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Shooting while transferring over USB

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Re: Shooting while transferring over USB
« Reply #20 on: 20 / December / 2013, 23:56:56 »
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Hmmm, although I will test my idea the multithread/multiinstance solution is very promising too. I wasn't aware of that. I suppose it would be worth to have 2 or even 4 downloaders running at the same time. Thats probably the better way to go. Thanks a lot.

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Online reyalp

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Re: Shooting while transferring over USB
« Reply #21 on: 20 / December / 2013, 23:58:29 »
Any chance of a C&P error during the early part of that port so that the mmio values were not correct?
For ports in general? I would say very high.

On D10, I verified that the MMIO is the one modified by SetSDPwrPort, so it's at least related to the SD card somehow.
Don't forget what the H stands for.

Re: Shooting while transferring over USB
« Reply #22 on: 21 / December / 2013, 03:34:32 »
What does that mean? What is a C&P error? You got the wrong adresses for the cards? They depend on size too?

Re: Shooting while transferring over USB
« Reply #23 on: 21 / December / 2013, 09:24:21 »
What does that mean? What is a C&P error? You got the wrong adresses for the cards? They depend on size too?
C&P means cut & paste.  Many CHDK ports (most?) start by copying (C&P) the port from another camera. If the port is done carefully,  every file and every address reference is then carefully changed to match the configuration of the new camera.  But sometimes, if things get missed, the port appears to work anyway.  Often it works because the feature supported by the incorrectly copied code does not get tested by the person doing the port.

In this case, the code is question is in the boot loader.  It's the first code executed when CHDK loads so if a new CHDK porter gets this to work, its unlikely they ever go back to check it.   It's interesting that some cameras have the code for SD card power off and others do not.   I suppose as an experiment I could remove it from the code for my various cameras and see what happens.   

Won't get to that for a couple of days though.


Ported :   A1200    SD940   G10    Powershot N    G16


Re: Shooting while transferring over USB
« Reply #24 on: 21 / December / 2013, 09:28:54 »
Hmmm, although I will test my idea the multithread/multiinstance solution is very promising too. I wasn't aware of that. I suppose it would be worth to have 2 or even 4 downloaders running at the same time. Thats probably the better way to go. Thanks a lot.
That's what I was trying to tell you when I said this :
IIRC, the PTP limitation you mention is more a limitation of the current implementation of the PC side of the ptp code.   Communicating with multiple USB connected devices is technically possible,  its just not something that has been done for CHDK enabled cameras yet.
It's more a question of somebody with the time & experience & need writing the code rather than a technical limitation.
Ported :   A1200    SD940   G10    Powershot N    G16

Re: Shooting while transferring over USB
« Reply #25 on: 21 / December / 2013, 11:01:25 »
Yes, what I did not realize is the fact that simply starting some instances of CHDK already provide multithreading.

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Re: Shooting while transferring over USB
« Reply #26 on: 21 / December / 2013, 16:35:57 »
In this case, the code is question is in the boot loader.  It's the first code executed when CHDK loads so if a new CHDK porter gets this to work, its unlikely they ever go back to check it.   It's interesting that some cameras have the code for SD card power off and others do not.   I suppose as an experiment I could remove it from the code for my various cameras and see what happens.   
Indeed, it does not appear to be needed on D10 or elph130. I suspect it isn't needed on many ports that have it.

When removing it, be sure to check booth boot methods.
Don't forget what the H stands for.

Re: Shooting while transferring over USB
« Reply #27 on: 21 / December / 2013, 18:42:42 »
Sorry, I can't follow the discussion here. Why has there been code to switch.off card power while booting? And why should this be disabled when booting? Aren't we looking for a function to be called when needed?

It would be nice to find out if the idea would do it. All in all it could be a neat thing to make the camera cards available as real drives on a PC.


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Re: Shooting while transferring over USB
« Reply #28 on: 21 / December / 2013, 19:07:32 »
Sorry, I can't follow the discussion here. Why has there been code to switch.off card power while booting?
Presumably, because the canon firmware (on some camera, details lost in antiquity...) expects things to be in a particular state.
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And why should this be disabled when booting?
I'm not sure what you are asking here. The discussion with waterwingz was about the fact that the call to turn off the SD card may not actually be needed on many cameras.

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Aren't we looking for a function to be called when needed?
As it turns out, there is an event proc which appears to do the same thing on at least some cameras. See the last post in this thread: http://chdk.setepontos.com/index.php?topic=5563.msg102981#msg102981
Don't forget what the H stands for.

Re: Shooting while transferring over USB
« Reply #29 on: 29 / December / 2013, 12:08:08 »
Yes, what I did not realize is the fact that simply starting some instances of CHDK already provide multithreading.

In case this might be useful for you - the possible benefit had not registered when I first read it. If you use VBA it looks like a pretty straightforward way to get console output - it seems there are some remaining bugs though:

http://chdk.setepontos.com/index.php?topic=10060.msg103939#msg103939     

For my related memory only:
(i) running other executables from chdkptp this has information on using lua 'os.execute':

http://chdk.setepontos.com/index.php?topic=8801.msg104000#msg104000]
 
(ii) running VBA from AutoIT:
http://www.autoitscript.com/autoit3/docs/libfunctions/_ExcelReadSheetToArray.htm
« Last Edit: 29 / December / 2013, 15:05:41 by andrew.stephens.754365 »

 

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