[sane-devel] LiDE 90 Half CCD

[Pierre Willenbrock]

Guillaume Gastebois schrieb:
> Hello,
> 
> I see in genesys_gl841.c line 2503 :
> 
> /* gpio part. here: for canon lide 35 */
> 
>     r = sanei_genesys_get_address (reg, 0x6c);
>     if (half_ccd)
> 	r->value &= ~0x80;
>     else
> 	r->value |= 0x80;
> 
> Does it mean that for LiDE 35 GPIO16 is half CCD IO ? Because in LiDE 90, I
> identify GPIO 14 for that.

The GPIO16 is used as half CCD IO. Correct.

> Another thing : In windows snoop, only GPIO 14, 13, 12 and 11 changes state. Is
> it possible that scanner need different gpio state between calibration and
> scanning (and different calibration phases) ? Where to add gpio state change
> code in backend to change gpio between different phases ?

There is no way to know what GPIO 11, 12, 13 do without some experiments 
(or tracing the wires on the pcb, which i advise against).

For example, one GPIO could shut off the LED drivers(thus making black 
level calibration easier), another could be used to save power(as is 
GPIO 9 in Canon LiDE 35).

Currently, i think the only possibly useful GPIOs for calibration and 
scanning are the half ccd and the black led selectors, of which the 
latter is not needed(At least my scanner does not need it, even when 
doing black-level calibration on a white target).

> Thank you.
> 
> Regards
> Guillaume

Regards,
   Pierre