blinky/scripts/blinky-feed.sh

#!/usr/bin/env bash

# author:	Daniel Sommer <daniel.sommer@velvettear.de>
# license: 	MIT

# blinky 
blinky_url="127.0.0.1:3000"
blinky_mode="morph"
blinky_duration="2500"

# temperature
max_temp="65000"
crit_temp="70000"
threshold_upper="66"
threshold_lower="33"
thermal_zones=(
    "3"
)

# argument to lowercase
arg="${1,,}"

# functions

function checkRoot() {
    [[ "$EUID" != 0 ]] && printf "error: permission denied!\n" && exit 1
}

# convert a temperature value to a rgb color value
function temperatureToRGB() {
    [[ ! "$1" ]] && printf "error: did not receive a temperature value to convert to a rgb value\n" && exit 1
    printf "converting temperature to rgb value... "
    percentage="$(bc <<< "$1 / ( $max_temp / 100 )")"
    [[ "$percentage" -gt "100" ]] && percentage="100"
    color_main="$(bc <<< "$percentage * 2.55")"
    color_supplement="$(bc <<< "255 - $color_main")"
    color_unused="0"
    if [[ "$percentage" -ge "$threshold_upper" ]]; then
        result="$color_main, $color_supplement, $color_unused"
    elif [[ "$percentage" -ge "33" ]]; then 
        result="$color_supplement, $color_main, $color_unused"
    else 
        result="$color_unused, $color_supplement, $color_main"
    fi 
    printf "result: '$result'\n"
}

# send http post request to blinky
function sendPOST() {
    [[ ! "$1" ]] && printf "error: did not receive any arguments for post request\n" && exit 1  
	cmd="curl -X POST" 
	for arg in "$@"; do
		cmd="$cmd -d \"$arg\""
	done
	cmd="$cmd \"$blinky_url\""
	printf "sending post request '$cmd'...\n"
	eval "$cmd"
}

# get (average) temperature from defined thermal zones
function getTemperature() {
	counter="0"
    printf "getting temperature value from thermal zone(s) "
	for zone in "${thermal_zones[@]}"; do
        printf "'"$zone"'... "
        for value in $(cat "/sys/devices/virtual/thermal/thermal_zone"$zone"/temp"); do
            [[ ! "$temp" ]] && temp="$value" || temp=$(( $temp + $value ))
            (( counter++ ))
        done
    done
    result="$(( $temp / $counter ))"
    printf "result: '$result'\n"
    [[ "$result" -ge "$crit_temp" ]] && printf "warning: critical temperature reached\n" && blinky_mode="pulse" && blinky_duration="500" && return 0
    [[ "$result" -ge "$max_temp" ]] && printf "warning: maximum temperature reached\n" && blinky_mode="pulse" && blinky_duration="1500" && return 0
}

# main part
case "$arg" in
	-t|--temp|--temperature)
        checkRoot
		getTemperature
		temperatureToRGB "$result"
		sendPOST "color=$result" "mode=$blinky_mode" "duration=$blinky_duration"
		;;
	*)
		printf "error: no argument given or argument unknown!\n" && exit 1
		;;
esac