[sane-devel] rts8891: Umax Astra 4450 does not work

[Ondrej Zary]

On Friday 08 May 2015 21:46:36 Ondrej Zary wrote:
> On Friday 08 May 2015 16:17:53 Ondrej Zary wrote:
> > On Thursday 07 May 2015 23:32:28 Ondrej Zary wrote:
> > > Hello,
> > > I just got Umax Astra 4450 (same as 4400 except with UTA?) for a while
> > > and tested it with SANE. Unfortunately, it does not work. The lamp
> > > turns on and the head moves a bit, then goes back (two times) and the
> > > scan ends with these errors:
> > >
> > > [rts8891] simple_scan: failed to wait for data
> > > [rts8891] gain_calibration: failed scan data
> > > [rts8891] sane_start: failed to do gain calibration!
> > > scanimage: sane_start: Error during device I/O
> >
> > I've modified sane_start() in rts8891.c to not fail if gain_calibration()
> > returns error. It now scans the complete area and the output resembles
> > what's in the scanner (black template for UTA use with green text) but
> > it's blurry, shifted horizontally (and the gain is wrong, of course):
> > http://www.rainbow-software.org/linux_files/umax_astra_4450/no_gain_calib
> >ra tion.ppm.gz
> > http://www.rainbow-software.org/linux_files/umax_astra_4450/no_gain_calib
> >ra tion.log
> >
> > Looks like there's a problem with the sensor type?

Gain calibration fails because dev->left_offset (and thus xstart) is negative. 
If I set xstart to 4, gain calibration passes (although it's wrong: ends 
after first pass with 0x1f,0x1f,0x1f).

So find_margin() does not work...

-- 
Ondrej Zary