How to achieve continuous rotation on a bipolar stepper motor.

Using Arduino Programming Questions
3 
const int ForwardLimitSwitchPin = 2;
const int ReverseLimitSwitchPin = 3;
const int StepperStepPin = 4;
const int StepperDirectionPin = 5;
const int LimitSwitchActivated = LOW;  // Limit switch grounds pin
const int StepperMaxRPM = 100;

Stepper stepper(200, StepperStepPin, StepperDirectionPin);

void setup() {
    pinMode(ForwardLimitSwitchPin, INPUT_PULLUP);
    pinMode(ReverseLimitSwitchPin, INPUT_PULLUP);
    stepper.setSpeed(StepperMaxRPM);
}

void loop() {
    // Step forward until the limit switch is activated
    while (digitalRead(ForwardLimitSwitchPin) != LimitSwitchActivated) {
        stepper.step(1);
    }
    // Step reverse until the limit switch is activated
    while (digitalRead(ReverseLimitSwitchPin) != LimitSwitchActivated) {
        stepper.step(-1);
    }
}