Jun 19, 2011
An update to my track view camera project.
Camera Sync
An important part of the system is having all the cameras taking photos at exactly the same time. The GoPro HD cameras have a "Hero Bus" connector in the back, this is used to connect accessories like extra battery, LCD screen, and crucially a 3D Sync cable.
After a bit of track tracing and prodding with a multimeter I had the sync cable reverse engineered. And then not long afterwards, the "protocol" for controlling the slave camera
So now I can trigger all cameras within 1/60 of a second which is close enough for me.
Housing
I want to create a housing than anyone can reproduce for themselves without any prohibitively expensive manufacturing process. I started off mocking up a housing with 3mm and 5mm Foam Board. A photo was snapped of this at the Tangleball Open Day. The foam board was great to work with and quick to iterate through designs. Initially I had the cameras angled down at 20 degrees, this turned out to be too much so a few quick cuts and some more superglue and I had the cameras angled at 15 degress which worked much
A couple of days later and Ponoko had cut it out and sent to my way. Quite some days later NZ Post finally decided to deliver it to me.
After about an hour and a half unpacking and removing the backing of the pieces and assembly I had my first prototype built in plywood. I as impressed with the accuracy of the cuts, I had 3mm holes for bolts in my design and the were perfectly cut out. It all when together surprisingly easy, although I had made a few mistakes.
I had a couple of places where two parts wanted to occupy the same space and a couple of angles wrong. One resulted in not all the bolts being installed and once results in some "corrections" being made with a Xacto knife.
Another photo here.
Prototype 2 is already with Ponoko to be cut. This one has a bit more care put into it and addresses issues with the first prototype. It adds a mount for the top camera, holes in the base to access the SD cards, shrinks the overall diameter by 16mm and the height by about 8-10mm.
Software
I took a few test photos with the foam board mockup. Below is a test panorama in Google Maps. This is before I angled the cameras up further, if you "look down" you'll see me.
Mounting on pack
I have created a frame out of simple plumbing parts to allow the camera to sit directly above my head while wearing my hiking pack.
The second prototype being cut by Ponoko at the moment has pieces to mate the camera housing to the PVC pipe on my pack.
I'll update this post tomorrow with photos of this.