mqtt1.lua

local srv = "http://91.226.122.210:15781"
local mon = peripheral.wrap("top")
term.redirect(mon)
term.clear()
term.setCursorPos(1,1)
local mag = peripheral.wrap("left")

term.setTextColour(colors.black)
term.setBackgroundColor(colors.red)
print("Access card required")
local msevt, token = os.pullEvent("mag_swipe")
term.clear()
term.setCursorPos(1,1)
term.setTextColor(colors.white)
term.setBackgroundColor(colors.black)
term.clear()

local interval = 60

local MAXATTEMPTS = 12
local attempt = 0

local topics = {"wrkshp/room/t0", "wrkshp/room/t1"}

while not http.checkURL(srv) do
    print("Server unavailable. Retrying...")
    attempt = attempt + 1
    if attempt > MAXATTEMPTS then
        print("Connection failed")
        os.exit()
    end
    sleep(10)
end

-- print("Server alive")
while true do

for i=1, #topics do
    topic = topics[i]
    req, err = http.get(srv .. "/sub/" .. topic .. "?token=" .. token)
    if not req then error(err) end
    result = tostring(req.readAll())
    print(topic .. ": " .. result)
    req.close()
end

sleep(interval)
term.clear()
term.setCursorPos(1,1)

end