SkyShield autoKAP controller

ChrisFastie

A couple of folks involved with Public Lab have been working on a simple autoKAP controller based on the Arduino Nano. We now have a device that works great and we are ready to find out whether it might be useful to others. We designed a custom PCB which is a shield for the Nano and allows easy connection of up to four servos and two cameras. The circuit design is open source and freely available.

Our emphasis has been on operating Canon PowerShots running CHDK, so the current sketch just sends a 5v pulse that CHDK can detect to trigger the shutter. The "SkyShield" controller leverages the programmability of the Arduino, so the sketch can be easily modified to trigger other types of cameras or drive the servos differently.

I also designed a pan/tilt KAP rig for testing the SkyShield. This is the Saturn V Rig, a small 3D printed rig scaled for PowerShots. This design is also open source and is freely available on Thingiverse. I have had some success flying the rig in Vermont and Alaska this summer and produced some almost spherical aerial panoramas: http://publiclab.org/tag/half-spherical.



Details about the rig and controller are at the following links.
SkyShield circuit design (open in Eagle CAD):
http://kaptery.com/files/documents/skyshieldv2.4.brd
SkyShield user manual:
http://kaptery.com/files/documents/skyshield-manual.pdf
Saturn V Rig 3D printing files:
http://www.thingiverse.com/thing:845522
More details (assembly instructions, Arduino sketch, parts list):
http://kaptery.com/guides/
Flickr album:
https://www.flickr.com/gp/chrisfastie/LEb736

I have stockpiled all the parts needed to assemble several SkyShields and Saturn V Rigs and have kits and some assembled units available at the KAPtery http://kaptery.com/products/?f=category&id=21.

This is the public release of the SkyShield and Saturn V Rig. Our goal is to offer inexpensive kits for building simple but useful tools for aerial photography. We are still developing both designs and are eager to hear suggestions for modifications.

Thanks,
Chris

YvonH

Cool design. :-)
How much does it weight without the camera?

ChrisFastie

Oh, thanks YvonH. I keep forgetting to include that. As configured in the video (batteries, cables, legs, Picavet, etc.) without the camera the rig weighs 339 grams (12 ounces). Now I have to go add that at several places.

Chris

mathewL

I still have to process and sort the images I took this past weekend on my Saturn V's maiden flight, but I'm very pleased!

ChrisFastie

The fall colors in Vermont have inspired me to put the Saturn V autoKAP rig into the air (first time since July, yikes). I also got carried away projecting the half-spherical panoramas as "little planets" using Microsoft ICE's stereographic projection. A few examples are below, and more details about three different flights are at Public Lab: http://publiclab.org/tag/littleplanet.

Chris

ChrisFastie

In the last week I added three more half-spherical panoramas to the little planet link at Public Lab: http://publiclab.org/tag/littleplanet. The Canon S100 has been recording GPS data for each photo so I was able to illustrate the rapid descent when the camera survived a hard landing:

Above: Being there was even more exciting than this graph. In the last 40 seconds, the camera descended almost two feet per second. More here: http://publiclab.org/notes/cfastie/10-25-2015/uncontrolled-reentry


Above: Vergennes, Vermont, stitched from 23 photos. More here: http://publiclab.org/notes/cfastie/10-25-2015/cloudy-bright

Chris

YvonH

Interesting stuff. Thanks for sharing.
What caused the camera to come down that quick?

ChrisFastie

Directly upwind of me was a 500 foot tall hill. When I pulled the kite in far enough it must have entered an eddy whipping around the hill. The kite was actually blown back towards me. I was very lucky not to have done more damage.

wayback

I somehow missed the original post. Chris, this is very cool. But I'm having trouble locating the schematic drawing for the shield. Can you help with that?

Also, I just told you everything I know about controlling servos. Can you recommend a source for learning about that? I assume it's some kind of pulse-modulated output from the Nano.

Well I guess next you'll be adding radio contol, so it won't be "auto" anymore. :-)

ChrisFastie

The Eagle Cad file for the SkyShield can be downloaded at this page: http://kaptery.com/guides/ (near the bottom, right click and save file). That file has the schematic and the graphical rendering of the PCB if you can open it in Eagle. The schematic looks like the one below (although the headers [JP1,2,3] don't seem to be assigned to the correct pins here, don't know why at the moment).



The traces are all correct in this rendering (this is the version I have been flying):


Arduino has really good tutorials and other resources for running servos. Here are a few examples:
https://www.arduino.cc/en/Reference/Servo
http://playground.arduino.cc/Learning/SingleServoExample
https://www.arduino.cc/en/Reference/ServoWrite

It's quite fun to write sketches and see what they do to your servos. So far it's been empowering to have complete programmatic control over when the camera shoots and where it is pointed. I don't have any plans to add radio control. It would be nice to add better power management so smaller or fewer batteries were needed. Anybody know how to add a boost converter to this circuit? It should be possible to use only three or four AAA batteries and supply 6 volts for a long time. Although with the circuit in the version above six AAA seem to last for a few hours, so it's quite functional. In fact it's been a real joy to get a half-spherical panorama with almost every flight.

Chris

wayback

Thanks for the info. I tried to download Eagle but it balked for some reason. I'll try again tomorrow.

Wind Watcher

Chris,

Impressive bit of work on the KAP rig and arduino controller!

Like it.

Like the flexibility to change the number of images taken in each position to avoid excessive duplication (like the straight down shots).

Job well done.

WW