Fetch weather forecast from Yr.no on LogicMachine #

Scheduled script #

Make sure that your script does not fetch data too quickly (we recommend at most once in four hours).

Change latitude, longitude, group addresses and group names as needed.

local latitude = 45.921373 -- 'Mandello del Lario'
local longitude = 9.314482 -- 'Mandello del Lario'

function create(config)
  local address = config.address
  local object = grp.find(address)

  if not object then
    grp.create(config)
  end

  return address
end

local status_temp = create({ datatype = dt.float16, address = '33/1/1', name = 'current_temp' })
local status_pressure = create({ datatype = dt.uint16, address = '33/1/2', name = 'current_press' })
local status_humidity = create({ datatype = dt.scale, address = '33/1/3', name = 'current_humid' })
local status_wind_direction = create({ datatype = dt.float16, address = '33/1/4', name = 'current_wind_dir' })
local status_wind_speed = create({ datatype = dt.float16, address = '33/1/5', name = 'current_wind_sp' })
local status_uv_index = create({ datatype = dt.uint8, address = '33/1/6', name = 'current_uv_index' })
local status_feelslike_temp = create({ datatype = dt.float16, address = '33/1/7', name = 'current_feels_temp' })

local status_rain_today = create({ datatype = dt.bool, address = '33/1/8', name = 'rain_today' })
local status_snow_today = create({ datatype = dt.bool, address = '33/1/9', name = 'snow_today' })

local status_min_temp_today = create({ datatype = dt.float16, address = '33/1/10', name = 'today_temp_min' })
local status_max_temp_today = create({ datatype = dt.float16, address = '33/1/11', name = 'today_temp_max' })
local status_min_pressure_today = create({ datatype = dt.uint16, address = '33/1/12', name = 'today_press_min' })
local status_max_pressure_today = create({ datatype = dt.uint16, address = '33/1/13', name = 'today_press_max' })
local status_min_wind_speed_today = create({ datatype = dt.float16, address = '33/1/14', name = 'today_wind_min' })
local status_max_wind_speed_today = create({ datatype = dt.float16, address = '33/1/15', name = 'today_wind_max' })
local status_min_uv_today = create({ datatype = dt.uint8, address = '33/1/16', name = 'today_uv_min' })
local status_max_uv_today = create({ datatype = dt.uint8, address = '33/1/17', name = 'today_uv_max' })

local status_rain_tomor = create({ datatype = dt.bool, address = '33/1/18', name = 'rain_tomor' })
local status_snow_tomor = create({ datatype = dt.bool, address = '33/1/19', name = 'snow_tomor' })

local status_min_temp_tomor = create({ datatype = dt.float16, address = '33/1/20', name = 'tomor_temp_min' })
local status_max_temp_tomor = create({ datatype = dt.float16, address = '33/1/21', name = 'tomor_temp_max' })
local status_min_pressure_tomor = create({ datatype = dt.uint16, address = '33/1/22', name = 'tomor_press_min' })
local status_max_pressure_tomor = create({ datatype = dt.uint16, address = '33/1/23', name = 'tomor_press_max' })
local status_min_wind_speed_tomor = create({ datatype = dt.float16, address = '33/1/24', name = 'tomor_wind_min' })
local status_max_wind_speed_tomor = create({ datatype = dt.float16, address = '33/1/25', name = 'tomor_wind_max' })
local status_min_uv_tomor = create({ datatype = dt.uint8, address = '33/1/26', name = 'tomor_uv_min' })
local status_max_uv_tomor = create({ datatype = dt.uint8, address = '33/1/27', name = 'tomor_uv_max' })

-- mm for next 6 hours
local status_precipitation_amount_6h = create({ datatype = dt.float16, address = '33/1/28', name = 'precipitation_amount_6h' })
-- mm for current day + 3 previous hours
local status_precipitation_amount_today = create({ datatype = dt.float16, address = '33/1/29', name = 'precipitation_amount_today' })

local rain_tod_YR = false        -- is rainy or not (for today)
local snow_tod_YR = false        -- is snowy or not (for today)
local rain_tom_YR = false        -- is rainy or not (for tomorrow)
local snow_tom_YR = false        -- is snowy or not (for tomorrow)

