output dependant on 2 inputs.

I am trying to put together a project that when both a microphone and a pressure sensor both give a peak reading a output is triggered however at present i am experimenting with simple push buttons before using analog inputs.

what I am trying to achieve is that when both buttons are pressed or pressed within a given time of each other (ie. one button is pushed and the other is pushed within 2 seconds) that an event is triggered.

any help at all getting this to work with at least the buttons would be greatly appreciated.

so far this is what i have, but have been having trouble getting the two buttons to operate independently, the LedPins are currently just being used for testing purposes. I havnt got this far yet but the intention was that when both counters = 1 they would trigger an event.

int buttonPin1 = 1; int buttonPin2 = 2; int ledPin1 = 9; int ledPin2 = 10;

int counter1 = 0; //using a counter to determine button state int counter2 = 0;

int buttonState1; int buttonState2;

void setup(){

pinMode(buttonPin1, INPUT); pinMode(buttonPin2, INPUT); pinMode(ledPin1, OUTPUT); pinMode(ledPin2, OUTPUT); }

void loop(){ buttonState1 = digitalRead(buttonPin1); buttonState2 = digitalRead(buttonPin2);

if (buttonState1 == HIGH){ counter1++; if (counter1 >1){ counter1 = 0; } } if(buttonState2 == HIGH){ counter2++; if (counter2 >1){ counter2 = 0; } } if (counter1 == 1){ digitalWrite(ledPin1, HIGH); } else if(counter1 != 1){ digitalWrite(ledPin1, LOW); } if (counter2 == 1){ digitalWrite(ledPin2, HIGH); } else if(counter2 != 1){ digitalWrite(ledPin2, LOW); } if(counter1 ==1){ //this part had the intention of resetting each counter to 0 after 1 second. delay(1000); counter1--; } if(counter2 ==1){ delay(1000); counter2--; }

}

check millis(),
you can make a timestamp with that when an event occurs, in pseudo code

unsigned long TS1 = 0;
unsigned long TS2 = 0;

if (button1 is pressed) TS1 = millis();
if (button2 is pressed) TS2 = millis();

if ((TS1 != 0) && (TS2 != 0) && (abs(TS1 - TS2) < 2seconds))
{
   do event;
}

get it?

I think you can do it a lot simpler than keeping track of states and counters. Something like

unsigned long t_event1;
unsigned long t_event2;


if (event1_happened())
	t_event1 = millis();

if (event2_happened())
	t_event2 = millis();
	
if (t_event1 - t_event2 < 2000)
    // both events happened within 2 seconds

Rob

Had a quick go and got stuck with “< 2seconds”

sorry all of this is very new to me. is this getting closer to what i need?

int buttonPin1 = 1;
int buttonPin2 = 2;
int ledPin1 = 9;
int ledPin2 = 10;


int buttonState1;
int buttonState2;

unsigned long TS1 = 0;
unsigned long TS2 = 0;

void setup(){


  pinMode(buttonPin1, INPUT);
  pinMode(buttonPin2, INPUT);
  pinMode(ledPin1, OUTPUT);
  pinMode(ledPin2, OUTPUT);
}

void loop(){

 buttonState1 = digitalRead(buttonPin1);
buttonState2 = digitalRead(buttonPin2);
  
if (buttonState1 ==HIGH){
  TS1 = millis();
}

if (buttonState2 == HIGH){
  TS2 = millis();
}

if ((TS1 != 0) && (TS2 != 0) && (abs(TS1 - TS2) < 2seconds))
{
    digitalWrite(ledPin1, HIGH);
  }
  else{
    digitalWrite(ledPin1, LOW);
}

}

Read up on the millis() function then look at my version, that should give you a hint.

Both Rob and I were showing pseudo code, it’s not supposed to work out of the box.


Rob

@Rob

if (t_event1 - t_event2 < 2000)
// both events happened within 2 seconds

If both are zero (just after init) this condition is also true :wink:

Yeah I noticed your extra test for that gotcha.


Rob