motion control of robot

how 2 control a robot thru joy stick? plz help

most joysticks are two-axis joysticks. they have two potentiometers inside them, which rotate when you move the stick of the joystick. this potentiometer is connected to a 5 v Vcc, hence when you move the stick, you get two analogue voltages on the two potentiometers, proportional to the position of the joystick. i.e.. it is mostly 2.5 v at neutral position, and decreases or increases as you move it toward the extremes. these voltages can be analysed through ADC, to give a digital form of the position of the stick. this can then be used in the code of your micro controller.

another easier way is to imply fee these signals to comparators, with suitable thresholds, and take logical outputs. this however kill the whole purpose of the joystick.