Panduino Closed Loop possible?  

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solock
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Panduino Closed Loop possible?

by solock » Mon May 03, 2010 5:35 pm

So i was thinking that the panduino option (using the micromaestro servo board) has some empty channels, and they are valid inputs as well as drives.

What Im thinking is would it be possible to monitor the hot shoe for the camera to trigger so that papywizard can confirm that a photo was actually taken??

Missing shots with my merlin or panoduino are my only real concerns. When a bad cable gets you, 500 shots later is the wrong time to figure this out...
Canon 50D, 20D, 1D MKII
Tok 10-17FishEye,Canon 10-22, 24-70 2.8, 50 1.4, 70-200 2.8IS, 300 2.8,1.4x,2.0x
303SPH, Panosaurus, Merlin+Parallax Bluetooth+USB to PC and Nokia N810

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fma38
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by fma38 » Mon May 03, 2010 6:01 pm

Yes, it is possible to monitor the hot shoe, as long as you build the correct cirrcuit. I can modify the plugin to wait for the contact.

As the µ-maestro input is analog, I think to add 2 params to define the high and low levels. And a simple 'Wait for hotshoe contact' checkbox.

Let me know if you need something else.
Frédéric

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by panoguy » Thu May 06, 2010 11:23 pm

I just implemented this on my controller and it works like a charm.
I bought a simple hot shoe cable and used two contacts (ground and x) to trigger an interrupt on my controller.
Within the interrupt routine I'm setting a flag and check if it has been set after each trigger command.
If the flag has been set, I'm resetting the remaining recording time to 0 and move the head to the next position.
The flash synch must be set to second curtain to be sure to move the head at the right time.
If the flag has not been set I'm waiting for the user to confirm.

Next step would be to implement this feature into Papywizard
and adding one additional command into the plugin;-)

Be aware the hot shoe synch time is very short, so your controller needs to be able to check the status within the right time.
Means you will have to use a low level interrupt.
Last edited by panoguy on Thu May 06, 2010 11:30 pm, edited 1 time in total.

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fma38
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by fma38 » Fri May 07, 2010 6:54 am

To implement this in Papywizard, it first needs a controller able to read this contact. I will make some tests with the µ-maestro, and if it works, I'll this feature to the Panoduino plugin.

I will also find a way to extend the width of the pulse.
Frédéric

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by panoguy » Sun May 09, 2010 7:10 pm

The easiest way to read the contact is to wire the hot shoe x contact to a interrupt pin of your AVR and Hot shoe ground to AVR ground. You don't need any additional circuit in between.
From a software / plugin point of view would it not be enough to respond to the
Set shutter contact state O<axis><state>
with another value as long the camera did not take the picture?
i.e. instead of response =\r
send =0\r
as long the picture is not confirmed, and after the picture has been confirmed send the default response =\r

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by fma38 » Mon May 10, 2010 9:41 pm

Let me think about it...
Frédéric

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by panoguy » Mon Jun 07, 2010 5:12 pm

After further investigation of this option with different camera brands I found out that Canon uses a different method to trigger the flash compared to my Olympus camera.
Olympus works perfectly if you set the flash synchronization on second curtain, this triggers the hot shoe 'at the end' of the exposure and the controller can assume the last picture was taken successfully.
Canon triggers the flash contact during the entire time of the exposure time.
This means in the controller must be able to detect the end of the synch pulse, in AVR terms the external interrupt must be activated on the rising and/or falling edge of the synch pulse.


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