Saturday, July 14, 2012

PT785-S Pan and Tilt System + Arduino

I bought one of these a little while ago and finally got around to testing it with an arduino. This system isn't accurate enough for real-time repeatable motion control photography IMO. I'm planning on using it for capuring sphereical longitude/latitude HDRI's.

You can find the product here:
servocity.com/html/pt785-s_pan___tilt_system.html

9 comments:

JacksPixels said...

Damned !!!! It work great but it seem to be noisy ! Even if sound capture is not made on the pan/tilt head ... at what distance can we heard the servo motors ???

I'm planning to build a timelapse / video slider based on the heads and Arduino. Nice to see your demo.
Nice blog ... I discover a lot of thing I like :) Nice work.

JB
www.jacks-pixels.com

JacksPixels said...

Oh what about repeatable motion with this head ?
Any information ?

Dan Thompson said...

Hey Jack,

Yeah they are quite noisy. I haven't tested things out in the field. But it seems to land in the exact same spot every time as you would expect any pwm servo to do. However, this servo seems a bit different because it can do 2 or 3 rotations. It seems to have a built in ease out function. So, it slows down smoothly as it comes to it's programmed position.

So I'm not sure if the ease out function is repeatable. I would only trust this setup for and automated 360 pano rig.

Unfortunately if you want precision repeatability with torque to boot, you will have to pay for it.

It might be ok for timelapse if you balance it so the servos don't need to draw current when the camera is at rest (to save on battery) But I'm not sure.

Best,

Dan.

Thanh Dang said...

Hi Dan,

I'm planning to buy the PT785-S Pan and Tilt System. What else do I need to get to use it with Arduino?
I'm very new to this. But I need it the system to be able to take panorama picture by itself.

Dan Thompson said...

Hi Thanh,

you will need something to trigger the camera's shutter.

Here's a post I did on the subject.
http://danthompsonsblog.blogspot.com.au/2010/10/my-first-timelapse.html

From that point it's up to you how elaborate you want your interface to be.

I plan on having all the moves hardcoded and just a start/stop (hold reset) button to operate the whole thing.

here's a push button tutorial that might help you also.

http://danthompsonsblog.blogspot.com.au/2011/12/arduino-push-button-onoff-example.html

Good luck!

Anonymous said...

I suggest you chuck the servos and replace with stepper motors if you actually want repeatable and smooth control...

Dan Thompson said...

Hi Anonymous, For me this head was never intended to be used for repeatable motion. I will only be using it for automated HDRI panoramic capture. For gathering on-set lighting data for CGI reference. But yes agreed. The servos are no where near accurate and responsive enough for repeatable real-time motion control recording.

Lars said...

Hello there!
Interesting project. I have just gotten that very same head, but with plans of using it for closeups of wildlife - perhaps later on a mobile platform (aka robot). I have done some panos before and have toyed with the idea of using Arduino to control the head automatically. I will be following your blog with great interest.

Anonymous said...

Hey Dan,

Is there any tutorial you used or any pointers or guides you could direct me to for how to do this exact same thing myself?

Thanks!