How to separate program into functions?

HoTWiReZ · Fri Mar 16, 2007 9:21 am

Hi, I've been trying to make a simple program I based on the motortest.c into a function to use as part of a main program. I created a file, Procedures.h, that contains the function declaration for the method,
int FindAngle(int& distance). I made a main.c, which is short enough to show here:


	Code: #include "Procedures.h" task main() { int distance = 0; int Angle = FindAngle(distance); nxtDisplayTextLine(1,"Angle Found:%d",Angle); nxtDisplayTextLine(2,"Distance:%d",distance); wait10Msec(1000); }

I get this RCX Exception Violation Report when the debugger gets to the 2nd line inside of main..

Byte Code Interpreter Exception:

Program Slot: 0, Task ID: main[0]
Error at PC: BAD-LOC +0xD51C
Task PC: Task offset 000E,
TaskState: 'Exception'
Exception Type: 'Invalid opcode(11)'

Also, I tried to just include the function above the main as a free function, but the same error happens when it's called. Here's the whole thing when I do it this way, just in case there is comething else wrong with this that's causing the error..


	Code: //This function should be called when the robot encounters an obstacle. //It will check left and right for an edge up to 75 degrees away from //center. The function returns the angle from center (left is +, right //is -) and returns the distance at which the edge was measured as it //is passed by reference. int FindAngle(int& distance) { //Declared as RAM values int nMoveSize = 5; int nSpeed = 100; int nDelay = 500; int SensorVal = 255; int SensorValOld = 255; bool FoundEdge = false; int LeftEdge = 0; int RightEdge = 0; int LeftDistance = 0; int RightDistance = 0; int sumVals = 0; int i = 0; //Loop counter const tSensors sonarSensor = (tSensors) S4; //sensorSONAR9V const tSensors lightSensor = (tSensors) S3; //reflected Light Sensor SensorType[sonarSensor]=sensorSONAR9V; SensorType[lightSensor]=sensorLightActive; bFloatDuringInactiveMotorPWM = false; nMotorEncoder[motorA] = 0; //Checking to the left for an edge while (nMotorEncoder[motorA] < 75 && FoundEdge==false) { nMotorEncoderTarget[motorA]=nMoveSize; motor[motorA]=nSpeed; wait1Msec(nDelay/2); SensorValOld=SensorVal; //Trying to normalize values here to help avoid bad values.. sumVals = 0; for (i=0; i<100; i++) { sumVals+=SensorRaw(sonarSensor); } SensorVal=sumVals/100; wait1Msec(nDelay/2); if (SensorVal>=SensorValOld+10) { FoundEdge=true; LeftEdge=nMotorEncoder[motorA]; LeftDistance=SensorValOld; } } //Move back to center, ignoring Sonar values while (nMotorEncoder[motorA] > 0) { nMotorEncoderTarget[motorA]=nMoveSize; motor[motorA]=nSpeed(-1); wait1Msec(nDelay); } //Return SensorVals to defaults.. SensorVal=255; SensorValOld=255; FoundEdge=false; //Find edge on Right side while (nMotorEncoder[motorA] > -75 && FoundEdge==false) { nMotorEncoderTarget[motorA]=nMoveSize; motor[motorA]=nSpeed(-1); wait1Msec(nDelay/2); SensorValOld=SensorVal; //Trying to normalize values here to help avoid bad values.. sumVals = 0; for (i=0; i<100; i++) { sumVals+=SensorRaw(sonarSensor); } SensorVal=sumVals/100; wait1Msec(nDelay/2); if (SensorVal>=SensorValOld+10) { FoundEdge=true; RightEdge=nMotorEncoder[motorA]; RightDistance=SensorValOld; } } //Return to 0 degrees and return SensorVals to defaults while (nMotorEncoder[motorA] < 0) { nMotorEncoderTarget[motorA]=nMoveSize; motor[motorA]=nSpeed; wait1Msec(nDelay); } SensorVal=255; SensorValOld=255; if ((RightEdge-1)<LeftEdge) { distance=RightDistance; return RightEdge; } else if (LeftEdge<(RightEdge-1)) { distance=LeftDistance; return LeftEdge; } } task main() { int distance = 0; int Angle = FindAngle(distance); nxtDisplayTextLine(1,"Angle Found:%d",Angle); nxtDisplayTextLine(2,"Distance:%d",distance); wait10Msec(1000); }

I'm assuming that this means that I can't do what I'm trying to do? If I can, what am I doing wrong here? If not, is there an equivalent way to handle this?
Thanks.

How to separate program into functions?

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