OK, you've assembled the pan/tilt mechanism and it looks cool, but it would look even cooler if it actually moved. One nice thing is that you don't need a battery to move the pan/tilt -- the pan/tilt can use the USB cable for power, but you must use a 4 ft or shorter cable. (3 ft is common, and even better.) If you use a longer cable, there can be up to 1 volt of voltage drop along the cable, which is fine for Pixy, but the servos will malfunction. Also, before you run the pan/tilt demo, go ahead and teach Pixy an object.
There are two ways to run the pan/tilt demo.
Running the demo with the button
When Pixy first powers up, you'll notice that the LED turns on (white) for about 1 second, then flashes, then turns off. What's really happening is Pixy is asking you which program you want to run. Currently, Pixy ships with two programs:
the default tracking program that detects objects and streams them out the port you choose
the pan/tilt demo
So, power up Pixy, and when the LED turns on (white), hold down the button. The LED will turn red then orange, red then orange, etc. If you release the button when the LED is red, you will select the default tracking program. If you release the button when the LED is orange you will select the pan/tilt demo. So do that -- release the button when the LED is orange. The LED will flash orange a couple times which means "running program 2!"
And then Pixy should track your object. Yay!
A quick note on program selection -- normally, upon power up, if you don't press the button, Pixy "times-out" and just runs the default program, which is the tracking program, but you can configure which program is the default program from the PixyMon Configure Dialog.
Running the demo from PixyMon
If you're running PixyMon, you can run the demo (or any other program) at any time by selecting it in the Action menu. In particular, select Action➜Run the pan/tilt demo.
Pixy should then track your object and print the position to the command window. Yay!