Wake TV when MacOS wakes from sleep (Hammerspoon)

waketv.lua

local tv_input = "HDMI_2" -- Input to which your Mac is connected
local mac_address = "80:5B:65:6D:AF:D4"
local switch_input_on_wake = true -- Switch input to Mac when waking the TV
local prevent_sleep_when_using_other_input = true -- Prevent sleep when using other input (ie: watching TV)
local debug = false  -- If you run into issues, set to true to enable debug messages

-- You likely will not need to change anything below this line
local tv_name = "MyTV" -- Name of your TV, set when you run `lgtv auth`
local connected_tv_identifiers = {"LG TV", "LG TV SSCR2"} -- Used to identify the TV when it's connected to this computer
local screen_off_command = "off" -- use "screenOff" to keep the TV on, but turn off the screen.
local lgtv_path = "/opt/lgtv-venv/bin/lgtv" -- Full path to lgtv executable
local lgtv_cmd = lgtv_path.." "..tv_name
local app_id = "com.webos.app."..tv_input:lower():gsub("_", "")
local lgtv_ssl = true -- Required for firmware 03.30.16 and up. Also requires LGWebOSRemote version 2023-01-27 or newer.

function lgtv_current_app_id()
  local foreground_app_info = exec_command("getForegroundAppInfo")
  foreground_app_info = string.match(foreground_app_info, '^%b{}')
  foreground_app_info = hs.json.decode(foreground_app_info)
  return foreground_app_info["payload"]["appId"]
end

function tv_is_connected()
  for i, v in ipairs(connected_tv_identifiers) do
    if hs.screen.find(v) ~= nil then
      return true
    end
  end

  return false
end

function dump_table(o)
  if type(o) == 'table' then
    local s = '{ '
    for k,v in pairs(o) do
      if type(k) ~= 'number' then k = '"'..k..'"' end
      s = s .. '['..k..'] = ' .. dump_table(v) .. ','
    end
    return s .. '} '
  else
    return tostring(o)
  end
end

function exec_command(command)
  if lgtv_ssl then
    command = command.." ssl"
  end

  command = lgtv_cmd.." "..command

  if debug then
    print("Executing command: "..command)
  end

  return hs.execute(command)
end

if debug then
  print ("TV name: "..tv_name)
  print ("TV input: "..tv_input)
  print ("LGTV path: "..lgtv_path)
  print ("LGTV command: "..lgtv_cmd)
  print ("SSL: "..tostring(lgtv_ssl))
  print ("App ID: "..app_id)
  print (exec_command("swInfo"))
  print (exec_command("getForegroundAppInfo"))
  print("Connected screens: "..dump_table(hs.screen.allScreens()))
  print("TV is connected? "..tostring(tv_is_connected()))
end

watcher = hs.caffeinate.watcher.new(function(eventType)
  if debug then print("Received event: "..eventType) end

  if not tv_is_connected() then
    if debug then print("TV is not connected. Skipping.") end
    return
  end

  if (eventType == hs.caffeinate.watcher.screensDidWake or
      eventType == hs.caffeinate.watcher.systemDidWake or
      eventType == hs.caffeinate.watcher.sessionDidBecomeActive or
      eventType == hs.caffeinate.watcher.screensDidUnlock) then

    exec_command("on") -- wake on lan
    exec_command("screenOn") -- turn on screen
    hs.execute("/opt/homebrew/bin/wakeonlan "..mac_address)
    if debug then print("TV was turned on") end

    if lgtv_current_app_id() ~= app_id and switch_input_on_wake then
      exec_command("startApp "..app_id)
      if debug then print("TV input switched to "..app_id) end
    end
  end

  if (eventType == hs.caffeinate.watcher.screensDidSleep or
      eventType == hs.caffeinate.watcher.systemWillPowerOff) then

    if lgtv_current_app_id() ~= app_id and prevent_sleep_when_using_other_input then
      if debug then print("TV is currently on another input ("..current_app_id.."). Skipping powering off.") end
      return
    end

    -- This puts the TV in standby mode.
    -- For true "power off" use `off` instead of `screenOff`.
    exec_command(screen_off_command)
    if debug then print("TV screen was turned off with command `"..screen_off_command.."`.") end
  end
end)
watcher:start()

This extends the original script by @cmer so that it:

1. Turns the TV off when the system sleeps or powers off
2. Switches the TV input to the value you have specified in the script's tv_input variable on wake. This is useful for when the last time you used the TV you were on a different input than the one your computer is connected to

You'll need to install the required dependencies for this to work, and @tonycassara has documented those steps here.

Wait you're setting the input before turning on the TV? Does that work? Maybe in "Always Ready" mode but I wonder if it does if it's not in that mode...

Another thought: I don't have time currently to test but I suspect that wakeonlan works regardless of Always Ready and the lgtv MyTV on works solely in Always Ready mode.

Nice catch on that. I had an older version of this saved in the gist from when I was testing things out trying to find the culprit of the screen turning on right after powering off. Just updated it to properly put the wakeonlan as the first command.

I actually don't have Always Ready on, and I'm able to use both wakeonlan as well as lgtv MyTV on to turn the TV on from powered on state. Seems like lots of commands will turn the TV on, including the lgtv MyTV off command surprisingly.

Interesting so the TV is always on in some way, makes sense with the need for the IR receiver to work, there must be other parts also on including the part that lets you connect via CLI!