problem with control camera by RC

Emilie FNS

« on: 20 / May / 2009, 04:32:10 »

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Hi everybody,

I am new in the CHDK forum.
I have bought an IXUS860/SD870 and I want to control it when it is on a helicopter. I have a radio receiver and I connect the USB port from the camera with a servo channel of the receiver.
I load the right CHDK firmware and I test the basic script for remote control. I want to take photo when I use a switch on the remote.

@title Remote Control

:loop
wait_click 1
is_key k "remote"
if k=1 then shoot
goto "loop"

end

But it doesn't work, I can't communicate by the USB port.
Where I am wrong?
How can I do that?

I really need help.

Thanks.

Emilie

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Microfunguy

4037

Re: problem with control camera by RC

« Reply #1 on: 20 / May / 2009, 04:53:18 »

Do you have any electronics (such as the gentLED devices) attached to the receiver output ?

The normal servo pulses are too short to detect.

David

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Emilie FNS

Re: problem with control camera by RC

« Reply #2 on: 20 / May / 2009, 05:11:07 »

Hi David,

thank you for your reply.
I don't understand what you mean by gentLED devices. I have made the "gentled CHDK for Canon cameras" myself. Is that what you think?
Or is it the "gentled SHUTTER"?

I want to take photos but I also want to control zoom and select video/photo mode. I have 4 servo channels on my receiver.

Emilie

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Microfunguy

4037

Re: problem with control camera by RC

« Reply #3 on: 20 / May / 2009, 05:53:02 »

Hi Emile.

Can I ask again, are you connecting the receiver output directly to the USb ?

If not, how are you connecting it ?

Is it a standard receiver that generates one to two msec pulses every 20 msec ?

David

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Emilie FNS

Re: problem with control camera by RC

« Reply #4 on: 20 / May / 2009, 07:38:14 »

Hi,

Yes I connect the output of the receiver directly to the USB.
It is a standard receiver (PCM) and it generates 1 pulse every 20ms.

Emilie

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Microfunguy

4037

Re: problem with control camera by RC

« Reply #5 on: 20 / May / 2009, 07:54:27 »

That will not work.
The pulses are too short to detect.
Also, you want pulses of varying width.

You need the gentLED device or similar.

David

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Emilie FNS

Re: problem with control camera by RC

« Reply #6 on: 20 / May / 2009, 08:05:12 »

Do you know what kind of electronic there is on the gentLED device?
What do I need to make it work?

Thanks.

Emilie

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Microfunguy

4037

Re: problem with control camera by RC

« Reply #7 on: 20 / May / 2009, 09:01:41 »

See details of gentLED CHDK and CHDK2 here.
The first one generates a single pulse to operate the shutter, the second one generates pulses of varying width that can be used with a script to operate zoom, etc.

David

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Emilie FNS

Re: problem with control camera by RC

« Reply #8 on: 22 / May / 2009, 05:57:03 »

Hi David,

I have seen details of gentled CHDK2 but I don't really understand how that works.
A PPM trame is 20 ms and a normal pulse is 1,5ms and vary between 1ms and 2ms. And the script tests the return value of get_usb_power but this value is between 4 and and 19.
How is it possible? Maybe a microcontroler does that?

Do you know how that works?

Thanks.

Emilie

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Microfunguy

4037

Re: problem with control camera by RC

« Reply #9 on: 22 / May / 2009, 08:40:23 »

Quote from: Emilie FNS on 22 / May / 2009, 05:57:03

Maybe a microcontroler does that?
Do you know how that works?

Yes.

With the gentLED CHDK2, it outputs pulses 30, 60, 90, 120, 150 and 180 msec long.

With the ordinary gentLED CHDK, it outputs a 400 msec pulse.

The scripts you refer to were written by forum member 'Zeno'.

David

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