#!/usr/bin/env bash

HOME_IP=10.11.12.13
notified_off=false
notified_on=false

while sleep 60 ; do
    if ping -c1 -w3 "$HOME_IP" >/dev/null 2>&1 ; then
        if [ notified_on = 'false' ] ; then
            notified_on = 'true'
            notified_off = 'false'
            termux-notification -c 'Power is ON'
        fi
    else
        if [ notified_off = 'false' ] ; then
            notified_off = 'true'
            notified_on = 'false'
            termux-notification -c 'Power is OFF'
        fi
    fi
done