Revenki's photos with the keyword: Arduino

The "production" version of the Arduino shield stack used to run the camera dolly. In order to fit in a reasonable sized box, I combined five functions into one: the limit switches from the dolly, the camera interface, the button interface for controlling the electronics, the interface for the display, and a piezo beeper. After taking this picture, I ended up having to rewire the optoisolators (middle top) and troubleshoot a crossed wire in the display header (lower left), and added the headers in the upper right for the lines to the camera remote and limit switch panel jacks. Not bad. I was expecting more than two screwups, and it was really only one (the display header) when you consider all the inexplicable trouble I've had with optoisolators - I figured those would turn out to be wired wrong no matter what I did, and I was right. Now to build the box, and finish the software.

The "production" version of the Arduino shield stack used to run the camera dolly. On the bottom of the stack is an Arduino Mega 2650. Then comes the hand-made card with five different circuits: a resistor ladder and socket for the controller's input buttons, the breakout and socket for the display harness, the OR-gate and resistor network for the limit switches, the opto-isolators for driving the camera via wired remote, and a little piezo beeper. Finally comes the Rugged stepper motor controller card. 12V input power drives the dolly via the green connector on the right (the stepper card helpfully feeds power to everything else). The little pot on the left side of the middle card controls the contrast on the display, whose harness plugs into the adjacent black header. Everything is connectorized, due to lessons learned from the lightning trigger project - every switch, plug, etc. can be dismantled from it's associated board either by pulling a connector out or loosening a screw post. This came in handy when I got the first copy of the faceplate together and discovered it wouldn't fit in the box I'd bought - had everything not been connectorized, I'd have had to tediously de-solder everything, breaking the tested configuration and requiring it all to be tested again after it was reassembled on the new faceplate. (A trick I learned working on rockets. Don't ever say your defense procurement dollars are totally wasted.)

Ready to go. Just needs the programming, which is mostly done.

As my supplies of profanity were rapidly running out, I finally got the thing packaged. And wonder of wonders, when I ran the test program, all of the switches and sensors and LED colors worked, despite the abuse involved in shoehorning everything into the box. Note the stacked washers under what was going to be a sleek and discreet surface-mounted arming button. This is what I get for doing test fits without the Arduino mounted - one corner just barely interfered with the body of the switch. Two nylon washers, one cc of epoxy, and much carving with the dremel took care of that last fit-up hiccup. Just underneath, you can see the hot-shoe mount. I foolishly expected that *that* would be the hard part of this project.

The unit is based around an Arduino Micro microcontroller, and uses two MC3041 optoisolators to drive the focus and shutter lines for the Nikons (via commonly available camera-specific cords from Aputure). All very simple. Until you try to fit it all into a tiny box that will mount on the hot shoe. As it went together, the unit sans enclosure took on the unpleasant look and feel of an electronic squid-like creature. Here it is, ready for its first test fit in the housing. After which I would expend a great deal more profanity in the process of rewiring two of the slide switches and the remote jack. The loose wires are for the indicator light, which I knew better than to try to wire up before getting everything else fit.

Not shown are the RGB LED and associated current-limiting resistors I switched to late in the day, the washers I had to add under the trigger button, and the fine-gauge (26?) wire I had to switch to in order to fit everything in. Oh, and copious heat-shrink tubing. And no, I didn't recognize the need to change the wire gauge until after I'd had all the switches pigtailed and test fit into the box.

The results of three hours of work with a drill, a dremel, hand files, and profanity. Putting the 9V battery inside the case meant replacing the countersunk screws that came with the box with finger-turnable socket-head cap screws. Unfortunately, being #4 screws, they aren't very finger-turnable and will need to be replaced with thumbscrews or something in the future. All that's missing here is the tiny poke-hole for the reset button, which I added after the unit was built up (needed to know for sure where the Arduino button ended up).

I think I needed a box about 5mm larger in all three dimensions. The switch positions were dictated by the limited space around the 9V battery, which itself just barely fits under the cover. This is what happens when you see all those extra Arduino pins going unused and decide to add functionality.

A test assembly of the in-work motion control dolly. Not everything is bolted down tightly yet, this was just to see if it would all go together, and when it did, if it would run. And run it did. Took a little more power to drive the carriage than I thought it would, but the motor shield on the Arduino didn't even get noticeably above room temperature (unlike the other one whose bridge I burned out with no load on the motor -- oops). The Delrin coupling seems to be a tiny bit off-centered, but it's just a fit-up problem -- close enough to proceed with finishing the assorted aluminum bits and wiring up the limit switches.