Building a timelapse slider rail with Arduino - Part 1

Hey guys

I thought it might be interesting to show you a project that I have been working on; a timelapse slider. If you havent seen one before, it allows you to take time-lapse videos and move the camera at the same time. You end up with footage that looks like this.

This video was taken with a finished prototype of the slider earlier this year. However, I tried to get a final version created but I couldn't get it to work and sort of gave up. However, I've decided to come back to it and this time get a proper printed circuit board made up from my plans.

So i'll start with the hardware of the slider.

What I have here is a Drylin CNC rail and carriage system. I have a couple of rails, a 2ft and a 3ft one. I fabricated the parts that attach to the end; the one in this picture would have a stepper motor attached to it. The motor then slowly turns the threaded bar which in turn moves the carriage along the slider very slowly. Camera is mounted on top of the the carriage using a standard tripod ball head. This is the only thing that I'd like to do better - I might get someone to fabricate a better way to mount the ball head as the MDF bracket looks a bit crap.The whole rail is mounted on a normal tripod.

Here is a short video of the rig in action

So i'll quickly run through the components in this post and in future posts, go through the electronics side and Arduino programming in more detail.

So this is a "non-wired" layout of the main components that im using - there are a lot of resistors/capacitors etc that arent shown on this breadboard.

Starting top left, you have a 16x2 LCD display, 4 buttons, bit-shift chip and a small potentiometer. The components together allow you to display text on the LCD and navigate around a menu system using the 4 buttons. The potentiometer allows you to change the brightness of the LCD. I have a full software library that allows me to create a menu system and navigate around it, saving settings to the Arduino's EEPROM. Will go through that and how to use the bit shift register to display text on the LCD screen in more detail in another post.

Below that, you have the stepper motor on the left, stepper motor driver chip and some screw connectors that are for the stepper motor cables. Simply put, the stepper motor is two coils that take 12v each and the signal to these coils is alternated to move the stepper motor in distinct steps (200 steps per revolution). This is really fine-grained control which is what you need for the precise movement of the camera along the rail. The stepper motor driver chip is a pretty simple bit of kit. It allows you to use the Arduino to decide how much to move the motor, and how quickly to do so. I'll go through that in the next post.

The final small component on the right is an optocoupler. This is used to trigger the camera shutter. I chopped the end off a remote shutter release cable and use the optocoupler to short the connections on that to fire the camera. You have to do this as there is no way to use the Arduino to simply short out two contacts without providing an electrical current. I'll go through how that works in more detail soon.

If you are interested in seeing this being created and hopefully a fully working bit of kit at the end, follow me and let me know in the comments below.

Thanks for looking

Mark