Detect if analog voltage input drops for duration of time

Projects Programming
1

Hi all
My script currently outputs HIGH/LOW to pin 13 when analog voltage input is above or below 5v

I'm trying to figure out how to only output low if voltage input drops below 5v for 5 seconds

Here's what I currently have

/*

int analogInput = 1;
float vout = 0.0;
float vin = 0.0;
float R1 = 10000.0; // resistance of R1 (100K)
float R2 = 1000.0; // resistance of R2 (10K) 
int value = 0;
unsigned long time;

void setup() {
  //start serial connection
  Serial.begin(9600);
  analogReference(INTERNAL);
  pinMode(13, OUTPUT);
  delay(500);

}
void loop(){

  
   // read the value at analog input
   value = analogRead(analogInput);
   vout = (value * 1.1) / 1024.0; 
   vin = vout / (R2/(R1+R2)); 
   if (vin<0.09) {
   vin=0.0;//statement to quash undesired reading 
} 

if (vin>5) {
    digitalWrite(13, HIGH);
  } else {
    
    digitalWrite(13, LOW);
  }
   
  Serial.println(vin);

}

Thanks in advance

2

The simplest way is to think of the problem upside down. Record the time whenever the value is HIGH and then check how long since it was last HIGH - like this

if (value == HIGH) {
   timeValueLastHigh = millis();
}

if (millis() - timeValueLastHigh >= 5000) {
   // value has been low for 5 secs
   // do stuff
}

...R

3

Robin2:
The simplest way is to think of the problem upside down. Record the time whenever the value is HIGH and then check how long since it was last HIGH - like this

if (value == HIGH) {

timeValueLastHigh = millis();
}

if (millis() - timeValueLastHigh >= 5000) {
  // value has been low for 5 secs
  // do stuff
}




...R

Brilliant! I knew it would be simple. Works perfectly, thanks