Getting Printed Circuit Boards Fabricated

Close Up Of Nano And BLEI’ve been making progress on the camera motion rig, but it is a not very portable mass of protoboards, wires, alligator clips, and bench-top power supplies.  It works, but it took me 15 minutes just to move it from one table to another.  At this point in a project, you have a few options. You can solder the components onto some perfboard and direct wire up all the connections.  That’s nice and immediate and makes it fairly rugged, but what you end up with is an ugly one-off board. Another option is to make a printed circuit board.  I’ve been etching them since the days of rub off letters/pads/traces, when I’d spend hours with an Exact-o knife and a rubbing stylus. Then for years, I used various toner transfer methods.  These methods let you print your design out on a laser printer, and then transfer the toner onto a copper clad board.  The toner acts as the resist and you etch away the rest of the copper.   Finally, a process where making the second board was a lot simpler than making the first one.  Still it was a pain because getting super clear transfers is a bit tricky, and aligning a second layer is a pain.  You spend a lot of time touching things up.   On the bright side, you can have the board the very same day.  I’ve been doing this for years, but the price of getting PCB’s made has been dropping and dropping.  So I finally decided to have the PCB’s for the camera control rig commercially made. Bluetooth Breakout Board FootprintI downloaded the free version of Eagle CAD. It lets you design boards with some limitations in terms of size and number of layers, but it seemed like it would work for me and, hey, it’s free.  Jeremy Blum has a nice set of video tutorials about the basics of Eagle CAD. My project is a little strange for a first attempt at a board because it is made up of a number of individual daughter boards.  There’s the Arduino Nano, the Bluetooth Break Out Board, and the stepper motor driver board.  Instead of starting by plopping down standard library components, I had to dive right in the deep end and start defining my own custom components.  Sparkfun has a bunch of good Eagle tutorials, including one that walked me though making my own part.  I spent the entire first evening just making the two missing devices.  That tutorial is really aimed at surface mount devices so I kind of had to wing the though hole part. Stepper Motor Driver FootprintEvery device has a symbol which is what shows up in the schematic, and one or more packages which match the physical shape of the device.  So for example a 555 timer chip has a single schematic symbol, but then can come in a tiny surface mount package, or a much bigger through hole version.  I was so exited when I finally got to the stage of being able to plop down my three main components and wire them together. On the second night I wired up the rest of the schematic.  That would normally be fast, but as you add components you have to always pick exactly which physical component you’re going to use.  It’s not just 100uF Capacitor, it’s a 100uF Capacitor with radial 3.5mm though hole pads and 8mm spacing.  Thankfully I was only using one resistor type, two types of capacitors, and two kinds of connectors.  So it took a while, but not crazy amount of additional time.  I think onece you have sort of built up a arsenal of devices you tend to use in projects that part will be much faster and less painful.

Screen Shot 2014-05-10 at 8.52.03 PM

Final Schematic

By the end of that evening I had wired everything up.  I noticed I still had some unused Arduino pins.  So I added a tri color status led, and a voltage divider so I could monitor the 12 volt supply in case it was being driven from a battery.  That way  I could support a low battery warnings, etc.  I also pushed the last few pins out to an aux port so I could add things like an external trigger button or jog knob later if needed.  Then I was ready to take a stab at routing the board.

