Work has been getting in the way of hacking for the last week or so and I’ve still not had chance to get out with the camera. Hopefully this weekend.
The main programming challenge for the intervalometer was getting a simple menu working with just 2 buttons and a 16×2 character LCD. I’ve already said that with hindsight I’d go for a 3-button interface, so I’m not going to go into great detail about how this works.
The next problem came when I had built the circuit into a box and tried using it with the camera. While testing it had been a bit unreliable, but I put that down to odd angles, clutter on the desk, wishful thinking, whatever… However, once in the box I soon discovered that it was just unreliable. I suspected that the IR signal was inaccurate but how to tell. By this time I’d bought a second arduino, this time a Mega ADK (Android fun coming soon). So I added an IR detector and using the code from the tutorial on www.ladyada.net I could see the on off times of the Nikon remote control and my intervalometer. There were a few discrepancies and some fiddling with values got my signal much closer. If you compare my code from the previous post to that in the tutorial you can see the changes.
There isn’t an error in the original code, and its values should work in theory. However in practice it looks tolerances in the clock speed of the arduino means that the arduino Delay() ad Milli() functions are not accurate. So if you follow this design you will also need to adjust the timings to get reliable firing of the shutter. So you may also need 2 arduinos to get this working.
My next project is underway. It will be a robot arm using 7 servos. At this point I’m cutting parts from 4mm acrylic using a CNC mill, unfortunately my attempt t prepare files for the CNC machine with Open Source softare has failed and I have reverted to using a well known CAD program and a commercial CAM program I have been using for a couple of years.
I’m also think about other uses for the intervalometer. For example attaching a motion detector, or sound detector could allow me to set up to do some wildlife photography, or just caputure people entering and leaving a building. I’d love to hear other suggestions of what could be done with a camera and an automated IR remote control shutter.
On the plus side my Ubunto machine upgraded to 11.10 Oneiric Ocelot this week without a hitch and just one restart. That’s not something I’ve ever been able to say about upgrading Windows!