Grade 8 STEM teacher. Robot C with Mindstorms - main focus of class.

A student typed this code:

task main()
{

motor[motorC] =100;
motor[motorB] =100;
wait1Msec(4000);

motor[motorC] = 100;
motor[motorB] = 0;
wait1Msec(850);

}

Robot only move straight with no turn(which is what they want). If I remove the turning code(2nd set of three lines) the robot behaves as it should (go straight for 4 seconds). Once I put the code back in line it runs for approximately 6 seconds. No idea what the issue is. Please help.

Thank you very much.

Josh

What happens when you replace the 850 millisecond wait with a longer period of time (say, 2000 milliseconds)? Does the robot turn correctly then? The only thing I can think of is that the wait command is not long enough for motor C to 'push through' the additional friction of motor B being stopped. On that note, I tried the code you have posted on an NXT bot with a fresh battery (REMBot) and it worked correctly; double check the battery level of the NXT to see if it is low, and if so, I would suggest charging it fully and re-testing the code.