See if condition last for 2 minutes

Projects Programming
1

I have a simple sketch to open a door when sensor (light sensor) is open and close if closed. Pin 10 stops closing (micro switch).

void setup() {
pinMode(9,OUTPUT ); //Brake
pinMode(12,OUTPUT ); //HIGH is forward
pinMode(8, INPUT); //light sensor
pinMode(10, INPUT); //micro swich
}

void loop() {

if (digitalRead(8)==HIGH && digitalRead(10)==LOW) {
digitalWrite(9, LOW);
digitalWrite(12, LOW);
analogWrite(3, 255);
}
else {
digitalWrite(9, HIGH);
}
if (digitalRead(8)==LOW && digitalRead(10)==LOW) {
digitalWrite(9, LOW);
digitalWrite(12, HIGH);
analogWrite(3, 255);
}
else {
digitalWrite(9, HIGH);
}
}
How check that light sensor is open/closed for a while (2 minutes) to avoid accidental initiation by mistake (light beam og shadow)?

2

The easier you make it to read and copy your code the more likely it is that you will get help

Please follow the advice given in the link below when posting code , use code tags and post the code here

If you get errors when compiling please copy them from the IDE using the "Copy error messages" button and paste the clipboard here in code tags

3

Save the value of millis() when the start action occurs and set a boolean to true to indicate that timing is taking place.

Each time through loop(), if the boolean is true then test whether the required period has elapsed by subtracting the start value from the current value of millis(). If so, act accordingly.

If the start action is cancelled before the period elapses then set the boolean to false

4

Timing tutorials:
Several things at a time.
Beginner's guide to millis().
Blink without delay().

5

general tips:

Give all and every IO-Pin and all variables a selfexplaining name.
Give all functions a self-explaining name

This will make it much easier for you and of course all your potential helpers
to understand your code
There are some habits for the naming
variables start with a low-case-letter

So for example instead of adding comments like this

void setup() {
  pinMode(9,OUTPUT ); //Brake  
  pinMode(12,OUTPUT ); //HIGH is forward  
  pinMode(8, INPUT); //light sensor
  pinMode(10, INPUT); //micro swich
}

You can define constants and variables with self-explaining names
const byte Brake_Pin = 9;
const byte Direction_Pin = 12;

const byte lightSensor_Pin = 8;
const byte microSwitch_Pin = 10;

#define HOLD HIGH
#define LOOSE LOW

#define FORWARD HIGH
#define BACKWARD LOW

void setup() {
  pinMode(Brake_Pin,OUTPUT ); 
  pinMode(Direction_Pin,OUTPUT ); 
  pinMode(lightSensor_Pin, INPUT); 
  pinMode(microSwitch_Pin, INPUT); 
}


void loop() {

  if (digitalRead(lightSensor_Pin) == HIGH && digitalRead(microSwitch_Pin) == LOW) {
    digitalWrite(Brake_Pin, LOOSE);
    digitalWrite(Direction_Pin, BACKWARD);
    analogWrite(3, 255); // what is IO-pin 3  ????
  }
  else {
    digitalWrite(Brake_Pin, HOLD);
  }

best regards Stefan

1 Like
6

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