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Open Camera Controller >> OCC Developer Zone >> alternate hardware for mp3 or smartphone interface
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Message started by grrmuzzigrr on 04/04/11 at 06:16:02

Title: alternate hardware for mp3 or smartphone interface
Post by grrmuzzigrr on 04/04/11 at 06:16:02
I came up with an alternate hardware design that should allow anything with an headphone jack and the ability to playback mp3's to work as a camera controller. So ipods, iphones, android phones, and the new variants of the DS (DSi, 3DS) should work.

I call it the Minty Camera Controller. I built it to fit inside an antoids mint tin. I originally thought it would run off coin cells but I didn't look into battery life on those.  (could be short, depending on length of exposures)  It should still fit in an altoids tin with 4x AAA batteries in a homemade battery pack (just wire and tape) or an external enclosed plastic battery pack about 60% the size of the tin can be found easily.

it has a stereo input and detects tones on the left and right channel to operate the full shutter and half shutter. when a tone is detected on a channel it will close the appropriate circuit for the duration of the tone.

With a mp3 player you will need the exposures pre encoded. I plan on having a library of commonly used bracket exposure sequences set up, along with a few different intervals (silent tracks). Using playlists and repeat modes on the mp3 player you should be able to shoot a custom interval repeating bracket sequence.

For interactive on the fly/in the field adjustment of settings, I assume an iOS, or Android app could be easily programed - Just needs to generate a specific tone to trigger the camera. I'm not sure how the existing OCC software works (I know you have the programed Atmega chip in the hardware) but using the audio out on the DS I assume would be easy.

So far, on my Rebel XSi, the fastest, reliable bulb exposure I have achieved is 1/10 sec with mirror lock up enabled, and 1/5 or 1/4 with mirror lock up disabled. I haven't really done too much testing yet.

Haven't had time to draw up a schematic but I used this circuit as the base of my circuit. (x2 so you have 2 channels) ending in a optocoupler to interface with the camera. 

youtube demo
http://www.youtube.com/watch?v=MsrScqgk49c

http://farm6.static.flickr.com/5133/5587294543_04db8b8b6c.jpgIMG_7072 by grrmuzzigrr, on Flickr

Title: Re: alternate hardware for mp3 or smartphone interface
Post by Blochi on 04/04/11 at 07:54:05
Hey, that is a brilliant idea!

Is the rest of the board derivative - does that have the same frankensteined camera plug?

If you can filter the audio input to listen only to a particular frequency, like a particular base or pulse, my buddy is a DubStep DJ and could mix some cool tracks around these tones. Then you had "Bracketing by Album" and instantly a viral sensation! ;)


Title: Re: alternate hardware for mp3 or smartphone interface
Post by Steve Chapman on 04/11/11 at 23:54:22
Neat stuff. We also have a DTMF OCC reference design that can detect individual frequencies, FYI.

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