Screen Shot 2014-05-10 at 9.24.56 PM

Footprint Problems

It was then that I saw various problems with my hand built parts.  I’d manually put holes though the pads which was redundant and was also causing an exclusion zone around those pins.  My ground plane was avoiding those pins like the plage.   Heck even the Nano part lib I’d downloaded had to have the corner dill holes removed. Also my extensive naming of things had really cluttered up my silk screen layer, and Eagle’s Smash Part command which lets you move the name/value around independently wouldn’t let me move those silk screens around.  *sigh* Screen Shot 2014-05-10 at 8.54.52 PMThe third night I spent reworking my custom devices, beefing up the various power lines,  fiddling around with labels, adding holes for mounting screws, and being generally anal retentive.  I spent a while trying to use Net Classes so the auto router would beef up the supply lines on it’s own, but for some reason it just was not having any effect.  I used the RIPUP; command a lot during that period.  It rips up all the routing on the board.  In the end there were only a few short runs that needed to be really beefy so I just routed them by hand. Ok so the board was mostly ready to go.  Now I had to get the thing built.  You can get Eagle to export GERBER files which define the various layers, have separate files for the layers, holes, solder masks, etc.  All the files need to have the right names and file extensions.  It’s all very fiddly.  Thankfully there are CAM job files you can download that will take various layers in Eagle and spit out a pile of properly named GERBER files.  So it’s a mostly automated process.   Then you zip those files into a single file and you’re ready to try sending them to some board manufacturers.  Jeremy Blum’s third video goes over doing this, and he has a Job file you can use.  His third video has a lot of tedious “putting together a bill of materials” section.  That’s probably the only really bouring thing in his otherwise awesome videos.  If you already know how to select parts (which you practially had to do to decide on parts for your layout) you can skip the middle third of that video. Lady Ada has a page comparing the various manufacturers. OSH Park Board PreviewI decided to try OSH Park first.  Just because I liked the sound of $5 a square inch for three boards and free shipping.  For small boards that seemed ideal.  It turned out all that fiddling around making GERBER files and CAM job messiness was totally unnecessary.  OSH Park takes Eagle board files, and a few seconds later you’re looking at beautifully rendered views of the various layers of your board.  Their boards have both top and bottom silk screens and are purple with gold plated pads.  So swanky.  They quoted me $29 for three boards.  I was so swept away by the simplicity and the nice looking layers that I just fired it off.   I was so excited.  A few minutes later I realized I hadn’t done the one test I had really wanted to do.  Printing out a scale version of the pads and making sure I had all the spacings correct on my home brew parts.  It was late at night at this point but I just HAD to know.   I wasn’t going to sleep well wondering if I’d have to wait 12 days to get 3 pieces of unusable purple and gold junk. Sadly my laptop isn’t connected to a printer so I tried exporting to .pdf and emailing that to myself so I could print  in from our desktop machine.   When I printed it out the sizes where all screwed up.  Either everything was off, or the scale was getting fiddled.  Googling around it sounded like others were having scale problems with pdf’s.  So I saved the file as postscript.  Sent that to myself and then I had to figure out how to send a .ps file to a postscript printer from Windows 7.  You’d think that would be trivial, but you’d be wrong.  I ended up having to install both ghostscript and the gsview postscript viewer before I could finally print  it out.   By then it was well past 1am, but I just HAD to know.  This time it printed out properly.  The pin headers had the right spacing the Nano matched, but horror or horrors the stepper motor driver’s two rows of pins where one step too close together!

Stop the presses!

Thankfully OSH Park batches your job up with a bunch of others so I was able to get them to cancel my board without a hickup.  I’m sure I wasn’t making my best first impression with them.  Oops.  I got up early and reworked that part’s foot print for the second time.  I hand re-routed the power lines again, and soon  I was back looking at the awesome purple eye candy. Screen Shot 2014-05-10 at 8.57.53 PMWould I hit the Buy Button this time?  No.  This time I was a bit more catihous. I noticed that on the actual CAM output of the board they were cutting the ground planes into strips.  That probably helps cut down on eddy current noise or something, but there were a few places where I was depending on that plane to conduct the full motor current.  I decided to go back and direct draw a few fat lines in those areas.   Also there was a place where an important pad had copper removed around the corners to make it easier to solder.  Soldering to a full copper plane is a pain since it skins so much heat.   For this one important pad there were only two small tabs connecting it to the ground plane. I fattened that one up to .056mm hopefully striking a better balance between solderablity and current. New Wider Stance and Wide PadsI also realized that OSH Park includes a bottom silk screen that I hadn’t used at all because I didn’t want to pay for that.   I quickly moved a few notations down to the bottom just so the board would look nicer.  Bottom silk screens are nice because that’s often where you’re poking around with probes trying to trouble shoot things.  Well at least for through hole projects.  Now finally when I was scrutinizing those purple and gold lovelies rendered on the OSH Park site I decided to pull the pin.  There are two capacitor pads that I wish were a bit bigger.  I think they may be hard to solder, but I declare it good enough.  I also experimented with converting the stepper board from normal round pads to the old style wide pads.  This way I can compare solderability. That day we were going to a friends birthday party and Cheryl and I both wore purple and gold to celebrate my first board send off. Now I have to wait 12 days for the boards to show up.  What the heck will I do?  I guess I can try some more time lapses and maybe start work on the enclosure.  Apparently I’m also doing a  blog post.  So far I’ve been very happy with OSH Park.  Their upload and verification stuff is slick and simple.  Since I’m already using Eagle it really could not be easier.  They also let me cancel my one rouge order.  I tried uploading my project to Seeed Studio and their site seemed to be telling me that it would be $9 for 10 boards which has to be wrong but there was no detailed feedback about the order and I couldn’t tell what was wrong.  For prototyping I think OSH Park is worth it.  If  I get to a point where I want to make more than 3 boards I’ll have to try someone else.  Now I just have to hope I haven’t screwed anything else up.  Are the 12 days over yet!?


