Triggering 4 cameras from computer

jfonfria

7

« on: 08 / July / 2012, 18:45:46 »

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Hello to everyone,

My name is Juan José, and I'm a mechanical engineering. I'm developing an economic system for industrial photogrammetry, and I think CHDK could be very helpfull to me. I have bought 4 SX130 cameras (they have very good resolution: industrial cameras have prizes from 1000-1500 euros, and only the camera withouth the objectives...).

In this moment I would like to trigger the four cameras from the computer, and I don't know how to do this (I think it is possible, because for example a similar action is developing in CHDK page for only one, and it could be similar). I would be very gratefull if you could tell to me similar references or information. I want to do this:

1) Connect the camera by mini-USB - A-USB to the computer.
2) Fight the cameras when I say this (but say it from the computer)

And anything more: is it possible to take a pohoto and also that the computer would be used as a power supply to the camera. If it could not be possible I have found power-suppliers for 14 euros each one. Any aditional idea also to do an only power supplier for the four cameras?

Thank you very much.

Best regards,

Juan José

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reyalp

14110

Re: Triggering 4 cameras from computer

« Reply #1 on: 08 / July / 2012, 20:45:21 »

Hi,

There are two was you can trigger a camera from the computer. You can use the PTP extension to control with software on a PC http://chdk.wikia.com/wiki/PTP_Extension
The chdkptp client has some experimental code for controlling multiple cameras, however you should expect to do some programming to get it fully working for your application.

Alternately, with some simple electronics, you can use the http://chdk.wikia.com/wiki/USB_Shutter_Remote control the cameras.

Both methods have been used with some success by members of the forum.

You cannot power the cameras from USB. Presumably if you got a power supply with the right voltage and sufficient capacity, you could run all the cameras off of it.

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jfonfria

7

Re: Triggering 4 cameras from computer

« Reply #2 on: 09 / July / 2012, 05:52:12 »

Dear Reyalp,

Thank you very much for your information. For tests that I'm going to perform in this moment, it is very usefull. In a future (I want to do control cameras and measurement devices also) I will ask to you for more information about programation.

Only one aditional question: in the circuit that you send me in attach, wires 2 and 3 have to be desconected? And could I connect four USB-wires to a same ON/OFF button and battery?

Thank you very much. Regards,

Juan José

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Microfunguy

4037

Re: Triggering 4 cameras from computer

« Reply #3 on: 09 / July / 2012, 07:32:09 »

Quote from: jfonfria on 09 / July / 2012, 05:52:12

wires 2 and 3 have to be desconected?

Yes.

Quote

could I connect four USB-wires to a same ON/OFF button and battery?

Yes, or buy this switch and an extension unit and you can control up to twelve cameras :-

http://www.gentles.ltd.uk/gentstereo/sdm.htm

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jfonfria

7

Re: Triggering 4 cameras from computer

« Reply #4 on: 10 / July / 2012, 08:16:15 »

Dear Microfunguy,

Thank you very much. I sent them a email for give me a solution and a cotitazion. Only one question: it could be possible to connect the four cameras by a hub to the computer, and open four PTPCamGui applications, one for each camera? Thank you very much.

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reyalp

14110

Re: Triggering 4 cameras from computer

« Reply #5 on: 10 / July / 2012, 12:47:40 »

Quote from: jfonfria on 10 / July / 2012, 08:16:15

Thank you very much. I sent them a email for give me a solution and a cotitazion. Only one question: it could be possible to connect the four cameras by a hub to the computer, and open four PTPCamGui applications, one for each camera? Thank you very much.

The solution using the USB remote (which is what Microfunguy linked) is not a a full USB connection. With the USB remote the camera just senses the +5v on the USB connector. To control this from a PC, you'd need some hardware interface to turn this on and off.

To use ptpcamgui or other PTP software, you have to use the PTP Extension, not USB remote. In that case, you can use a hub. I'm not sure about ptpcamgui, but you can run multiple PTP client applications. You have to be careful because some operations could cause other instances to disconnect. As mentioned earlier, you can also control multiple cameras from a sign instance of chdkptp, but this can currently only be done from Lua code, so you'd need to do some programming to get a proper user interface.

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Don't forget what the H stands for.

msl

1280
A720 IS, SX220 HS 1.01a

Re: Triggering 4 cameras from computer

« Reply #6 on: 10 / July / 2012, 13:02:22 »

ptpCamGui is not suitable. A function to connect multiple cameras has been tested temporarily, but this feature was too unstable and was removed.

msl

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