User manual

RP6 ROBOT SYSTEM - 4. Programming the RP6

You may simply build endless loops with while- or for-loops:

while(true) { }

for(;;) { }

In both cases the command block will be executed “for ever” (respectively until the

microcontroller receives an external reset signal or the program terminates the loop

by executing the “break”-instruction).

For the sake of completeness we finish this overview by describing the “do-while”-

loop, which may be considered as an alternative to the standard “while”-loop. In con-

trast to “while-loops the “do-while”-loop will at least execute the command block

once, even if the condition is false at the beginning.

The loop-structure is as follows:

{

}

while(<condition>);

Please remember to place a terminating semicolon! (Of course, standard while loops

will not be terminated with a semicolon at the end!).

4.4.8. Functions

Functions are a key element in programming languages. In the previous chapters we

already met and even used functions, e.g. “writeString”, “writeInteger” and of course

the main-function.

Functions are extremely useful for using identical program sequences at several loca-

tions of a program – the text output functions used in previous chapters are good ex-

amples for this. Copying identical program code to all locations where it is used would

be very unhandy. Additionally, we would unnecessarily waste a lot of program

memory in doing something like this. Using one single function allows us to modify

program modules at a single central location instead of modifying a great number of

copies. Using functions will simplify the program flow and help us to keep the over-

view.

Therefore C allows us to combine program sequences to functions, which are always

structured as follows:

<Return type> <Function name> (<Parameter 1>, <Parameter 2>, ... <Parameter n>)

{

}

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