Make Time Lapse Candle Videos

Timing a Birthday CandleWhile waiting for my project’s Printed Circuit Boards to arrive, I decided I should try shooting some more time lapses.  I won’t be able to design the iPhone software until I get some more experience.  I wanted to figure out some sort of time lapse that wasn’t crazy long.  That way I wouldn’t have to worry as much about ambient light changes, and I could try out different things quickly. I picked up a pack of birthday candles at the super market.  How long does it take one of those puppies to burn down?

I timed one, and it came in around 15 minutes.  Perfect.  Now all I needed was a better background.  As nice as peg board and cobwebs are, they weren’t the best back drop for my first time lapse, so this time I went that extra mile. I put a rusty steel plate behind the scene, but I still had to cover the base of a lamp. I decided to use a lovely wooden cutting board that my uncle had made for us. Alright, the stage is set. I completed my first candle time lapse.  That one went ok.  I was pleased by how the spirals on the candle sides make them look a bit like the tops are spinning down.

Blue Candle Lost SequenceThe one downside to shooting time lapses involving fire is that you must have a fire extinguisher handy and keep an eye on them the whole time.  None of this “set it off and go to bed” crystal growing luxury. One mistake I made was that I lit the candle with a match and accidentally clonked the candle while I was doing it.  For my next shot, I wanted to set up a bunch of candles and light them incrementally.  I rushed to the corner store and bought one of those butane BBQ lighters.  Now I was ready.  My first shot had been a bit short because the candle didn’t burn all the way down before the preprogrammed time lapse ended.  I guess my 15 minute test included a little bit of me blowing on the candle, which really shortens the burning time because it melts extra wax.  Also, this time I was going to be lighting them incrementally.  Best not to have it run too short, so I switched to a 28-minute duration.  I used the stopwatch on my phone so I could light the candles in 30-second increments.

I really like the idea of performance time lapse.  It’s kind of fun dodging in and out of scene between camera shots.  After 28 minutes of watching the candles burn, I rushed inside to squeeze all those stills into a movie.  OH NO!  This time there were no frames on the SD card. I’d wasted the entire shoot. What happened?  I still don’t really know. I’m using CHDK so my camera now has about 8 zillion tiny menu options, and eventually I just reset everything and re-enabled the USB remote feature.  Then it worked again.  It was so weird because during the entire shoot it was acting as if it were taking pictures.  Now I know to really watch the “remaining frames” number and make sure it’s actually going down.

Red Candle Disaster Waiting to UnfoldI did two more shots: a green one and a red one.   For the last shot, I  propped the camera rig up with some clothes pins on top of an empty cardboard box so I could have a shot looking down on the candles.

The Mystical Garden Poltergeist Wreaks Havoc

I sat with the camera until all the candles were out, and then I left.  When I came back, I found that the camera had flopped forward and done a face plant on the rocks!  In a panic, I tested the camera, but it seemed to be working.  While looking at the time lapse frames, I noticed that at the frame where everything went wrong the words “Mystical Garden” were eerily smeared across the rock.  Was the ghost of my previous time lapse jealously haunting the set?  No, but almost as miraculously, the camera shutter had been open during the exact moment of  collapse and had taken a smeary photo of the nearby box my crystal growing set had come in!



I hear by swear off the Cardboard Box and Clothes Pin Mounting System.  Time to build a tripod mount and lay this Mystical Garden to rest. You can see all the candle time lapses here.

Building an Arduino based Motorized Camera Rig

I’ve always wanted to make a time lapse video. It’s like building a machine to catapult forward in time.  What could be more fun?  I really feel like the best time lapse videos integrate camera motion to give the scene an additional compelling dimension. I spent a couple of evenings building a quick and dirty motorized camera slide from a dead inkjet printer. It was a failure.  It was unable to produce the slow steady motion needed for video, much less the kind of control needed for time lapse.  I started to think about what a serious system with substantial time investment would have.  It could be bigger and have at least two-axis camera motion.  It would need a bunch of software with some way of key-framing the camera motion, maybe an LCD display, maybe a pendant control for stepping/snapping frames without jiggling the camera.  What else?  A way to power and auto-trigger the camera for time lapse.  All in all a much, MUCH bigger project.  OK, if that’s the end goal, what’s a good first step? I’m always wary of  physically big projects. As the size goes up, costs go up. Big projects are harder to get into/out of the car, take up more workbench space, and ultimately collect dust in a bigger way.   If I can fit a project into a single project box, life is simpler.

