Trouble with obstacle avoiding robot

Other Hardware Robotics
4

Hi,
Why use Ping.h? can't understand it, the basic code is so simple and for me works everytime.

Here's some code cut from one of my programs:

ong scanner(long cm)
{
	const int pingPin=7, EchoPin=8;
	long duration;

	// The SRF005/HC-SR04 is triggered by a HIGH pulse of 2 or more microseconds.
	// Give a short LOW pulse before to ensure a clean HIGH pulse:
	pinMode(pingPin, OUTPUT);
	pinMode(EchoPin, INPUT);  

	digitalWrite(pingPin, LOW);
	delayMicroseconds(2);
	digitalWrite(pingPin, HIGH);
	delayMicroseconds(2);
	digitalWrite(pingPin, LOW); 
	duration = pulseIn(EchoPin, HIGH);
	delay(100);

	// convert the time into a distance
	// inches = microsecondsToInches(duration);
	cm = microsecondsToCentimeters(duration);
	return (cm);
}
//------------------------------------------------------------------
long microsecondsToCentimeters(long microseconds)
{
	// The speed of sound is 340 m/s or 29 microseconds per centimeter.
	// The ping travels out and back, so to find the distance of the
	// object we take half of the distance travelled.
	return microseconds / 29 / 2;
}

void Radar()
{
	Halt();
	BackOff();
	Lturn();
	sound(2200,20);
	Halt();
	A=scanner(cm);
	delay(100);
	Rturn();
	Rturn(); 
	sound(2200,20);
	Halt();
	B=scanner(cm);
	delay(100);
	Lturn();
	delay(50);

	if (A>B) 
	{
		Lturn();  //Then turn left
		A=0; 
	}
	else  
	{
		Rturn();  //Then turn right
		B = 0;
	}
}

By the way the L329/L398 are poor drivers as you lose power (2v+) on the output transistors use something with FET outputs, more power... You have called the motors A & B that's fine so why not call the pins MA- MA+ makes sense!

Hope it helps, regards. (see www.melsaunders.co.uk for my bots)

Mel.