As a an avid photographer, I carry two things on me constantly - my phone and my camera. Once I discovered there was a way for me to use my iPhone as a camera remote with the DSLRbot app, I knew I could easily build my own remote trigger for my DSLR with Radio Shack parts.
Step 1: Materials
Step 2: File Down the LEDs
To get the LEDs to be flush with each other, I filed down one of the sides one each one. Holding the LED so that the positive lead was to the right, I ground down about an eighth inch of material from the LED using a metal file.
Step 3: Glue the LEDs Together
I used a quick-setting two-part epoxy to glue the two filed down sides together. You just need a little bit, it goes a long way.
To mix the epoxy, gently squeeze out of the tube on to a piece of wood or cardbord. Then, snip the end of a popsicle stick or coffee stir to thoroughly mix both parts of the epoxy together.
Gently apply a small amount of epoxy to the LEDs' filed down edges, and allow to sit for 30 minutes.
The LED's leads are wired in reverse parallel, so you need to file down the same side on each LED. The long positive lead from one LED must be wired to the short negative lead of the other LED, and vice versa. Please see the schematic attached to this step.
Step 4: Prepare the Headphone Jack
Take the sleeve off of the headphone jack by unscrewing it, and then snip the end off where the cord comes out of. Using the metal file again, I ground down the end I just snipped off to make it even again. Lastly, I took a box-cutter, and split it in half to accommodate for the LEDs I would be putting in there.
Step 5: Solder LEDs to Eachother, and to the Headphone Jack.
After the epoxy had set, I bent the leads of each LED towards each other, then solder them together at a very high spot close to the plastic dome of the LED. After I soldered them to each other I trimmed a lead from each end, so I effectively had two leads for two LEDs (instead of four leads). I then threaded the leads through the holes of the stereo jack, and soldered them into place.
Step 6: Re-Sleeve the Headphone Plug With Heat Shrink.
I took the cut plastic casing for the plug and re-sleeved the stereo connector with it. After the metal components had the original plastic on it, there was still a gap. I cut a small piece of 1" heat shrink, and slid it around the original plastic. There are many ways to seal heat-shrink, I personally like doing it with the barrel of a soldering iron. Others will tell you to do it with a heat-gun, and I have even seen it done with butane lighters.
Step 7: Get the App and Take Pictures.
There is an app available for iPhone called DSLRbot. With this app you are able to turn your iPhone into an intervolometer, a wireless remote, and even a shutter release for bulb modes on Canon and Nikon cameras. As long as your camera has an infrared module long on the front of it, and you can be line-of-sight to the camera from your iPhone, this app is extremely handy.