Bigger Motor ControllerSo instead of embarking on a large two- or three-axis rig, I decided to build a very small one-axis rig.  Heck, I already had a small one-axis slide.  This way I could get my feet wet with the software, LCD, motor controllers, and all the other fun stuff, but without as much schlepping. A friend of mine pointed out that a little motorized stage like that could also be used for focus stacking, and he’d been wanting to build a focus stacking rig.   He sent me little linear slide with a stepper motor drive and a tiny ball screw.  I’d never seen a ball screw that small!   It was sweet!  I poked around on Amazon and ordered a A4988-based stepper motor driver the size of a postage stamp.  They were cheap, small, and the data sheet made them sound like they were doing a decent job with the microstepping, which might be useful for very precise focus stacking.  I used to build stepper motor drivers out of discrete components, but it’s unbelievable what you can get these days for not much money. I’ve been itching to try some of the pre-made ones out, so I ordered the stepper motor and a much bigger driver board based on the TB6560, mostly because I was having trouble convincing myself that a driver without a heat sink was really going to be able to do the job. And even the big one was cheap.  It was less than $17,  including two-day shipping to my door. I’d also been wanting to play with some of these cheap LCD displays I see around, so I ordered a 4-line 20-character blue one that Amazon Primed its way to my house for $16. I ordered the blue one because a green-and-black LCD was going to make the project look like it was from the early 90’s.  I ordered one that had an I2C daughter board because I wasn’t sure how many IO pins this project was going to need, and I didn’t really want to burn half of them driving the display. When the display came, I was bummed that they’d shipped me the green and black version, not the blue one!   I set my time machine for the early 90’s and kept moving.  I wired up the display to an Arduino Uno.  I downloaded the Arduino IDE and a library to drive the display.  I wired it up like this:

Screen Shot 2014-04-23 at 8.44.48 PM

Then I ran this exciting bit of code.

#include <Wire.h> 
#include <LiquidCrystal_I2C.h>

//Addr: 0x3F, 20 chars & 4 lines
LiquidCrystal_I2C lcd(0x3F,20,4);

void setup()
 lcd.setCursor(0, 0);
 lcd.print("Hello World");

void loop()

Two DisplaysThankfully, it just worked.  The text was super crisp and readable.

I was still a bit bummed about the color, so I decided to roll the dice and try ordering the blue display again.  I’d be able to compare the two colors side-by-side and see which one I liked best. This time I did get the blue one. It worked and was crisp and clear.  Our eyes don’t like focusing on dark blue things though, and if I had to be brutally honest I’d have to say that the green display was more readable.  I decided to switch to the blue one anyway.

Special CharactersI wrote a little program to page through all 256 characters that could be sent to the display to see what sorts of special characters might be available.  There were a few useful ones like left and right arrows, the deg symbol, and a solid block character which I might actually use in my interface.

The next step was to put the various parts I was thinking about using together to visualize how things were going to fit.

Component Layout And Sizing

I was originally going to mount everything to the side of the motorized stage so I could cut down on external wiring.  I could even put the end-of-travel sensors inside the project box.  But it was starting to look 10 pounds of project in a 5-lb bag.

The project box was big, and it was going to have to be right under the camera or using it would be uncomfortable and trying to manipulating it would jiggle the camera.  Those issues seemed like deal breakers.  The next plan was to put the control box at some distance from the motor and make a separate control pendant that could plug in.  I’d need OK and Cancel buttons and some sort of spring-loaded pot for jog control.

Remote Jog WheelI went poking around at the local surplus store and scored a VCR remote with a nice spring-loaded jog wheel.  It even had two buttons inside the wheel, so I thought my control pendant problems where over.  I’d wire up the jog wheel/buttons through a phone connector to the main control box, and I’d be all set.  However, when I dissected the remote, I found that the jog wheel was not a pot.  It had 3 digital pins providing gray code position info.  That meant only a few jog speeds in each direction, and it meant I’d need more lines than a standard phone cord.  Back to square one.

