[sane-devel] HP SCANJET 4500c trouble

[Ilia Sotnikov]

On Wed, Jan 6, 2010 at 7:12 AM,  <gcasados at solar.cinvestav.mx> wrote:
...
> [sanei_debug] Setting debug level of hp5590 to 50.
> [hp5590] SANE backed for HP ScanJet 4500C/4570C/5500C/5550C/5590/7650 1.0.5
> [hp5590] (c) Ilia Sotnikov <hostcc at gmail.com>
> [hp5590] attach_usb_device: Opening USB device
> [hp5590] attach_usb_device: USB device opened
> [hp5590] hp5590_init_scanner
> [hp5590] hp5590_cmd: USB-in-USB: command : 0012
> [hp5590] hp5590_control_msg: USB-in-USB: core data: no
> [hp5590] hp5590_control_msg: USB-in-USB: sending control msg
> [hp5590] hp5590_control_msg: USB-in-USB: checking acknowledge for control
> message
> [hp5590] hp5590_get_ack
> [hp5590] hp5590_get_ack: USB-in-USB: accepted
> [hp5590] hp5590_get_ack: USB-in-USB: not accepted (status 0)

Hello, Gaspar!

The acknowledgement after sending a command to scanner was returned as
0 instead of 1. The code checks for that and reports the error. Your
device looks similar to HP 5550C (at least, has the same USB Vendor
ID/Product ID), and HP5550 works rather well.

> The scanner hangs after scanimage exits.

That's often indicates that scanner got a sequence of commands it didn't expect.

> Does anybody know something about this chip?
> I hope this numbers could be useful.

I wasn't able to find any techical information several years ago, so I
decided to implement the backend based only on USB data observations.

There are two ways to resolve the issue - a) take a USB sniff from
Windows machine, or b) consider acknowledgement status 0 valid as well
as 1. I would go a) as b) is 'quick hack' anyway.

Do you have any Windows machine for experiments? Then you could use
SniffUsb from http://www.pcausa.com/Utilities/UsbSnoop/ and capture
the USB data from eg. 100 DPI BW scan (to reduce the log size), then
send me the log file for analyzing.

Best regards,
-- 
 Ilia Sotnikov