latency bidirectional connection.
Parallel-port print servers generally can't do that so there are printers that
can't be supported that way. The latency from a USB-port print server could
even be too much for some printers.

> 
> Your link to Gutenprint was helpful because I have been looking for the
> driver that I use on my Ubuntu machines. Now I know it is Gutenprint. So far
> I know of four sources of drivers: Those built in to CUPS, Foomatic,
> Ghostscript, and Gutenprint.
The HPLIP project is another source of CUPS drivers for many HP printers. Some
multifunction devices are supported with scanning from a locally
connected printer.

> 
> I'm learning a lot!
Glad to help.