Get prices from webpage via Excel

[Jørn]

Allright, cleaned that up and added some other (i think) useful functions  (:
Also put all configurable parameters easily available at the top of the script.

Code:

output = '1/1/1' -- output group address, 14 byte
city = 1    -- 1 = Oslo, 2 = Kr.sand, 3 = Bergen, 4 = Tr.heim, 5 = Molde, 6 = Tromsø
timeshift = 1    -- 0= Last hour, 1 = current hour, 2 = next hour
scale = 1    -- 1 = MWh price, 1000 = KWh price.


-- Script for writing hourly power prices from nordpool to knx object.
require('json')
require('ssl.https')

now = os.date('*t')
pickhour = now.hour + timeshift
param = os.date('%d-%m-%Y', os.time(date))

res = ssl.https.request('https://www.nordpoolgroup.com/api/marketdata/page/23?currency=NOK&endDate=' .. param)
values = {}

if res then
 res = json.pdecode(res)

 if type(res) == 'table' then
   for _, row in ipairs(res.data.Rows) do
     cols = row.Columns
     value = cols[ city ].Value:gsub(',', '.')
     values[ #values + 1 ] = tonumber(value)
   end
 end
end

grp.write(output, values[pickhour] / scale)