#!/bin/bash

PIN=4

if [ ! -e /sys/class/gpio/gpio$PIN ]
then
  echo "$PIN" > /sys/class/gpio/export
fi

echo "in" > /sys/class/gpio/gpio$PIN/direction

previous=$(cat /sys/class/gpio/gpio$PIN/value)
timer=0

while true
do
  pin=$(cat /sys/class/gpio/gpio$PIN/value)

  if [ $pin -gt $previous ]
  then
    now=$(date +%s)

    if [ $now -gt $timer ]
    then
      echo "$(date '+%d.%m.%Y %H:%M')" >> /var/www/log.txt
      echo "$(date '+%d.%m.%Y %H:%M')"
    fi

    (( timer = now + 120 ))
  fi

  previous=$pin
  sleep 0.5
done