Simple bash script to control TPLink Kasa dimmers (HS220 for example).

kasa-dimmer.sh

#!/bin/bash
# GNU GPLv2
# Simple bash script to control TPLink Kasa dimmers (HS220 for example).
# Turn on or off Kasa dimmer:   KASA_HOST=192.168.1.2 ./dimmer
# Set brightness of the dimmer: KASA_HOST=192.168.1.2 ./dimmer [1-100]

KASA_HOST=${KASA_HOST:-192.168.1.144}
if ! which kasa &> /dev/null; then
    echo "ERROR: The kasa executable is required, see https://github.com/python-kasa/python-kasa"
    exit 1
fi
if [[ -n $1 ]]; then
    if [[ $1 =~ ^[0-9]* ]] && [[ $1 -gt 0 ]] && [[ $1 -le 100 ]]; then
        kasa --host "$KASA_HOST" brightness "$1" &> /dev/null &
        exit 0
    fi
    echo "ERROR: Brightness must be a number in the range of 1 to 100."
    exit 1
fi
state=$(kasa --host "$KASA_HOST" state | grep -m1 "Device state: O" | cut -d: -f2)
if [[ ! $state =~ (ON|OFF) ]]; then
    echo "ERROR: Problem querying the dimmer."
    exit 1
fi
[[ $state =~ OFF ]] && state=on || state=off
kasa --host "$KASA_HOST" "$state" &> /dev/null &