Hi
I am a young photographer and I want to build a countdown timer circuit that uses 7 segment displays to show the time countdown.
I also want to use three buttons, one to add minutes, the other to add seconds to the countdown and the final button to start the countdown. Which displays the remaining mins/secs on the displays. When the countdown is started a switch needs to be closed and when finished it needs to open again.
I am basically trying to build a programable shutter button so I can take extremely long exposures.
I have a basic understanding of electronics but need help with the code and bringing them both together.
Circuit diagrams and code would be very greatfully received.
Many Thanks
Jack
Go to the learning section, and the playground, and search for Stopwatch.
Do some reading, then come back and ask your question again.
What you ask about is fairly simple. The only 'challenge' is your display - are you talking little 1/2" to 1" type displays? Those can be easily controlled from the arduino, or you could add an external chip to control them and just send a serial message to a controller chip, or many variations in between (such as drive the elements from a higher current shift register like a 74AC299PC from Newark, shift register good for 24mA LED current). You could have individual displays, or find one with 4 digits grouped together. You could also add a couple of discrete LEDs to indicate "armed state", "shutter open", etc.
Jack, you might check this out: http://yourduino.com/camera-control.htm
The code and info: http://www.mindspring.com/~tom2000/Projects/AI-1_Remote/AI-1_Remote.html
This will even run on a 168 and I am looking at adding stuff like RF remote, camera motion control...
Jack,
This is an interesting project and I am sure you will learn a lot. One thing you need to figure out is how to trigger the shutter. Some cameras have an Infra Red facility - My Olympus SLR does. So you will need to look at using an IR LED turned on/off by the Arduino. I have a similar project in mind for my new Olympus E-PL1 which, alas, lacks any form of remote control and an old school cable release will not screw into the shutter button. So I'll be looking at a small solenoid that I can trigger from a pin on the Arduino via a transistor to manage the extra current. (Does anyone know where I can source one of these in the UK? -the solenoid not the transistor).
Once you get the timer function working you can add the functionality for an intervalveometer (A programmable shutter release that can allow you to take many pictures at intervals you program). There are plenty of examples of these here....
Good Luck,
Steve