-- current temperature, air pressure, humidity, wind direction and speed
local temperature_YR = -273    -- temperature in degree Celsius
local air_pressure_YR = -1     -- air pressure in hPa
local humidity_YR = -1         -- air humidity in %
local wind_direction_YR = -1   -- wind direction in degrees [0; 360)
local wind_speed_YR = -1       -- wind speed in m/s
local uv_index_YR = -1         -- UV index
local feelslike_temp_YR = -273 -- feels like temperature in degree Celsius
local precipitation_amount_6h = -1 -- participation amount in mm next 6 hours
local precipitation_amount_today = 0 -- participation amount in mm for current day + 3 previous hours

function init_min_max_table() -- initialize table for minimum, maximum temperature, pressure, windspeed
  return {
    min_t = 8000, -- minimum temperature for today
    max_t = -273, -- maximum temperature for today
    min_p = 8000, -- minimum pressure for today
    max_p = -1,   -- maximum pressure for today
    min_w = 8000, -- minimum wind speed for today
    max_w = -1,   -- maximum wind speed for today
    min_uv = 8000, -- minimum UV index
    max_uv = -1,   -- maximum UV index
  }
end

function set_timestamp(day) -- if day = 0 today; if day = 1 tomorrow, if day = 2 day after tomorrow
  local date = os.date('*t')
  date.day = date.day + day
  local time = os.time(date)
  return os.date('%Y-%m-%d', time), date.hour -- timestamp and current hour
end


-- minimum maximum values of temperature, pressure and windspeed
function min_max_temp_press_wind(dat_tab, min_max_tab)
  min_max_tab.min_t = math.min(min_max_tab.min_t, dat_tab.air_temperature or 8000)
  min_max_tab.max_t = math.max(min_max_tab.max_t, dat_tab.air_temperature or -273)
  min_max_tab.min_p = math.min(min_max_tab.min_p, dat_tab.air_pressure_at_sea_level or 8000)
  min_max_tab.max_p = math.max(min_max_tab.max_p, dat_tab.air_pressure_at_sea_level or -1)
  min_max_tab.min_w = math.min(min_max_tab.min_w, dat_tab.wind_speed or 8000)
  min_max_tab.max_w = math.max(min_max_tab.max_w, dat_tab.wind_speed or -1)
  min_max_tab.min_uv = math.min(min_max_tab.min_uv, dat_tab.ultraviolet_index_clear_sky or 8000)
  min_max_tab.max_uv = math.max(min_max_tab.max_uv, dat_tab.ultraviolet_index_clear_sky or -1)

  return min_max_tab
end

function check_for_rain(next1h)
  local is_rainy = false
  local code = ''

  if type(next1h) == 'table' and type(next1h.summary) == 'table' then
    code = next1h.summary.symbol_code or ''
  end

  if code:find('rain') then
    is_rainy = true
  end

  return is_rainy
end

function check_for_snow(next1h)
  local is_snowy = false
  local code = ''

  if type(next1h) == 'table' and type(next1h.summary) == 'table' then
    code = next1h.summary.symbol_code or ''
  end

  if code:find('snow') then
    is_snowy = true
  end

  return is_snowy
end

function calc_heat_index(temperature, humidity)
  if temperature < 26.7 then
    log('for heat_index calculation temperature should be higher than +26.7 Celsius degree')
    return -273
  end

  if humidity < 0 or humidity > 100 then
    log('humidity should be in a range from 0 ... 100%')
    return -273
  end

  local T = temperature
  local H = humidity
  local c_1 = -8.785
  local c_2 = 1.611
  local c_3 = 2.339
  local c_4 = -0.146
  local c_5 = -0.0123
  local c_6 = -0.0164
  local c_7 = 0.00221
  local c_8 = 0.000725
  local c_9 = -0.00000358
  local heat_index = c_1+c_2*T+c_3*H+c_4*T*H+c_5*T*T+c_6*H*H+c_7*T*T*H+c_8*T*H*H+c_9*T*T*H*H

