LCD Screen countdown timer problem and input problem

Projects Programming
5

I have a countdown timer on my LCD screen, but whenever the counter goes from 100 to 99 it prints 990, 980.

Try something like this...

  for ( n = 110; n > 0; n--) 
    {
    lcd.setCursor(13, 1);
    delay(1000);
    lcd.print(n);
    lcd.print(" ");
    }

This will not work...

  if (plusPin, LOW)

You want something more like...

  if (digitalRead(plusPin) == LOW)

Of course you will still miss pulses until you get rid of the delays. And you probably want to increment the variable on the edge of the pulse, look for the input to change state before taking action. If the pulse is +5V then you should look for the pin to be HIGH to act on the rising edge.