blink_ip.sh

#!/bin/bash

# Copyright 2017 Kirill Snezhko
# MIT License
# Small script that blinks ip-address of your Orange Pi Zero

# blink led red_led
# we need root to do this
function strobe {
    echo 1 > "/sys/class/leds/red_led/brightness"
    sleep $1
    echo 0 > "/sys/class/leds/red_led/brightness"
    sleep $1
}

# display quarter of a ip address
function draw_number {

    # split string to letters
    DIGITS="$(grep -o . <<<$1)"

    # blink every digit
    for DIGIT in ${DIGITS[@]}
    do
        # blink 10 times for zero
        if [$DIGIT == 0]
        then 
            $DIGIT = 10
        fi

        for ((i=1; i<=$DIGIT; i++)); do
            strobe 0.2
        done

        # medium blink between didits
        sleep 1
        strobe 1
    done

    # large blink between quarters
    sleep 2
    strobe 2
}


# get all ip addresses
IPS="$(hostname -I)"

# ready to go?
sleep 5

# IPS is splitted by the whitespace
for IP in $IPS
do
    # replace "." with " " and split again
    QUARTERS=(${IP//./ })

    for QUARTER in ${QUARTERS[@]}
    do
        draw_number $QUARTER
    done
    sleep 1
done

exit 0