LEGO MINDSTORMS Robots User Manual

while (true) {
if (state == BOTH_ON)
OnFwd(OUT_A + OUT_C);
else if (state == LEFT_ON) {
Off(OUT_A);
OnFwd(OUT_C);
}
else if (state == RIGHT_ON) {
Off(OUT_C);
OnFwd(OUT_A);
}
}
A separate task, watcher, examines the light sensor values and sets the state variable. Here is the entire source code for the two sensor version of Trusty:
int state;
// "ON" refers to whether the light
// sensor is on the line. If it is,
// the light sensor is seeing black.
#define BOTH_ON 3
#define LEFT_ON 1
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#define RIGHT_ON 2
#define BOTH_OFF 0
#define INDETERMINATE 255
// Thresholds for light and dark.
#define DARK2 35
#define LIGHT2 40
#define DARK3 40
#define LIGHT3 45
#define POWER 4
task main() {
initialize();
while (true) {
if (state == BOTH_ON)
OnFwd(OUT_A + OUT_C);
else if (state == LEFT_ON) {
Off(OUT_A);
OnFwd(OUT_C);
}
else if (state == RIGHT_ON) {
Off(OUT_C)
OnFwd(OUT_A);
}
}
}
sub initialize() {
SetSensor (SENSOR_2, SENSOR_LIGHT);
SetSensor (SENSOR_3, SENSOR_LIGHT);

LEGO MINDSTORMS Robots Specifications

General

Product Line	LEGO MINDSTORMS
Category	Toy
Age Range	10+
Batteries Required	Yes
Memory	64 MB RAM, 16 MB Flash
Connectivity	Bluetooth, USB
Sensors	Touch, Color, Gyro
Battery Type	AA
Interactive Features	Programmable, Remote Control
App Compatibility	iOS, Android
Processor	ARM9
Pieces Count	601
Battery Count	6
App Name	LEGO MINDSTORMS EV3 Programmer App