SX20 get_usb_power issue

gwenger

2

« on: 15 / January / 2011, 16:29:29 »

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Hey everyone I'm very new to this so I might just be doing something stupid, but I figured I'd ask around.
I'm trying to run a script on my SX20 IS that will zoom in, zoom out, and take pictures based on power supplied via usb. This should be very simple script, but whenever I apply power to the usb port, my camera goes into playback mode until I stop supplying power. I've tried this using 3 volts, 4.3 volts, and 5 volts from two AA batteries, three AA batteries, and my computer's usb port respectively.
Has anyone encountered an issue like this before? Any help would be much appreciated.

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reyalp

14110

Re: SX20 get_usb_power issue

« Reply #1 on: 15 / January / 2011, 16:54:53 »

Quote from: gwenger on 15 / January / 2011, 16:29:29

Hey everyone I'm very new to this so I might just be doing something stupid, but I figured I'd ask around.
I'm trying to run a script on my SX20 IS that will zoom in, zoom out, and take pictures based on power supplied via usb. This should be very simple script, but whenever I apply power to the usb port, my camera goes into playback mode until I stop supplying power. I've tried this using 3 volts, 4.3 volts, and 5 volts from two AA batteries, three AA batteries, and my computer's usb port respectively.
Has anyone encountered an issue like this before? Any help would be much appreciated.

You need to enable USB remote, otherwise the canon firmware sees USB power and assumes it has been connected to a PC.

See http://chdk.wikia.com/wiki/CHDK_User_Manual#Remote_Parameters

If you have USB remote enabled, then this build is not properly masking USB power.

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Don't forget what the H stands for.

SkyWalker9

301
SX20 IS (fw 1.02b)

Re: SX20 get_usb_power issue

« Reply #2 on: 15 / January / 2011, 23:13:40 »

Quote from: gwenger on 15 / January / 2011, 16:29:29

...whenever I apply power to the usb port, my camera goes into playback mode until I stop supplying power. I've tried this using 3 volts, 4.3 volts, and 5 volts from two AA batteries, three AA batteries, and my computer's usb port respectively. Has anyone encountered an issue like this before? Any help would be much appreciated.

@gwenger

I've been using a Ricoh CA-1 cable switch with the SX20 CHDK for a few weeks now (http://chdk.setepontos.com/index.php?topic=4348.msg59492#msg59492 ) and the only thing required was what @reyalp mentioned. I haven't tried scripting anything for the switch yet. So far it has worked great, especially when it would have been very difficult to capture shots using the count down timer.

Just enable to start using: Miscellaneous Stuff>Remote Parameters>Enable Remote

« Last Edit: 16 / January / 2011, 11:06:18 by SkyWalker9 »

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gwenger

2

Re: SX20 get_usb_power issue

« Reply #3 on: 18 / January / 2011, 12:18:00 »

Thanks a lot, that worked. For some reason I had actually disabled USB remote just before testing my script, but now everything is working properly.

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