Скачать или смотреть Pan and Tilt smooth control using an Arduino and DC motors, p1 Tutorial.

When using high magnification scopes on top of a PTZ base smooth speed control is critical, this little project implements speed control on a PT base using DC motors and Arduino.

Components: Arduino board, L298n Motor driver board and two axis Joystick module.

In any real PTZ base there are always stop switches that limit the base range of movement, two pan limit switches and two tilt limit switches, when using DC motors these limit switches have to be connected in series to the corresponding DC motor, for example the two pan limit switches will be connected in series to the pan DC motor and the two tilt limit switches will be connected in series to the tilt DC motor. The only detail to take in count here is that when one limit is reached the circuit will open and no current will flow in any direction, to fix that a diode have to be placed across each switch to allow current to flow in the opposite direction.

Extra details and full source code in this link:
https://drive.google.com/folder/d/0Bx...

For this to work you don't need necessarily an Arduino board or do any programming, there is an alternative way by using a Pulse Width Modulation PWM DC Motor Speed Control Switch(http://www.ebay.com/itm/121215526161)and DC motors, using two of these switches, one for each DC motor you can do exactly the same thing without the use of any micro-controller.