12. Changing the Inventor Level

Taking More Control

When we practiced turning the Cart we turned a motor off for a period of time. But there are problems with this.

1. The motor could only be stopped for either 1, 2, 4, 6, 8 or 10 seconds. What if you only wanted half a second, or, say, 5 seconds?
2. The RCX only operated at a single power level.  Sometimes, the RCX needs to speed up and sometimes, especially when turning, it needs to slow down.

  Changing the Level

1. Start RoboLab.
2. Choose Run Robolab.
3. Select Programmer Option.
4. Choose Inventor 2

More About Level 2

• Level 2 gives more control over choosing sensors, motors, lamps etc and more control in setting options such as power levels and wait times.
• This is achieved through the use of modifiers. These can be seen in the sample "dummy" program loaded when Robolab Level 2 is started up.

• While the icons do not show which ports are being used, the modifiers reveal that the Motor on port A is activated together with the Lamp on port B and the Touch Sensors on 2
• The other modifiers display the power levels.  Both the motor and the lamp are turned on to power level 5 - full power.

Seeing the Differences

Watch the differences! Go Full Screen to see in greater detail?

The Movie shows two programs.

1. The original program of an RCX Cart turning for one second at full power.
2. It then shows a further program where the RCX moves at half power and turns for only half a second.

Notice the difference in the two programs. The movie below demonstrates the second program you saw with additional modifiers used.

Using Modifiers

In the movie you can see:-

1. Motors A and C are turned on at power level 3 (half power).
2. The motors turn for 1.5 sec's before A is turned off, causing the RCX to turn.
3. Motor A restarts at half power for 2 seconds before the motors stop and the program ends.

Building the program with Copy and Paste! Go Full Screen to see in greater detail?

What you have to do!

1. Start the Robolab Software - if it isn't already open.
2. Make sure you choose Inventor Level 2.
3. Create the program shown in the movie and transfer it to the cart.
4. Once the program is working correctly Tick Off Task 12 in the main Robolab Progress Grids.

Continue to Round the Houses Challenge - Exercise 13: