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[on:]

I have wired a microswitch to Pin 1 of the Mega. I need to use it as ON/OFF toggle to drive a load through TIP122, and display the time load was switched ON for. Can someone help me in modifying the Toggle LED code to measure time (in seconds) between ON/OFF?
Thanks!!

Code:

int inPin = 2;         // the number of the input pin
int outPin = 13;       // the number of the output pin

int state = LOW;      // the current state of the output pin
int reading;           // the current reading from the input pin
int previous = LOW;    // the previous reading from the input pin

// the follow variables are long's because the time, measured in miliseconds,
// will quickly become a bigger number than can be stored in an int.
long time = 0;         // the last time the output pin was toggled
long debounce = 200;   // the debounce time, increase if the output flickers
long dur_on = 0;    //the duration between ON/OFF

void setup()
{
  pinMode(inPin, INPUT);
  pinMode(outPin, OUTPUT);
  Serial.begin(9600);
}

void loop()
{
  reading = digitalRead(inPin);
  // if the input just went from LOW and HIGH and we've waited long enough
  // to ignore any noise on the circuit, toggle the output pin and remember
  // the time
  if (reading == HIGH && previous == LOW && millis() - time > debounce) {
    if (state == HIGH)
      state = LOW;
    else
      state = HIGH;


  }
  dur_on = (millis() - time)/1000;
  Serial.println(dur_on);
  digitalWrite(outPin, state);


  previous = reading;
}

[Reply #1 on:]

Use millis() to record the time it was pressed. On the next press subtract that time from the new value of millis() to get the time elapsed

[Reply #2 on:]

Where in the code do I use millis()??

[Reply #3 on:]

Where in the code do I use millis()??

Where you want to know when something happened.

[Reply #4 on:]

If I understand your question right, this might do the trick. I just added some code to your loop.
I didn't run this, there could be a bug or a problem with my logic, however something like this
might steer you in the direction you're looking to go:

Code:

int inPin = 2;         // the number of the input pin
int outPin = 13;       // the number of the output pin

int state = LOW;      // the current state of the output pin
int reading;           // the current reading from the input pin
int previous = LOW;    // the previous reading from the input pin

// the follow variables are long's because the time, measured in miliseconds,
// will quickly become a bigger number than can be stored in an int.
long time = 0;         // the last time the output pin was toggled
long debounce = 200;   // the debounce time, increase if the output flickers
long dur_on = 0;    //the duration between ON/OFF

void setup()
{
  pinMode(inPin, INPUT);
  pinMode(outPin, OUTPUT);
  Serial.begin(9600);
}

void loop()
{
reading = digitalRead(inPin);

// if the input just went from LOW and HIGH and we've waited long enough
// to ignore any noise on the circuit, toggle the output pin and remember
// the time
if (reading == HIGH && previous == LOW && millis() - time > debounce)
{
time = millis();

if (state == HIGH)
state = LOW;
else
state = HIGH;
}

// if the input is high then remember the time and print duration
// else ignore time reading and continue with loop
if ((reading == HIGH) && (millis() - time > debounce))
{
dur_on = (millis() - time)/1000;
Serial.println(dur_on);
}

digitalWrite(outPin, state);


previous = reading;
}

[Reply #5 on:]

Thanks Postholes!

[Reply #6 on:]

You know that your accuracy will be no better than 2x the switch debounce?

If you need better then perhaps think about light beam interrupt or other short-or-no-bounce sensor?

 

[Reply #7 on:]

You know that your accuracy will be no better than 2x the switch debounce?

If you need better then perhaps think about light beam interrupt or other short-or-no-bounce sensor?

 

It's not a high accuracy application, so I am using the Bounce library to debounce for about 200ms.. That serves the purpose

[Reply #8 on:]

it could help?

Code:

const int inPin = 2;
const int outPin= 13;
int elapsedtime=0;

int ledstate =LOW;
int switchstate = LOW;
int previous = LOW;

long prevtime = 0;
long debounce = 200;
long dur_on = 0; //duration between on/off

void setup(){
  pinMode(inPin,INPUT);
  pinMode(outPin,OUTPUT);
  Serial.begin(9600);
}

void loop(){

  switchstate=digitalRead(inPin);
  if ((millis()-prevtime)>debounce){
    if(switchstate!=previous && switchstate==HIGH){
      if (ledstate==LOW){
        digitalWrite(outPin,HIGH);
        prevtime=millis();
        ledstate=HIGH;
      }
      else if(ledstate==HIGH){
        digitalWrite(outPin,LOW);
        ledstate=LOW;
        Serial.print("time between On and off state");
        elapsedtime=((millis()-prevtime)/1000);
        Serial.println(elapsedtime);
         prevtime=millis();
      }
    }
  }
}
     
       
 

it works, but the value printed in the serial monitor, is always an integer, and even initializing the "elpasedttime" as a float, always ineger values are returned.

[Reply #9 on:]

You know that your accuracy will be no better than 2x the switch debounce?

If you need better then perhaps think about light beam interrupt or other short-or-no-bounce sensor?

 

It's not a high accuracy application, so I am using the Bounce library to debounce for about 200ms.. That serves the purpose

It is -only- a problem if you expect more accuracy. I meant that in a goal-engineering sense.

[Reply #10 on:]

it works, but the value printed in the serial monitor, is always an integer, and even initializing the "elpasedttime" as a float, always ineger values are returned.

You are subtracting one integer value from another, and dividing the integer result by an int. Why you would expect a non-integer result is the mystery. Now, if you divided by 1000.0, instead...