Scott's Blog

Here's the camera taking images of the evening sky.  I stopped it when it got so dark that it was taking nearly 4 seconds of exposure per shot. Here's the movie made at 25 fps with 900 photos at 5 second intervals.

I was finally able to track down a 2mm stereo plug here in Belo Horizonte ( Eletronica Guarani ) so I can remotely control my Canon SLR from the Arduino. It uses two SPDT relay switches , one for the shutter and one for focus.  The way it's setup, there's no way I can cross the wires and hurt my camera, even after a few beers.  In the photo the black wire is hooked to ground and the blue wire to pin 12 on the Arduino (or Seeeduino in my case).  So far I've only used the shutter and have left auto-focus off. Here's my first attempt of a timelapse movie with this setup: You'll find the code here . This page helped me figure out to hook-up the plug. Making the movie is a little tricky on Linux.  First you'll need to installed GraphicsMagick (a faster version of ImageMagick): sudo aptitude install graphicsmagick Then you'll need to downloaded and compile from source mpeg2encode to that it can do the conversion to mpeg (this doesn't come includ...

The idea this weekend was to setup the sonar with the Arduino so that I can get a shot of the Siriemas  that pass daily at the farm, or maybe a hummingbird. Well that didn't work out so well, turns out that the sonar is affected by the wind. Adding a bit of hysteresis to the code , fixed it for the most part. I used lua to program the camera, except that it looks like there some issues with it and my Canon SD450.  Calling get_shooting() repeatedly causes problems, for example. I got my intervalometer  code  to work correctly only after removing that test.  Here's some timelapse photography that did work.

This weekend I played with my Canon PowerShot SD450  (aka IXUS 55) and the  CHDK  along with the Arduino and the MaxBotix MaxSonar  LV-EZ1 .  The idea is to automatically take pictures when an object moves into frame. Part of the job involved hacking a USB cable to hook up to the Arduino which I promptly did, as you can see below. Unfortunately, I was supposed to hack a Mini-USB cable (of which I have a dozen) and instead hacked my (only) Micro-USB cable (oops). The end I soldered two break away headers and then encased the whole thing with hot glue. Here's the setup. You can see the sonar on the right.  I soldered a female header to it instead of soldering wires directly to the board.  The hacked USB cable is connected to ground and pin 13.  For the sonar I've plugged it into Ground, 5V, and pin 7. You may also note that I'm not using the AN (analog) pin on the MaxSonar, but instead the PW (pulse width) pin, unlike most code I saw on th...

I bought the Canon Rebel XSi (aka EOS 450D) digital SLR and have taken some pictures . After using the typical consumer compact camera (like the Canon Powershot SD ) for a a few years using these modern digital SLRs is like going from a Corolla to a Porshe. The speed a which it can focus and shoot is incredible, I could depress the button for 4 hours and take pictures at 3.5 pictures per second until the battery runs out. I also got a 8 gig memory card (only about $20.00 these days) and am thrilled that I can take more than a 1000 pictures with no problems. I tried my wifes older Canon EOS film SLR lenses and they worked flawlessly. I was surprised that the image I saw in the viewfinder was the same as what came out in the final image as well. Having the large 3" LCD means I can reliably review my image and make decisions about what to delete which I used to always do on the computer. I've been waiting for years to buy a digital SLR but it had hovered around a $1000 for...