Hi all
I have built an infrared light barrier. It is connected with "sensePin".
I want the Arduino to count objects passing the barrier.
The problem:
The program I have, counts while an object is passing the barrier.
That means if the object need a lot of time to pass, the counter will display a high number.
My try to solve:
I said the arduino to wait until the object passed, after it added 1. Pseudocode:
add 1;
write number on the display;
while(object in the barrier)
do nothing;
The arduino stopped to count after 1 object passed the barrier. =(
Thank you for helping!
[//* * Tastendrücke zählen */
#include <LiquidCrystal.h>
LiquidCrystal lcd(12,11,10,7,6,5,4); //Pins für Disply werden festgelegt
//ir
int sensePin= 1; //Anschluss Fototransistor
int ausloeser= 13; //Ausloeser um 1 weiter zu zaehlen
int senseValue; //Wert des analogen Signals
int switchPin = 1; // Schalter ist mit Pin 1 verbunden
int val; // Variable für den Pin Zustand
int buttonState; // Variable für den letzten Schalterzustand
int buttonPresses = 0; // Wie oft ist der Schalter gedrückt
void setup()
{ pinMode(switchPin, INPUT); // Schalter-Pin ist Input
Serial.begin(9600); // Start der seriellen Kommunikation mit 9600bps
buttonState = digitalRead(switchPin); // Anfangszustand lesen
lcd.begin(16,4);
lcd.setCursor(0,0);
lcd.print("100% i.O. Dobry");
}
void loop()
{ senseValue = analogRead(sensePin);
if (senseValue < 50)
{ // Der Zustand des Schalters hat sich verändert
buttonPresses++; // Inkrementieren der Variablen buttonPresses
Serial.print("Schalter wurde ");
Serial.print(buttonPresses);
Serial.println(" gedrueckt");
lcd.setCursor(0,1);
lcd.print (buttonPresses);
}
}]
You need to detect transitions - something is in front of the sensor now but was not last time, or nothing is in front of the sensor now but was last time. Take action (count the object) only when a transition occurs. It is up to you to decide which transition to count.
Detecting transitions means that you need to keep track of the state/value last time.
I tried it already with a structure like this (code). But i can't us edge detection because the sense value of the infrared receiver is changing every milisecond.
[/void loop() {
// read the pushbutton input pin:
buttonState = analogread(sensePin);
// compare the buttonState to its previous state
if (buttonState != lastButtonState) {
// if the state has changed, increment the counter
if (buttonState <50) {
// if the current state is HIGH then the button
// wend from off to on:
buttonPushCounter++;
Serial.println("on");
Serial.print("number of button pushes: ");
Serial.println(buttonPushCounter);
}
}
// save the current state as the last state,
//for next time through the loop
lastButtonState = buttonState;
]
So, you have a big jump when an object passes in front of the sensor, then a little jitter while it is there, and then a big drop when the object is no longer in front of the sensor?
Thanks a lot Nick Gammon and everyone else.