Hello, Im working on a project where I want to count cars coming in and out of a parking area.
I have modified the example ping code and used the ping distance as a way to count up or down, the problem i am running into is that when I run them at the same time the counter only counts down
here is my code so far.
/* Ping))) Sensor
This sketch reads a PING))) ultrasonic rangefinder and returns the
distance to the closest object in range. To do this, it sends a pulse
to the sensor to initiate a reading, then listens for a pulse
to return. The length of the returning pulse is proportional to
the distance of the object from the sensor.
The circuit:
* +V connection of the PING))) attached to +5V
* GND connection of the PING))) attached to ground
* SIG connection of the PING))) attached to digital pin 7
http://www.arduino.cc/en/Tutorial/Ping
created 3 Nov 2008
by David A. Mellis
modified 30 Aug 2011
by Tom Igoe
This example code is in the public domain.
*/
// this constant won't change. It's the pin number
// of the sensor's output:
const int pingPin = 7;
const int pingPin2 = 8;
int count = 6;
void setup() {
// initialize serial communication:
Serial.begin(9600);
}
void loop()
{
// establish variables for duration of the ping,
// and the distance result in inches and centimeters:
long duration, inches, cm;
long duration2, inches2, cm2;
// The PING))) is triggered by a HIGH pulse of 2 or more microseconds.
// Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
pinMode(pingPin, OUTPUT);
digitalWrite(pingPin, LOW);
delayMicroseconds(2);
digitalWrite(pingPin, HIGH);
delayMicroseconds(5);
digitalWrite(pingPin, LOW);
pinMode(pingPin2, OUTPUT);
digitalWrite(pingPin2, LOW);
delayMicroseconds(2);
digitalWrite(pingPin2, HIGH);
delayMicroseconds(5);
digitalWrite(pingPin2, LOW);
// The same pin is used to read the signal from the PING))): a HIGH
// pulse whose duration is the time (in microseconds) from the sending
// of the ping to the reception of its echo off of an object.
pinMode(pingPin, INPUT);
duration = pulseIn(pingPin, HIGH);
pinMode(pingPin2, INPUT);
duration2 = pulseIn(pingPin2, HIGH);
// convert the time into a distance
inches = microsecondsToInches(duration);
cm = microsecondsToCentimeters(duration);
inches2 = microsecondsToInches(duration2);
cm = microsecondsToCentimeters(duration2);
if(inches < 20)
{
count++;
}
else(inches2 < 20);
{
count--;
}
Serial.print(inches);
Serial.print("in, ");
Serial.print(cm);
Serial.print("cm");
Serial.println();
Serial.print("Count");
Serial.println(count);
Serial.print(inches2);
Serial.print("in, ");
Serial.print(cm2);
Serial.print("cm");
Serial.println();
Serial.print("Count");
Serial.println(count);
delay(500);
}
long microsecondsToInches(long microseconds)
{
// According to Parallax's datasheet for the PING))), there are
// 73.746 microseconds per inch (i.e. sound travels at 1130 feet per
// second). This gives the distance travelled by the ping, outbound
// and return, so we divide by 2 to get the distance of the obstacle.
// See: http://www.parallax.com/dl/docs/prod/acc/28015-PING-v1.3.pdf
return microseconds / 74 / 2;
}
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;
}