This contraption is certainly my most interesting so far. Since the camera
itself provides no method of mounting, it was hard to create a simple
adaption to allow for rotation. This is my adventure.
A quick summary: The camera is contained in a self made brace which is
superglued to the shaft of a stepper motor which is connected to a circut
of 4 transistors which are controlled by the parallel port.
I modified the server program I use for the lamp and it now controls both
the lamp and the stepper motor. The lamp required one data line, the motor
required 4. Since the motor can be operating while the lamp is on, and
since both devices are controlled by the same parallel port, it now became
necessary to have a "state" variable which keeps track of which data lines
on the parallel port are currently active, so the lamp doesn't get shut off
during a motor routine.
Each of the 4 transistors for the motor is triggered by one of the data lines
from the parallel port. Each transistor then controls power to one of the 4
stepper motor contacts. Each contact must be given power in sequence to make
the motor turn in one direction or another. So, in addition to remembering
what the parallel port currently looks like, its also important to remember
which contact was touched last. The server controls all of this to make the
circutry as simple as possible.
The power driving the motor is a simple 9V DC power source, provided by an
AC 9V battery adapter.
The motor is built into a radio shack project box, to give it the required
support. The motor was obtained from a dead floppy drive. Floppy drives
are wonderful sources of stepper motors and I'm willing to bet you can obtain
them for free if you look hard enough. The end of the shaft has a gear
well attached, so I decided to simply glue this gear onto the brace I built
rather than trying to get the gear off by force (which won't be happening
anytime soon).
The brace is a very high tech contraption I built from my old erector set.
It simply holds the camera and keeps it from twisting around too much. I still
have a problem with the cable leading from the camera, as it tends to pull on the camera if the motor turns it too far. I therefore set a maximum rotation
angle to 90 degrees. This is adaquate to view most of the room and everyone
in it.
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