Example: Fetch Yahoo weather forecast

KNX specific configuration in Logic Machine

• Connect to Logic Machine (Logic Machine) with default access parameters (IP: 192.168.0.10; login/password: admin/admin)

Create “Weather data Yahoo” resident script

• In scripting tab click on the Resident button, then Add new script. In this example the script will be run every minute

• After you have saved the script, click on the icon in Editor column to enter into scripting redactor. The script is fetching 5 variables from Yahoo for Riga city – current temperature, current condition, forecast condition for tomorrow, forecast min and max temperatures for tomorrow – and storing them into KNX group addresses.

• After first time the script is run the new group addresses are added (if not added before) into Objects menu. You can set the respective names for these objects.

• You can add these objects into your visualization map with respective icons. Or you can use these objects to preset HVAC system accordingly to weather.

Source code

require('json')
 
local city = 854823
local cmd, data, forecast
 
cmd = 'wget -q -O - "http://weather.yahooapis.com/forecastjson?w=' .. city .. '&u=c" 2>/dev/null'
data = io.readproc(cmd)
if not data then
  alert('Weather: cannot get data')
  return false
end
 
data = json.pdecode(data)
if not data then
  alert('Weather: cannot parse data')
  return false
end
 
grp.write('5/1/1', data.condition.text, dt.string)
grp.write('5/1/2', data.condition.temperature, dt.float16)
 
forecast = data.forecast[2]
grp.write('5/1/3', forecast.condition, dt.string)
grp.write('5/1/4', forecast.low_temperature, dt.float16)
grp.write('5/1/5', forecast.high_temperature, dt.float16)