Driving Example

Here is the Java code (method only) for converting an inches of driving target into an encoder counts target. The conversion depends on the drive motors’ counts-per-rotation (CPR), and the diameter of the drive wheels. This example assumes 1:1 gear ratio between the motor and wheel.

This method takes three inputs from the Blocks user, and returns one output (of type int or integer) to the regular Block that calls the myBlock.

Tip

Notice the calculation uses the variable or constant named PI, from the inherited class Math. This holds the fixed numeric value 3.14159….

Here is an example of typical usage.

Tip

Notice the (int) operator at the return command. This converts or casts the countsToDrive variable of type double to type int, to be compatible with the required return type. Learn more about type casting here or here.

As programmer, you could modify this example in many ways, such as: - handle a gear ratio between the drive motors and wheels - the second and third parameters could be ‘hard-coded’ into the myBlock, if they will never change - those 2 variables could be initialized in a non-myBlock method and used by multiple myBlock methods in that same Java class