Spring Return PotI decided to take a stab at adding my own spring to a pot to make a “return to center” jog controller.  I drilled a hole through the pot’s shaft and bent up a spring.  It worked. After some fiddling, I was able to make it control the motion of the slide.  It had a really sloppy feel to it. The center was always just kind of approximate, and it was harder to turn in one direction than the other.  Kind of a cruddy experience compared to the feel of the remote’s nice jog wheel.  I decided to punt for a while and work on other parts of the project.

End of Travel SensorsI wired up the end-of-travel sensors.  I was using IR gap sensors for a no-contact way of measuring the travel.  Now that the sensors couldn’t be mounted inside the project box, I decided to make them fit inside a bit of metal wiremold that I had lying around.  I used some Bondo to hold the sensors at the correct height and support a phone jack at the end so the sensors could be easily connected up.

This was by far the most annoying part of the entire build.  The phone jacks turned out to be back-stabbing fiends.  Fitting everything in the wiremold was annoying, and I had a wire tear out when I was closing it up.  Then the sensors weren’t working, so I ripped everything apart trying to figure out why. I had accidentally grabbed a two-conductor phone cord even though I’d  purchased a 4-conductor one. Then when I finally figured that out, I failed to realize that when using phone connectors, the wires get flipped from left to right so red on one end becomes green on the other, and black becomes yellow.  *Smack Forehead*  After I figured that out, I thought I was home free, but it still didn’t work.  I finally traced the problem to a poorly designed jack where the connector could clip in, but was still not fully seated and wasn’t making contact.  After that got resolved, everything was fine. But I’d burned an entire afternoon trying to run 4 wires a few feet.

Quick Release Plate MountedI got a super cheap quick-release plate.  When I was taking it out of the packaging, a spring and pin fell right out of the bottom.  I deemed them to be unnecessary and threw them out.  Then I noticed that  the cam lock tends to slowly unscrew and the screw can’t actually be tightened properly without making the cam hard to turn.   A dab of Loctite could solve that.  Hey, it was cheap!  My only regret is that I wasn’t able to mount it so the cam stuck out the same side as the wiremold.  This would have made the whole thing more compact left to right, but that might have required tapping some blind holes, and this way around it was simple to mount.  Just a 1/4-20 though an already existing hole in the carriage.

LCD Rig Wire MessI had all this wired up to an Arduino Nano.  It could jog the motor when I twisted the pot, and it could read the end-of-travel sensors.  Next was to start designing some UI for the LCD.  I played around with being able to highlight various menu options by quickly toggling the solid block character behind them, etc.  It all seemed doable, but it was kind of tedious Arduino development. I kept thinking “How is this going to scale up for multi-axis key frame animation craziness?”

 Massive Feature Creep Occurs

It was then that I noticed Bluetooth LE boards for the Arduino.  Could I control my whole rig from an iPhone app? I could ditch the LCD, buttons, pendants, and all the associated wires and connectors.  I could make the project box smaller.  I could write an iPhone app to do the interface heavy lifting, and I’d only have to do a moderate amount of stuff on the Arduino end of things.  No more planning out of awkward LCD interfaces.  Plus, it just sounded fun!

Blue Tooth ConnectedSo I ordered one of the boards, and I was off to the races. Adafruit’s page about wiring up the board is very clear, and I hooked up an Arduino UNO just to try it out.  I was able to get their UART echo communication going right away.  Simple, Pimple.

The next test would be to write my own program to establish the Bluetooth communications and see if I could use a slider to jog the motor.  I wanted to test the latency and to see if stepper motor switching noise would affect the communications.

The great thing about Bluetooth LE is that you don’t need any special licensing.  I spent one of my precious Wednesday nights ripping the com parts out of the Adafruit example and sticking them into my own simple app.  The app just had a connect/disconnect button, a connection status indicator, and two end-of-travel indicators. The communication is only 9600 baud, so I made a special jog loop the Arduino could go into where the phone would keep sending single bytes of  jog slider info, and a 0 would indicate that the jog portion was done and go back to the main loop.

The very first version wasn’t wired to anything. It would just indicate end-of-travel limits having been reached if you slid the slider close to the end of its travel path.  After tracking down an issue with a rough signed char, I got it working. The latency was quite low.

