Intervalometer project: moving beyond prototyping

Good evening, all. I got my deliveries (about 4 in all) of all my Arduino-related stuff a couple of weeks ago. I've progressed beyond the blinking LED tutorials and managed to interface the Arduino with my Canon 40D, three buttons, and an LCD display to come up with a simple, configurable intervalometer (timer) for time-lapse photography. The basic components I'm using so far are a Diecimila, a 16x2 LCD I picked up from eBay, two 4N28 optocouplers, a 3.5mm stereo headphone jack, and the afore-mentioned buttons. I've implemented a pretty clean menu interface for configuring a half-dozen parameters or so, and just have to store that into EEPROM to pretty much call the software part of this "done".

I'm starting to get stuck with how to move this beyond the breadboard stage, however. Are there any tutorials, threads, or other sources of information on how to go about stuffing this thing into a project box? I need a box which will fit my display (the biggest part, at about 3.5 x 1.5 x 0.5 inches), and I also need to figure out how to source and mount the pushbuttons and headphone jack so that they'll be accessible through the enclosure. Every time I think I hit on something in the Jameco catalog, I end up adrift in a sea of choices, none of which seem to really fit my needs.

My other remaining hurdle is how to power it. My power requirements are relatively low: I only need to power essentially four LEDs (two for status, two as part of the optocoupler) and the display. I'd like to be able to use AA NiMH batteries, but at 1.2v each, I need a sizeable stack of them before I can come up to the 5v required by the Arduino. My searches for DC-DC ICs that can crank up the voltage for one or two AA batteries has come up empty so far.

I'd really appreciate any pointers anyone can give me! :slight_smile:

Here are 2 options for power -
5V DC to DC Step Up - VPack PCB - PRT-08290 - SparkFun Electronics.
and Kits & Projects, MintyBoost Products Category on Adafruit Industries

Are you going to put the Arduino board in the box ?

You could go for one of the small clone boards, like the Really Bare Bones Board or the Boarduino. This would reduce the size requirements considerably, the LCD would probably be the limiting factor.

As for the buttons, there are so many choises, you could mount them on a small PCB (or Veroboard) behind the frontpanl of your chosen enclosure, or directly in the frontpanel, depending on the type of button you choose. The same goes for the LED's.

Does your camera + other equipment have some kind of power you could tap into? this way you could avoid having seperate batteries for the timer. If such a voltage exists you might have to regulate it down to the voltage required by the Arduino board + LCD. But it would simplify things.

For the enclosure i would try to find soemthing as flat as possible, and from the very start try to find some kind of clamp or other attacment system to mount it on your other equipment. This kind of project frequently ends up, being attached with gaffer tape or something like that, whis in the long run is very annoying.

BroHogan, those are prefect. Thank you!

MikMo, I'm probably going to put the Atmega168 chip right on the board. The BBB and RBBB are possibilities, but I think that if I can handle soldering chips to the board that I could be able to also provide the most minimal configuration to support the AVR, and put it in a DIP socket so that I can reprogram it via the Arduino board if needed.

I don't think there's a way to tap into power from the camera, and I don't really want to do that, anyway. I haven't investigated to see what's available via the remote port wires I'm hacking into, but that doesn't seem like a very good idea (especially if I ever want anyone else to use it with their $1,000 camera...). I've also attempted to make it "sleep friendly", in that it will wake the camera if the camera is set to go to sleep after a certain period of time. I recently bought a small truckload of AA and AAA NiMH batteries for my PocketWizards and flash and want to try to re-use those. It looks like the step-up converters that BroHogan pointed me to could potentially operate off a single cell (but more likely at least two). Hrm, I wonder what kind of runtime I can get out of a lithium watch battery?

I do want to minimize the footprint of the enclosure as much as possible. My component list is very short: two 6-pin DIP optoisolators, maybe 10 resistors, and then the Arduino, of course. I should be able to pack that tightly under the LCD board. I'll probably start at Radio Shack to find the protoboards and boxes. I was disappointed to see how poor Jameco's site is at finding a suitable box, but I haven't gone beyond there yet.

Looking forward to see the finished timer :slight_smile:

Looking forward to see the finished timer :slight_smile:

Me too!!

What software/method are you using to convert the images to a movie? I've been having a hard time finding something decent.

What software/method are you using to convert the images to a movie? I've been having a hard time finding something decent.

I haven't really gotten that far, yet. :slight_smile: I've played with QuickTime and iMovie in the past for doing this, but I think iStopMotion (?) will do the job, as well.

I've also designed a digicam intervalometer. (see my sig.)

I chose to power it from an internal 9 volt battery, providing 5 volts through a low dropout regulator. (There are also external power provisions, with a regulator to provide camera power when running from an external 12 volt supply.)

Hantronix makes some nice miniature 16 x2 LCD modules. Sockets are available through Digikey.

Rather than try to fit an Arduino board into my (hypothetical) box, I've used a bare Arduino chip on my project board.

Although I haven't packaged my unit yet, the little Hantronix display and not using an Arduino board will let me build the unit into a box small enough to put into my gadget bag. I've located and obtained a suitable box, and might actually package this thing one winter weekend.

Good luck!


Hey, Tom! I've seen your AI-1 remote and it's very impressive. I thought about following your plans, but it seemed a little more complex than I want/need. In retrospect, I'm not sure my code is that much simpler, relatively speaking. I am fairly happy with my menu system, however. You can see my code in my public SVN repository.

I'm planning on going the same route as you with the Atmega chip: I'm just going to make it all part of my circuit. It looks like core functionality can be retained with just a crystal, provided you're doing your own power conversion. I want to go with AA or AAA batteries because I've already got a bunch of NiMH cells, and my charger won't work with a 9v battery. Hopefully the Maxim chip mentioned above will do the trick.

This (eBay listing) is the display I got for $5 plus shipping. If the Hantronix display I saw on Jameco is the same as yours, they're the same size, but it adds a backlight (and is half the cost ;)). I'm planning on putting a timer onto the backlight so I'm not drawing juice from it all the time. I've also added contrast control to my menu; not sure how often that'll have to be tweaked...