	return heat_index
end


function calc_wind_chill(temperature, wind_speed)
  if temperature > 10 then
    log('temperature should be less than +10.0 Celsius degree')
  	return -273
  end

  if wind_speed < 0 or wind_speed > 49.2 then
  	log('wind speed should be in a range 0 ... 49.2 m/s')
    return -273
  end

  local T_air = temperature -- air temperature Celsius degree

  local a = 0.62 -- coef
  local b = 0.51 -- coef
  local T_1 = 13.1 -- Celsius degree
  local T_2 = 14.6 -- Celsius degree

  local M_0 = 1.3333 -- m/s
  local M = wind_speed -- m/s

  local T_wind_chill

  if M > M_0 then
    T_wind_chill = (a*T_air + T_1) + (b*T_air - T_2)*(M/M_0)^0.16
  else
    T_wind_chill = T_air
  end

  return T_wind_chill
end

function calc_feelslike(temperature, wind_speed, humidity)
  local T_feelslike

  if temperature <= 10.0 then -- if less than 10.0 Celsius degree (or equal) then wind chill
    T_feelslike = calc_wind_chill(temperature, wind_speed)
  elseif temperature >= 26.7 then -- if more than 26.7 Celsius degree (or equal) then heat index
    T_feelslike = calc_heat_index(temperature, humidity)
  else -- other cases just return temperature
    T_feelslike = temperature
  end

  return T_feelslike
end

local min_max_today = init_min_max_table() -- table for minimum maximum temperature, air pressure, wind direction
local min_max_tomor = init_min_max_table() -- table for minimum maximum temperature, air pressure, wind direction

https = require('ssl.https')
json = require('json')
ltn12 = require('ltn12')

args = 'lat=' .. latitude .. '&lon=' .. longitude

url = 'https://api.met.no/weatherapi/locationforecast/2.0/complete?' .. args

mac = 0
io.readfile('/sys/class/net/eth0/address'):gsub('%x%x', function(v)
  mac = mac * 256 + tonumber(v, 16)
end)

response = {}

res, code = https.request({
  url = url,
  protocol = 'tlsv12',
  headers = {
    ['user-agent'] = 'LM ' .. mac
  },
  sink = ltn12.sink.table(response)
})

if res and code == 200 then
  data = json.pdecode(table.concat(response))
else
  log('request error', res, code)
  return
end

if type(data) ~= 'table' then
  log('failed to decode data')
  return
end

timestamp, hour = set_timestamp(0) -- current day

if hour < 10 then
  timestamp_current_hour = timestamp .. 'T0' .. hour .. ':00:00Z' -- time stamp for current hour
else
  timestamp_current_hour = timestamp .. 'T' .. hour .. ':00:00Z'  -- time stamp for current hour
end

--log('timestamp = ' .. timestamp)

timestamp_next = set_timestamp(1) -- timestamp for tomorrow
--log('timestamp_next = ' .. timestamp_next)

--timestamp_after_next = set_timestamp(2) -- timestamp for day after tomorrow
--log('timestamp_after_next = ' .. timestamp_after_next)

--timestamp_after_after = set_timestamp(3) -- timestamp for day after day after tomorrow
--log('timestamp_after_after = ' .. timestamp_after_after)

for i, entry in ipairs(data.properties.timeseries) do
  -- for weather now
  if entry.time == timestamp_current_hour then -- get data only for one hour (current hour)
    current_data = entry.data.instant.details
    if type(current_data) == 'table' then
      temperature_YR = current_data.air_temperature or -273           -- temperature in Celsius degree
      air_pressure_YR = current_data.air_pressure_at_sea_level or -1  -- air pressure in hPa
      humidity_YR = current_data.relative_humidity or -1              -- air humidity in %
      wind_direction_YR = current_data.wind_from_direction or -1      -- wind direction in degrees [0;360)
      wind_speed_YR = current_data.wind_speed or -1                   -- wind speed in m/s
      uv_index_YR = current_data.ultraviolet_index_clear_sky or -1    -- uv index
      feelslike_temp_YR = calc_feelslike(temperature_YR, wind_speed_YR, humidity_YR) -- feels like temperature in Celsius degree
    end

