I had Brandy send me an example of her program to clarify the problem.
 
The program used a loop to repeatedly test the touch sensor and either go forward or back up and turn.  She could have used a logic value to exit the loop but really the approach wasn’t the best to begin with.
 
A better solution would be to tell the motors to go forward “forever”, use a WAIT block to wait for the touch sensor to be pressed, back up and turn.  This sequence can be repeated as many times as needed.
 
Of course a better programming approach would be to avoid duplicate code and create a My Block for the “go forward forever, wait for the touch sensor, back up” part.  Then the main program would be MB, turn right, MB, turn left, MB turn right.  Alternatively, the MB could do the turn itself using an input logic value to determine which direction to turn.  Then the main program would be MB, MB, MB.
 
I sent her examples of these solutions directly.
 
Thank you Brandy, for asking a good question!
 
 
Stuart Roll
River Bend Robotics Coach
 
From: [log in to unmask] href="mailto:[log in to unmask]">Brandy bergenstock
Sent: Monday, July 04, 2011 11:46 AM
To: [log in to unmask] href="mailto:[log in to unmask]">[log in to unmask]
Subject: [VADCFLL-L] Programming query- how to count inside of a sensor loop?
 
I created a maze for my students and let them go at it.  One student choose to use a touch sensor, which was a good idea.  Now the maze had the robot traveling 1 right turn, two left turns, and then a right to finish the maze. ( On average this maze took 1.5 hours to program for each group.)  The student ended up using a timer on the loop, allotting the loops enough time to run until they finished their task and moving on to the next loop.   Not bad for a brand new programmer :)
  But surely, there has to be a away to make the loops count themselves. How would you tell the robot, after each touch, count it, then stop after you reach "x" touches? 
I am really trying to wrap my head around the wires.  I know there is a logic and a math block that would possible to use for this idea, but that I can't seem to figure out how to wire it up.
    Any help to this end would be greatly appreciated!
(Also to the coach and his son that was considering an advanced robotic programming class on-line , I'm still eagerly awaiting that news on that seminar set :)
Regards,
Brandy

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