Jog Actually WorkingNext up: rewire the Nano to remove the LCD/knob and wire in the Bluetooth LE board.  Then I’d be able to jog an actual motor. I powered it up and could hear the motor making some ticking sounds, but jogging wasn’t working.  I went to hook up the scope and bumped the alligator clip that was providing motor power.  It touched something on the board, and the Arduino’s LED’s went out.  Yup, I’d fried the Nano.  Ouch. Oh dear. Had I fried the USB port on my computer?  Apparently not. *phew* No need to panic.   I did not, however, have a spare Nano on hand.  Trying out the jogging was going to have to wait until next week.

Jog On OscilloscopeIn the mean time, I rewired some parts of the protoboard to make it a bit less hairy.  I don’t want accidental short circuits killing things, but I also don’t like clipping the leads on resistors and caps.  When the replacement Nano came, I decided to only connect motor power after I was reasonably sure the other things were working.  I  used the oscilloscope to see if the Nano was producing the expected step pulse trains.

Yup, that seemed to be working.  With some trepidation, I decided to try and hook up motor power again.   Nothing burned out, and it worked!  Next I needed to see if the limit switches worked. I jogged the stage all the way down to the end, and one of my limit indicators on the iPhone started flickering like crazy. But it was the wrong indicator. I swapped near/far sensors and added some software switch debouncing.  The slow linear ramp of the limit sensor was producing a lot of noise when it got close to the logic level boundary.  I’d love to run it into a nice Schmitt Triggered gate.  That would keep the software nice and clean, but if I was going to have PCBs made, it would add area and expense.

I could have made them go-to-analog inputs and just used two thresholds.  That’s probably what I should have done, but  stepping at 1/16 of a step was putting me at 54400 steps per inch, which was really taxing the powers of the accellStepper library and I didn’t want to add much to my inner loop.  That’s probably silly of me and adding two analog reads to my loop wouldn’t matter. Instead, I did digital reads and required a large number of matching consecutive answers before alerting the iPhone. Probably over complicating the code since the real bottleneck in accellStepper is probably its use of millis() not a couple of  analog reads.
Camera On RigNext up was to install CHDK on my camera and see if I could manage to use a USB cable to act as a remote shutter switch.  CHDK runs on various Canon cameras and lets them do things they normally couldn’t.  My camera (a Canon S100) didn’t have a way of remote triggering, so I had to hack it with CHDK  to do that.  You have to make a special bootable SD card.  I used a tool called STICK to analyze a photo taken by my camera, determine the exact firmware in the camera, and download and format a bootable SD card.   This made setting it up simple.  Then I went through a maze of  menus to turn on remote shuttering. I wired one of the Nano’s output pins to my camera’s USB port and wrote a snippet of code to take a picture. It worked! Right now I hold a line high for 1 second, and then it takes a photo when the line goes low. I haven’t tried running a shorter cycle.  Maybe with manual focus/metering it could take photos more quickly.  I haven’t tried.


I had motion, I had photo taking. It was time to try and do a time lapse with this rig. I took it over to my son’s Lego studio area and set up a magic crystal garden I’d purchased online.  I used fun-tack and clothespins to aim the rig, plunked an old calendar photo of clouds in the background, and we were almost ready to go.  I set all the camera settings to manual. Then I set the code to move though the system’s full range of motion over 10 hours, taking one frame every 2 minutes for a total film length of 10 seconds.

I waited until it was dark, and I fired off the time lapse.  It felt like Christmas Eve,  and I didn’t know if Santa was going to leave me a time-travel movie or a lump of coal. I told the kids we couldn’t go into the garage for 10 hours. In the morning, I went out to see what had happened.   The first thing I noticed was that one of the big chunks of foam I’d taped up over the garage windows had fallen down during the night.   Oh, oh.  Still, the crystals were fully grown and there were 300 photos on the camera, so it was time to try and play them as a movie.   Unfortunately, iMovie only lets you specify still frames down to 0.1 seconds in length, so you can’t really make a 1/30 of a second one-frame-per-image movie.  Argh!  Photoshop can do it, but that requires loading all the frames into layers. On my machine, loading in 300 big 3000×4000 pixel images was taking for-ev-er.   Finally, I just downloaded some freeware frame encoding tool and used that to build my time lapse.  Then I could use iMovie to add title, fiddle with the sound, etc.  By 11am, I’d finally managed to unwrap My First Time Lapse.  It was over-exposed and didn’t have great focus, but the kids thought it was cool.  Success!