    next_6h = entry.data.next_6_hours.details
    if type(next_6h) == 'table' then
      precipitation_amount_6h = next_6h.precipitation_amount or -1 -- precipitation amount in mm, next 6 hours
    end
  end

  if entry.time:sub(1, #timestamp) == timestamp then -- checks remaining hours + 3 previous hours of current day
  	current_data = entry.data.instant.details
    if type(current_data) == 'table' then
      min_max_today = min_max_temp_press_wind(current_data, min_max_today)
    end

    if rain_tod_YR == false then -- if detected rain does not check for rain
      rain_tod_YR = check_for_rain(entry.data.next_1_hours)
    end

    if snow_tod_YR == false then -- if detected snow does not check for snow
      snow_tod_YR = check_for_snow(entry.data.next_1_hours)
    end

    precipitation_amount_today = precipitation_amount_today + (entry.data.next_1_hours.details.precipitation_amount or 0)
  end

  if entry.time:sub(1, #timestamp_next) == timestamp_next then -- checks 24 hours of next day
    tomor_data = entry.data.instant.details
    if type(tomor_data) == 'table' then
      min_max_tomor = min_max_temp_press_wind(tomor_data, min_max_tomor)
    end

    if rain_tom_YR == false then -- if detected rain does not check for rain
      rain_tom_YR = check_for_rain(entry.data.next_1_hours)
    end

    if snow_tom_YR == false then -- if detected snow does not check for snow
      snow_tom_YR = check_for_snow(entry.data.next_1_hours)
    end
  end
end

-- data for current hour
grp.checkwrite(status_temp, temperature_YR)
grp.checkwrite(status_pressure, air_pressure_YR)
grp.checkwrite(status_humidity, humidity_YR)
grp.checkwrite(status_wind_direction, wind_direction_YR)
grp.checkwrite(status_wind_speed, wind_speed_YR)
grp.checkwrite(status_uv_index, uv_index_YR)
grp.checkwrite(status_feelslike_temp, feelslike_temp_YR)

-- precipitation mm for next 6 hours
grp.checkwrite(status_precipitation_amount_6h, precipitation_amount_6h)

-- precipitation mm for today (remaining day + 3 previous hours)
grp.checkwrite(status_precipitation_amount_today, precipitation_amount_today)

-- data for today: rain, snow; min and max for temperature, pressure, wind
grp.checkwrite(status_rain_today, rain_tod_YR)
grp.checkwrite(status_snow_today, snow_tod_YR)

grp.checkwrite(status_min_temp_today, min_max_today.min_t)
grp.checkwrite(status_max_temp_today, min_max_today.max_t)
grp.checkwrite(status_min_pressure_today, min_max_today.min_p)
grp.checkwrite(status_max_pressure_today, min_max_today.max_p)
grp.checkwrite(status_min_wind_speed_today, min_max_today.min_w)
grp.checkwrite(status_max_wind_speed_today, min_max_today.max_w)
grp.checkwrite(status_min_uv_today, min_max_today.min_uv)
grp.checkwrite(status_max_uv_today, min_max_today.max_uv)


-- data for tomorrow: rain, snow; min and max for temperature, pressure, wind
grp.checkwrite(status_rain_tomor, rain_tom_YR)
grp.checkwrite(status_snow_tomor, snow_tom_YR)

grp.checkwrite(status_min_temp_tomor, min_max_tomor.min_t)
grp.checkwrite(status_max_temp_tomor, min_max_tomor.max_t)
grp.checkwrite(status_min_pressure_tomor, min_max_tomor.min_p)
grp.checkwrite(status_max_pressure_tomor, min_max_tomor.max_p)
grp.checkwrite(status_min_wind_speed_tomor, min_max_tomor.min_w)
grp.checkwrite(status_max_wind_speed_tomor, min_max_tomor.max_w)
grp.checkwrite(status_min_uv_tomor, min_max_tomor.min_uv)
grp.checkwrite(status_max_uv_tomor, min_max_tomor.max_uv)