Robot Challenge

When you want to draw a number of things on the NXT display, you use more than one Display block, as shown at right.

Each one has settings (computer folks often call these "parameters") that determine what is drawn on the display. These are shown at the bottom-left of the NXT programming application. You can draw images (pictures), text, or drawing, such as lines and circles.

So you strings a number of Display blocks together to make something interesting or useful on the NXT display, download it, and run it. Only the last of your Display blocks worked!

What happened? One of the parameters is a check box labeled "Clear". If this is checked, then the display is cleared before that drawing operation is performed. By default (i. e., if you don't change any of the parameters), this check box is checked. So if you have three Display blocks, as shown in the top picture, all three will clear the NXT display, and only the last drawing operation will be visible!

So click on the "Clear" check box if you already have drawings on the NXT display, and only want to add more, not start over.