How can I stop my Servo rotating?

Question

I have a continuous servo motor connected to my Arduino UNO. I want it to react to the Hexadecimal code received by an Infrared remote. I want the motor to rotate once in one direction and then rotate once in the reverse direction and then stop until triggered by the remote again. At the moment, the remote will cause the the motor to rotate once in one way but then it rotates continuously in the reverse direction. Any help would be much appreciated!

#include "IRremote.h"
#include <Servo.h>

int receiver = 11; // Signal Pin of IR receiver to Arduino Digital Pin 11

Servo servoMain;
IRrecv irrecv(receiver);
decode_results results;

void setup()
{
  Serial.begin(9600);
  Serial.println("IR Receiver Button Decode");
  irrecv.enableIRIn(); // Start the receiver
  servoMain.attach(10);
}


void loop()
{
  if (irrecv.decode(&results)) // have we received an IR signal?

  {
    translateIR();
    irrecv.resume(); // receive the next value
  }
}

void translateIR() // takes action based on IR code received

// describing Remote IR codes
{

  switch (results.value)

  {

    case 551520375: servoMain.write(180); delay(1000); servoMain.write(0);     delay(1000); break;
    default: break;

  }

  delay(500); // Do not get immediate repeat


} //END translateIR

Answer 1

Unlike a normal servo motor where the argument of the Arduino's servo.write(angle) method represents a position, a continuous servo motor uses the argument for speed and direction. Most continuous servo motors interpret stop to be approximately 90 degrees. Full, say, reverse as 0 degrees. And full, say, forward as 180 degrees. As stated in the above link:

On a continuous rotation servo, this will set the speed of the servo (with 0 being full-speed in one direction, 180 being full speed in the other, and a value near 90 being no movement).

Also of interest, most continuous servo motors have an adjustment to set the "90 degree position" (full stop). That is to say, servo motor control signals are analog, not digital! It follows that the processor's interpretation of the "90 degree position" may not be the same as the servos' interpretation of the "90 degree position". Hence the ability to adjust the servos' interpretation.

This picture from the parallax servo tutorials web site shows how this is done: