Page 83 - The Unofficial Guide to Lego Mindstorms Robots
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count++;
until(SENSOR_1 == 0);
}
}
W hen you run this program, you'll notice the RCX shows the status of the datalog on the right side of the display. It looks kind
of like a pie; as you add values to the datalog the pie fills up.
T o upload a datalog to th e PC, you can use nqc's -datalog option, which simply dumps the values to the screen:
C:\>nqc -datalog
8
12
16
19
23
25
27
29
31
33
39
47
52
56
5 9
62
65
68
71
75
C:\>
The datalog actually stores the source of ever y value. If you use a tool like RCX Command Center, it can show you the source
of each value in the datalog. In Chapter 8, Using Spirit.ocx w ith Visual Basic, I'll show you how to write your own program in
Visual Basic to retrieve the contents of the d atalog.
Tasks
NQC gives you powerful control over tasks and subroutines. Each of the RCX's five programs is made up of one or more
tasks. These tasks can execute at the same time, which is another way of saying that the RCX is multitasking.
Tasks are defined using the task comma nd. Every program must have a main task which is executed when the program is
first started. Other tasks must be started and stopped explicitly:
