I built an Arduino-based intervalometer for my Nikon D40 because it has no direct connection via cable and there are no commercially Intervalometer at now exception to the one mounted on a battery grip, but has a limit of 90 minutes of operation.
The circuit is very simple
-1 Hitachi HD44780 compatible LCD 16x2
i've buyed this to:
like this one or green or more row as you like.
-2 Linear potentiometers
-2 On / Off switch
-1 Button to PCB
-1 Protoboard shield
if you want to remove your Arduino sometime
-1 Plastic box for electrical equipment
Step 1: Connect your Display LCD and component
-Connect one potentiometer to pin 3 of the display like as you can see in the tutorial above to have contrast control, the other potentiometer is necessary to connect to A2 analogic pin of Arduino, we will use it to read an analogic input 0-1023 used to transform in the interval chosen inside the Arduino sketch.
-Connect on on/off switch to pin 15 of display, this is for a backlight turn off to cheep battery power (my timelapse are about 5 h of camera shot)
-Connect another switch that will use to power supply. About power you can choose different method to supply, USB direct connection if you are near the camera, one 9v battery connected directly to Arduino.
My goals now is to realize a power supply like show in this useful instructables:
-Connect one micro button and a resistor to Arduino pin reset to bring out the command.
-At the end connect on IR LED to pin 13 and one resistor (100 ohm)
Step 2: Insert component on the box
Do the same after you have drilled some holes with switch and the knobs of potentiometers.
Position the led where you want trought a led holder, and cut a small square to leave free the Arduino usb port (see the video)
Step 3: Upload the sketch
Copy and install the sketch, of course you can change the words as you like, but respect the space.
Set the Nikon in remote shooting control and position it on a tripod
Keep the IR LED in front or 90° of camera led.
Set time intervall (depends which type of timelapse you wanna do, but this is another instructables..)