14. Using Light Sensors

Earlier it was shown that the RCX Cart can react to it surroundings using a Touch Sensor. The Cart can also react to changes in the amount of light it "sees".

Different icons can be used with the light sensor.

This icon means, “wait until the light sensor reading is darker”.

This icon means, “wait until the light sensor reading is lighter”.

Light Sensors In Action

See it STOP when it gets lighter! Go Full Screen to see in greater detail?

1. The movie shows an RCX moving towards an obstacle.  The display shows that the RCX shows an initial reading of  45. - dark surfaces reflect less light.
2. The program is created so that the RCX will stop when the light reading increases by 5. When the RCX is over the paper the light reading is 51. So, the RCX stops. - light surfaces reflect more light.

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 to make the Cart work like the one in the Video.
4. Transfer your program to the cart.
5. Once the program is working correctly Tick Off Task 14 in the main Robolab Progress Grids.

Continue to Exercise 15: