如何在Ubuntu下用Ruby控制灯

最近我获得了Elgato Key Light。它是一个WiFi可控的LED照明面板。

该面板使用160个LED，提供高达2800流明的亮度和2900-7000K的色彩范围。虽然你可以从移动设备上控制它，但直接从外壳上进行控制使整个体验更加方便。

Key Light官方不支持Linux，但它使用ESP32，而且它确实运行一个不受保护的HTTP服务器，接受JSON命令。你不仅可以打开和关闭它，还可以通过简单的JSON请求来调整光温和亮度。

下面是我用来控制我的灯的代码，是用Ruby编写的。

#!/usr/bin/env ruby

require 'uri'
require 'net/http'
require 'json'
require 'yaml'

# Set your lights IPs
LIGHTS = %w[
  192.168.0.199
]

COMMAND = ARGV[0]
DETAIL1 = ARGV[1].to_i
DETAIL2 = ARGV[2].to_i

# Sends a json request to a given elgato light
def dispatch(ip, payload, endpoint, method)
  uri = URI("http://#{ip}:9123/elgato/#{endpoint}")
  req = method.new(uri)
  req.body = payload.to_json

  res = Net::HTTP.start(uri.hostname, uri.port) do |http|
    http.request(req)
  end

  puts res.body
end

def on(light_ip)
  dispatch(
    light_ip,
    { 'numberOfLights': 1, 'lights': [{ 'on': 1 }] },
    'lights',
    Net::HTTP::Put
  )
end

def off(light_ip)
  dispatch(
    light_ip,
    { 'numberOfLights': 1, 'lights': [{ 'on': 0 }] },
    'lights',
    Net::HTTP::Put
  )
end

def temperature(light_ip, value)
  raise "Needs to be between 143 and 344, was: #{value}" if value < 143 || value > 344

  dispatch(
    light_ip,
    { 'numberOfLights': 1, 'lights': [{ 'on': 1, 'temperature': value }] },
    'lights',
    Net::HTTP::Put
  )
end

def brightness(light_ip, value)
  raise "Needs to be between 3 and 100, was: #{value}"  if value < 3 || value > 100

  dispatch(
    light_ip,
    { 'numberOfLights': 1, 'lights': [{ 'on': 1, 'brightness': value }] },
    'lights',
    Net::HTTP::Put
  )
end

def info(light_ip)
  dispatch(
    light_ip,
    {},
    'accessory-info',
    Net::HTTP::Get
  )
end

def command(command, light_ip)
  case command
  when 'on'
    on(light_ip)
  when 'off'
    off(light_ip)
  when 'temperature'
    temperature(light_ip, DETAIL1)
  when 'brightness'
    brightness(light_ip, DETAIL1)
  when 'theme'
    temperature(light_ip, DETAIL1)
    brightness(light_ip, DETAIL2)
  when 'info'
    info(light_ip)
  else
    raise "Unknown COMMAND #{COMMAND}"
  end
end

LIGHTS.each { |light_ip| puts command(COMMAND, light_ip) }

你可以把这段代码放在/usr/local/bin ，在elgato 名下，有可执行的权限，然后你就可以。

elgato on # turn your lights on
elgato off # turn your lights off
elgato info # get info on your lights
elgato brightness 50 # set brightness to 50%
elgato temperature 280 # make  light temperature quite warm