How can hack a camera to a sequenciel shot of picture

Dear all

We are going to build a windtunnel and we would like to have a small camera on the top of a towel.
We need that canera take automaticaly a picture each x hours. May be each 4 hours.

One of my colleague (who is not here to help me) has built a circuit with arduino (I am not wrong) wich send a signal to the canera and shot a picture.

Some has a idea, how I could do that with a arduino, or something esle?
Any ideas?

Cheers

Connect a servo to the Arduino. Rotate the servo to press the shutter release. Rotate back. No physical connections needed to your mystery camera.

I got to ask - why is the camera on a towel?
Won't the towel blow away?

I think the first thing to sort out is what sort of camera you are going to use. The Arduino can provide an electrical trigger, but it won't do anything with the picture, so conceptually all it's doing is pushing the button for you - you have to deal with anything else that needs to happen afterwards such as retrieving the picture or saving it somewhere.

If you decide that you can get away with a conventional web cam, you could connect it directly or wirelessly to a PC and use the PC to take the picture according to whatever schedule you want. There is a ton of free software to do that sort of thing.

Excuse me for my english.

It's not a towel, but a tower. The camera should be at about 10m height.

Hope this isn't some covert nuclear testing deal, etc. If you are using a conventional digital camera (like a DLSR) you need a 'cable release' connection. This is pretty simple, a two wire connector. All you need to do is to 'trigger' (short circuit) the connection. That will do the same thing as pressing the button. Buy an Arduino UNO and run the 'blink' example. Change the delay setting right below 'digitalWrite(led, HIGH'); to 14400000. That will give you a trigger every 4 hours between pin 13 and ground on the Arduino.