A1400 porting thread

Crispy

41

Re: A1400 porting thread

« Reply #100 on: 09 / June / 2015, 15:22:23 »

Advertisements

I'll try that; I think you might be right; when I tried keeping the slow zoom pressed continually, so that it moved constantly in slow increments, it didn't crash. However, when I stopped shooting, the camera turned itself off, and had to be restarted. I've checked in the settings and the >Auto Power Down setting is turned off, so I don't know what else it could be...I'll try it with fresh batteries and see what happens.

Logged

Crispy

41

Re: A1400 porting thread

« Reply #101 on: 10 / June / 2015, 05:55:52 »

OK, I think I've solved this issue: I tried fresh batteries and the same problem occurred when I moved the zoom lever sporadically, rather than holding it down continually to advance it in small increments.

Logged

waterwingz

12140

Re: A1400 porting thread

« Reply #102 on: 10 / June / 2015, 09:36:05 »

Quote from: Crispy on 10 / June / 2015, 05:55:52

OK, I think I've solved this issue: I tried fresh batteries and the same problem occurred when I moved the zoom lever sporadically, rather than holding it down continually to advance it in small increments.

So it's a hardware issue with that camera. Fortunately you will not be changing zoom position in a book scanner application after you determine the initial settings. (One more reason to use a startup CHDK script - setting the zoom to a desired position each time the camera starts).

Logged

Ported : A1200 SD940 G10 Powershot N G16

Crispy

41

Re: A1400 porting thread

« Reply #103 on: 10 / June / 2015, 09:45:24 »

I'll have a go at writing a script to preload my zoom value. Actually, that could be part of my master plan of creating a 'do everything' script that would automatically set zoom, iso, av, tv nd filter and so on. I need to get to grips with writing a script...

Logged

waterwingz

12140

Re: A1400 porting thread

« Reply #104 on: 10 / June / 2015, 09:49:54 »

Quote from: Crispy on 10 / June / 2015, 09:45:24

I'll have a go at writing a script to preload my zoom value. Actually, that could be part of my master plan of creating a 'do everything' script that would automatically set zoom, iso, av, tv nd filter and so on. I need to get to grips with writing a script...

That's a common approach for book scanner applications using CHDK. You can even set the script to run automatically when the camera starts so that all you then need to do is position the pages and press the remote button. I can whip a quick sample script up for you if you'd like?

When you get really into this, you will probably want to start using chdkptp to automatically download and arrange the images on your PC for you as you work. But that's a subject for another day.

Logged

Ported : A1200 SD940 G10 Powershot N G16

Crispy

41

Re: A1400 porting thread

« Reply #105 on: 10 / June / 2015, 09:51:43 »

Hey, if you could create a sample script that I could take apart and tinker with that would be tremendously helpful. I usually do better at coding when I get to reverse engineer something!

Logged

waterwingz

12140

Re: A1400 porting thread

« Reply #106 on: 10 / June / 2015, 13:38:42 »

Quote from: Crispy on 10 / June / 2015, 09:51:43

Hey, if you could create a sample script that I could take apart and tinker with that would be tremendously helpful. I usually do better at coding when I get to reverse engineer something!

There are two approaches that can be used here.

The first is a startup script that atttempts to autoconfigure CHDK (by overriding the CHDK menu settings) and then exiting.

The second is a script that runs at startup that actually performs the book scanner functionality directly.

The second option is easier to write, somewhat more flexible, and ulitmately what you want when you go into production. Set it as the startup script and when you power your scanner, the cameras will be ready to go.

I've attached a sample Lua script you can use for the second mode. It should give you a good start on something to fiddle with.

scanner.lua (2.35 kB - downloaded 17 times.)

Logged

Ported : A1200 SD940 G10 Powershot N G16

Crispy

41

Re: A1400 porting thread

« Reply #107 on: 10 / June / 2015, 15:29:52 »

Hi!

Many many thanks for this! I've looked at the script in notepad and tried modifying some of its functions; it looks fairly straightforward.

The only thing I am having trouble with is determining my zoom values from the information displayed on the screen; I can't see any readout which indicates what % zoom I'm at?

Ideally, I'd zoom to the resolution I'd like, note the correct % and then input that into the script?

Logged

waterwingz

12140

Re: A1400 porting thread

« Reply #108 on: 10 / June / 2015, 15:39:13 »

Quote from: Crispy on 10 / June / 2015, 15:29:52

The only thing I am having trouble with is determining my zoom values from the information displayed on the screen; I can't see any readout which indicates what % zoom I'm at? Ideally, I'd zoom to the resolution I'd like, note the correct % and then input that into the script?

Canon zoom settings are actually made in terms of discrete "steps". Canon P&S cameras do not have continuous zoom - they have a discrete number of steps. And the number of steps varies from camera to camera - typically from a low of 7 or 8 steps on a low end camera out to just over a hundred steps on the megazooms.

To generalize things in my script, I let you pick a % of full scale and then calculate the zoom step closest to that percentage.

You can display the zoom step using one of the CHDK Misc Value type OSD functions. If you want to "dumb down" the script, just work in zoom steps and get rid of my percentage to steps calculation near the start.

Logged

Ported : A1200 SD940 G10 Powershot N G16

Crispy

41

Re: A1400 porting thread

« Reply #109 on: 10 / June / 2015, 15:55:55 »

Ah thanks that's really useful. It's strange though; I've edited the zoom visibility in OSD Settings and it's activated, but still nothing changes on the OSD when I zoom in or out. Is this to be expected?

Logged