FSR Sensor to keep pressure in 7 seconds?

Projects Programming
1

Hello,

I have a FSR sensor, where I need to ensure that it has a pressing value of at least 250 in 7 seconds. The values are not important, but needs to be above 250 in 7 seconds in order to run an other function.

The only thing I got so far is this.

FSRreading = AnalogRead(FSR);

if(FSRreading>250) {

other_function();


}

So this only checks once and execute the other_function. How can I ensure that it has been pressed for 7 seconds?

Thank you in advance :smiley:

2

Record the time the reading first exceeds the threshold.
Use millis().

Take it from there.

3

I've found that the best way to code "Has condition been true for at least 'time'?" is to restart a millis() timer every time the condition is false. Then if the timer reaches 'time' the condition has been true that long.

const byte FSRPin = A0;
const unsigned long SevenSeconds = 7000;

void setup() {}

unsigned long TimerStart;
void loop()
{
  int reading = analogRead(FSRPin);

  if (reading <= 250)
    TimerStart = millis();

  if (millis() - TimerStart >= SevenSeconds)
  {
    // reading has been above 250 for 7 seconds or more
    do_the_thing();

    // Don't do it again unless the reading is high for
    // ANOTHER 7 seconds
    TimerStart = millis();
  }
}

void do_the_thing() {}