[sane-devel] stepping motor control canon lide 25

[Dr.-Ing. Ingo D. Rullhusen]

Hello,

i've made the following changes:

nn at hf27:~/tmp/mein_Canon_LiDE_25$ diff -ac plustek-usbdevs.c 
../sane-backends-1.0.18/backend/
*** plustek-usbdevs.c   2007-02-17 19:25:28.000000000 +0100
--- ../sane-backends-1.0.18/backend/plustek-usbdevs.c   2006-05-31 
18:31:47.000000000 +0200
***************
*** 718,724 ****
   */
  static DCapsDef Cap0x04A9_0x2220 =
  {
!       {{ 0, 100}, 50, 10, {2580, 3550}, {75, 75}},
        {{ 0,   0},  0,  0, {0, 0}, { 0, 0 }},
        {{ 0,   0},  0,  0, {0, 0}, { 0, 0 }},
        {{ 0,   0},  0,  0, {0, 0}, { 0, 0 }},
--- 718,724 ----
   */
  static DCapsDef Cap0x04A9_0x2220 =
  {
!       {{ 0, 100}, 50, 10, {2550, 3508}, {75, 75}},
        {{ 0,   0},  0,  0, {0, 0}, { 0, 0 }},
        {{ 0,   0},  0,  0, {0, 0}, { 0, 0 }},
        {{ 0,   0},  0,  0, {0, 0}, { 0, 0 }},
***************
*** 2338,2344 ****
        0.0,    /* dHighSpeed                                     */
        100,    /* wIntegrationTimeLowLamp                        */
        100,    /* wIntegrationTimeHighLamp                       */
!       1211,   /* wMotorDpi (Full step DPI)                      */
        512,    /* wRAMSize (KB)                                  */
        3.75,   /* dMinIntegrationTimeLowres (ms)                 */
        5.75,   /* dMinIntegrationTimeHighres (ms)                */
--- 2338,2344 ----
        0.0,    /* dHighSpeed                                     */
        100,    /* wIntegrationTimeLowLamp                        */
        100,    /* wIntegrationTimeHighLamp                       */
!       1200,   /* wMotorDpi (Full step DPI)                      */
        512,    /* wRAMSize (KB)                                  */
        3.75,   /* dMinIntegrationTimeLowres (ms)                 */
        5.75,   /* dMinIntegrationTimeHighres (ms)                */
nn at hf27:~/tmp/mein_Canon_LiDE_25$


and additionally


rull at hf27:~/tmp/mein_Canon_LiDE_25$ diff plustek-usbdevs.c /etc/sa     
samba/  sane.d/
rull at hf27:~/tmp/mein_Canon_LiDE_25$ diff -ac  plustek.conf /etc/sane.d/
*** plustek.conf        2007-02-17 18:44:44.000000000 +0100
--- /etc/sane.d/plustek.conf    2006-05-02 11:27:51.000000000 +0200
***************
*** 57,73 ****
  # (WARNING: there's no internal range check!!!)
  #
  # for the normal scan area
! # 1.5mm x 3.0mm
! option posOffX 12
! option posOffY 23
 
  # for transparencies
! option tpaOffX 12
! option tpaOffY 23
 
  # for negatives
! option negOffX 12
! option negOffY 23
 
  #
  # for setting the calibration strip position
--- 57,73 ----
  # (WARNING: there's no internal range check!!!)
  #
  # for the normal scan area
! #
! option posOffX 0
! option posOffY 0
 
  # for transparencies
! option tpaOffX 0
! option tpaOffY 0
 
  # for negatives
! option negOffX 0
! option negOffY 0
 
  #
  # for setting the calibration strip position
***************
*** 97,104 ****
  #
  # use alternate calibration routines
  #
! #####
! option altCalibration 1
 
  #
  # for skipping whole calibration step
--- 97,103 ----
  #
  # use alternate calibration routines
  #
! option altCalibration 0
 
  #
  # for skipping whole calibration step
rull at hf27:~/tmp/mein_Canon_LiDE_25$


The altCalibration option seems to have no significant effect. (colors 
little bit better?) Any changes in the variables dMaxMotorSpeed and 
dMaxMoveSpeed cannot improve the y resolution error, only more noise(!!) 
or more error.

This selected settings avoid to touch the limit and use a maximum amount 
of the glass plate. The y resolution is fitted effectively to the x 
resolution (=exact value).

BTW, the default values are already save and good, but it would be nice 
to fit the personal needs, if options like

MotorDpiAdjust=+11
XSizeAdjust=+30
YSizeAdjust=+42

could be simply added to the conf file, instead of playing around in the 
source file.

Thanks,
   Ingo