PiShutdownKasa

This method allows you to turn off a Kasa smart device upon shutdown of your raspberry pi. This guide has been tested on the KP115 smartplug, a list of potential compatible devices (that have the timer function) is listed below.

The method used here was taken from this discussion on the python-kasa github. I'm no expert but this is the method I was able to figure out that worked for me.

The reason needed to create this for my setup is because my raspberry pi controls a 3D printer and when I shutdown the pi I then have to turn off the printer manually (turning the power off on a raspberry pi without properly shutting down can lead to SD card corruption), instead of purchasing a relay board and configuring that into the setup I thought I could use my Kasa smartplug to do the job (its essentially a wifi relay).

Potentially compatible devices: RE270K , HS100P3 , EP40 , HS107 , HS105 KIT , HS103 , HS300 , KP115 , HS105 , KD110 , HS110 KIT , HS220 , HS200 , HS100 , RE370K , KP100 , KP400 , KP125 , KP200 , HS100 KIT , KP105 , HS210 KIT , KP303 , HS110 , HS210 - Source

Prerequisite

• Your Kasa smartplug should already be setup and working on your network. Preferably with a static IP set in your router settings.
• There is an alias feature where you can name your device so that you don't have to use the IP address but I will not be using that method that in this guide. But if you want to you can set an alias with kasa --host 192.168.xx.xx alias AliasNameHere, then after it is set you can replace --host 192.168.xx.xx in this guide with --alias AliasNameHere.

Step 1

Install python-kasa

Step 2

To search your network for the smart plug, use the command: kasa discover

$ kasa discover
Discovering devices on 255.255.255.255 for 3 seconds
== MyOutlet - KP115(US) ==
        Host: 192.168.xx.xx
        Device state: OFF

        == Generic information ==
        Time:         2023-01-07 01:01:01 (tz: {'index': 18, 'err_code': 0}
        Hardware:     1.0
        Software:     1.0.18 Build 210910 Rel.141202
        MAC (rssi):   XX:XX:XX:XX:XX:XX (-26)
        Location:     {'latitude': XX.XXXX, 'longitude': XX.XXXX}

        == Device specific information ==
        LED state: True
        On since: None

        == Current State ==
        <EmeterStatus power=0.0 voltage=121.682 current=0.0 total=0.151>

        == Modules ==
        + <Module Schedule (schedule) for 192.168.xx.xx>
        + <Module Usage (schedule) for 192.168.xx.xx>
        + <Module Antitheft (anti_theft) for 192.168.xx.xx>
        + <Module Time (time) for 192.168.xx.xx>
        + <Module Cloud (cnCloud) for 192.168.xx.xx>
        + <Module Emeter (emeter) for 192.168.xx.xx>

• Configure a countdown rule on the outlet (KP115 only allows 1 countdown rule)

First we get a list of the current rule(s) on our specific device
Use the command kasa --host 192.168.xx.xx raw-command count_down get_rules, replace 192.168.xx.xx with the IP of the device.

$ kasa --host 192.168.xx.xx raw-command count_down get_rules
No --type defined, discovering..
{'rule_list': [{'id': 'A553DCB49A54401399DB130F9E589D5C', 'name': 'turnoff45s', 'enable': 0, 'delay': 0, 'act': 0, 'remain': 0}]}

If no rules are found we have to create one, otherwise skip to editing the rule

$ kasa --host 192.168.xx.xx raw-command count_down add_rule '{"enable": 0, "delay": 45, "act": 0, "name": "turnoff45s"}'
No --strip nor --bulb nor --plug given, discovering..
{'id': 'A553DCB49A54401399DB130F9E589D5C'}

id: is the rule ID given upon creation of a new rule.
enable: determines if the rule is enabled, 0 = disabled, 1 = enabled.
delay: is how long in seconds to run the timer. Ex: delay: 45 would be 45 second countdown.
act: determines if the rule turns on the outlet or turns it off, 0 = OFF, 1 = ON.
name: allows you to give the rule a name.

If we already had a rule then we edit the rule

$ kasa --host 192.168.xx.xx raw-command count_down edit_rule '{"id":"A553DCB49A54401399DB130F9E589D5C","enable": 0, "delay": 45, "act": 0, "name": "turnoff45s"}'

Step 3

Now we create a script that will update the rule to enable the timer

$ cd ~
$ nano turnOffOutlet.sh

Contents of turnOffOutlet.sh

#!/bin/bash

#Check to see if the outlet is currently turned on, no need to turn it off otherwise.
if kasa --host 192.168.xx.xx state | grep -q 'Device state: ON'; then
        kasa --host 192.168.xx.xx raw-command count_down edit_rule '{"id":"A553DCB49A54401399DB130F9E589D5C","enable": 1, "delay": 45, "act": 0, "name": "turnoff45s"}'
fi

Set permissions and move the script file to /usr/local/bin

$ chmod u+x ~/turnOffOutlet.sh
$ sudo mv ~/turnOffOutlet.sh /usr/local/bin/

Now would be a good time to test our script, turn on the outlet and run the script. The outlet should turn off after the amount of seconds you set in the delay field.

$ /usr/local/bin/turnOffOutlet.sh

Step 4

Now we create a system service to run our script upon shutdown

$ sudo nano /etc/systemd/system/turnoffoutlet.service

Contents of /etc/systemd/system/turnoffoutlet.service

[Unit]
Description="KP115 outlet control"
Requires=network.target network-online.target
Before=shutdown.target
After=network-online.target
Wants=network-online.target

[Service]
Type=oneshot
RemainAfterExit=true
ExecStart=/bin/true
ExecStop=/usr/local/bin/turnOffOutlet.sh

[Install]
WantedBy=multi-user.target

Run the following commands to enable the new service

$ sudo systemctl daemon-reload
$ sudo systemctl enable turnoffoutlet.service
$ sudo systemctl start turnoffoutlet

And thats it, you're done.

Turn on the outlet and try shutting down your pi.
If all goes well the outlet will turn off after the delay time you set.

$ sudo shutdown -now