Follow Focus Sketch (WIP)
In this post, I am going to detail a few of the specs of my DIY wireless follow focus.
The basic setup of the whole DIY system is this:
>A camera is mounted on
> a platform (in my case plywood) which has attached to it
> a 2 axis arm with the servo which is attached to
> a project box housing which contains
> the Arduino receiver setup
>A project box contains
> an optical encoder connected to
> the Arduino sender setup
Each arduino setup is comprised of:
1 Arduino UNO board
1 Sparkfun Xbee shield
1 Xbee wireless chip
1 9v battery connected to the Arduino
My camera focus gear is a Jag35 focus gear which can be found here if you don’t already have a gear:
The servo is a 12 dollar mini servo I picked up from a local hobby store and the gear on the servo is a 72 tooth 32 pitch gear I purchased online (can’t remember where but there are plenty of places that sell hobby gears).
And last but not least, the code:
The sender code is not perfect, but I think I have worked out all the bugs. However, when I was first learning how to read optical encoders, I went on to also learn how to use interrupts if I would ever need to use them. I ended up forgetting to take the interrupts out because they never caused me any problems but they are not needed in there. They also cause the Arduino to skip a degree when you move the encoder at a fast rate. If you simply remove the interrupt and redo the code to just read the encoder and send the +1 or -1 step, it works fine. I just haven’t gotten around to doing that yet because this is my final semester in college and finals are next week.
Also, if you make any improvements to the design/code/setup/anything else, I’d love to hear about it! Just send me an e-mail so I can update my design and post progress here.
I am a big proponent of FREE DIY resources and information, so have fun and build away! However, any donation, no matter how small, will be much appreciated and every cent will go toward funding future films and DIY projects!