robotc中getMotorRPM函数不会用

双木觅林

我按帮助文档里给的例子做，getMotorRPM函数得到的值也不对。
task main()
{

int speed = 0;

//Infinite loop
while(true)
{
   //If the motor is less than its target (100)
   if(getMotorRPM(motorA) < 100)   
    {
      //Increase the value of speed
       
    speed = speed + 1;
    displayTextLine(2, "%d", speed);



      //Brief sleep period (2 milliseconds)
      sleep(2);

    }

        //Then apply the value of speed to the motors
        //This should cause the speed to 'ramp' up
       setMotorSpeed(motorA, speed);
       setMotorSpeed(motorB, speed);
}

}

代码如上，显示的speed值一直都是120多，不管getMotorRPM(motorA) < 100的100改为多少，speed得到的值都是120多。怎么回事？

双木觅林

task main()
{

int speed = 0;

//Infinite loop
while(true)
{
   //If the motor is less than its target (100)
   if(getMotorRPM(motorA) < 50)
    {
      //Increase the value of speed

    speed = speed + 1;
    displayTextLine(2, "%d", speed);
    displayTextLine(4, "%d", getMotorRPM(motorA));



      //Brief sleep period (2 milliseconds)
      sleep(1000);

    }

        //Then apply the value of speed to the motors
        //This should cause the speed to 'ramp' up
       setMotorSpeed(motorA, speed);
       setMotorSpeed(motorB, speed);
}

}
得到的getMotorRPM(motorA)值达不到49，偏差3