What we are doing?
We need to provide an easy, steady way to do podcasts, pictures and other video bits around a project. What we want is a way of positioning a camera in 3D space from above. The ability to move it around in a controlled manner would also be useful.
How to do it
The best/easiest method is to suspend the camera from wires. By extending and retracting the wires in a controlled manner, we can position a platform anywhere within the bounds of the wires.
The minimum number of wires needed for this is 3. 4 however works better for a square room.
Originally, there was talk of using CAN-bus for controlling the corner motors. This however works out quite fiddly and expensive.
Bluetooth modules can now be picked up for less than $5 inc shipping. This provides a simple, reliable way of talking to the units. It also reduces the wiring requirements to power only. This could be provided via either a 12V ring, or 240V adapters, based on the exact mounting.
The controllers themselves will consist of a Bluetooth receiver, a micro controller (ATTiny2313), an H-bridge stepper driver and the associated regulators etc.
There will also be some GPIO pins broken out, to allow for other projects to use the same base board.
Each corner unit will have a controller and a stepper motor. The stepper is linked to a reel of fishing line. This provides a cheap, strong and light wire to work with. The wires all link to the central platform, mounting the camera.
The main controller for the whole setup will be a Raspberry Pi board, mounted on the central platform. This will talk via bluetooth to each corner unit, as well as a Wii controller for position control. It will also provide a wifi link for the camera back to the main computer.
What we need
Stepper Motors | $8.99 for 5
Bluetooth Modules $49 for 10