Add option for individual outlet control on HS300 and HS303 power strips

[AMDHome]

This pull requests adds some documentation and basic code to modify the commands and show how to control individual outlets on a TP-Link Kasa power strip.

Overview

As it is, this script can control power strips as a single entity. All switches on/off, timer/schedule set for all outlets, etc.
By adding a specially formatted piece of data you can control outlets individually.

Existing commands:

1. {"system":{"set_relay_state":{"state":1}}}
2. {"system":{"set_relay_state":{"state":0}}}

New commands for HS300/303

1. {"context":{"child_ids":["8006...E101"]}, "system":{"set_relay_state":{"state":1}}}
2. {"context":{"child_ids":["8006...E101"]}, "system":{"set_relay_state":{"state":0}}}

child_ids

Child IDs are 42 character long Hexadecemal strings. You can get these values by running the info command on the power strip.

For instance, I have the HS303 power strip and when I run {"system":{"get_sysinfo":{}}} it will return the following JSON:

{
  "system": {
    "get_sysinfo": {
      "sw_ver": "1.0.9 Build 191031 Rel.095941",
      "hw_ver": "1.0",
      "model": "KP303(US)",
      "deviceId": "8006243B...AAE1",
      .
      .
      .
      "led_off": 0,
      "children": [
        {
          "id": "8006243B...AAE100",
          "state": 1,
          "alias": "Do not turn off!!!",
          "on_time": -3372260,
          "next_action": {
            "type": -1
          }
        },
        {
          "id": "8006243B...AAE101",
          "state": 0,
          "alias": "Plug 2",
          "on_time": 545,
          "next_action": {
            "type": -1
          }
        },
        {
          "id": "8006243B...AAE102",
          "state": 1,
          "alias": "Heat Pad",
          "on_time": 36062,
          "next_action": {
            "type": -1
          }
        }
      ],
      "child_num": 3,
      "ntc_state": 0,
      "err_code": 0
    }
  }
}

Some lines have been omitted to shorten the length

If you look under "system" > "get_sysinfo" > "children" you can see the ID and alias for each of the outlets on your power strip.

These child IDs should be just the deviceId + a 2 digit number representing the position of the outlet on your device (00 - 06 or 00 - 02 depending on which one you have)

Multiple Control

You can actually control multiple outlets at once by specifying multiple IDs in the command JSON array.
Only outlet 1: {"context":{"child_ids":["8006...E101"]}, "system":{"set_relay_state":{"state":0}}}
Only outlet 1 and 2: {"context":{"child_ids":["8006...E101","8006...E102"]}, "system":{"set_relay_state":{"state":0}}}

[draco2003]

@AMDHome, Have you been able to set multiple child_ids at the same time or does it just change the state of the first child_id in the list?

[AMDHome]

I haven't used it in a while since the project I used this for ended, but if you craft the json by hand using the -j option you can add as many outlets as the strip has to the "child_id" array.

If you are just using the -o flag that I implemented here as proof of concept, then no. You can only change one outlet at a time with the -o flag.

You could change the code to allow for multiple -o flags and put them all in the "child_id" array in the json, but I was lazy when writing it and didn't do that