print(" ")
print("Bgr init.lua v1.2")
_, reset_reason = node.bootreason()
print("Bootreason = " .. reset_reason)

appfilename = "app.lc"

print("Checking if " .. appfilename .. " exists")
if file.exists(appfilename) then
    --appfile exists
    print(appfilename .. " exists!")
    if reset_reason == 5 then 
        print("It was wake from deep sleep, no waiting, launching " .. appfilename)
        dofile (appfilename)
    else
        print("It wasnt wake from deepsleep, wait 10sec and then run " .. appfilename)    
        tmr.alarm(1,10000,0,function()
            dofile (appfilename)
        end)
    end

else
    --appfile does not exists
    print(appfilename .. " does not exist, nothing to launch, quitting...")
end

address = 0x4F  -- LM75 I2C Address
temp_reg = 0     -- temp reg for normal operation
temp_reg_shutdown = 1 --temp reg pro shutdown
bus = 0              -- I2C bus
sda, scl = 3, 4   -- Used pins for SDA (3=gpio0) and SCL (4=gpio2)
sleeptime = 60000000 --cas mezi odesilanim dat v us

function init_I2C(sda, scl)
    i2c.setup(bus, sda, scl, i2c.SLOW)
end 

function sleep()
  --print debug info
  print("going to sleep for " .. sleeptime/1000000 .. "s")

  --disconnect from broker
  m:close()

  --shutdown lm75
  i2c.start(bus)      
  i2c.address(bus, address, i2c.TRANSMITTER)
  i2c.write(bus, temp_reg_shutdown)
  i2c.stop(bus)

  node.dsleep(sleeptime, 1)

end

function read_temp() 
  i2c.start(bus)      
  i2c.address(bus, address, i2c.TRANSMITTER)
  i2c.write(bus, temp_reg)
  i2c.stop(bus)

  i2c.start(bus)
  i2c.address(bus, address, i2c.RECEIVER)
  t=i2c.read(bus, 2)
  i2c.stop(bus)

  h,l = string.byte(t,1,2)

  if h > 127 then 
    --zaporne teploty
    h = h - 255 
    l=(bit.band(bit.bnot(bit.rshift(l, 5))+1, 7))*125

    --zaokrouhlit desetiny na jedno misto
    l = ((l + 50) / 100)

    if h == 0 then
        --zaporne od 0 do -0.9999
        temp=string.format("-%d.%d", h,l)
    else
        --zaporne pod -1
        temp=string.format("%d.%d", h,l)
    end

  else
    -- kladne teploty
    l=(bit.band(bit.rshift(l, 5), 7))*125  

    --zaokrouhlit desetiny na jedno misto
    l = ((l + 50) / 100)

    temp=string.format("%d.%d", h,l)
  end

  return temp

end

-- init mqtt client with keepalive timer 120sec
m = mqtt.Client("some-cli-ID", 120, "broker-username", "broker-password")

m:on("offline", function(client) print ("offline") end)

function connectbroker (b)
    b:connect("your-broker-server", 8883, 1, function(client) 
                                        print("connected to broker")
                                        print ("temp: " .. t .. "C")
                                        m:publish("espthermo/temp",t,0,0, function(client) 
                                            print("temp ack")
                                            print ("battery: " .. battvolt .. "mV")
                                            m:publish("espthermo/batt",battvolt,0,0, function (client)
                                                print ("voltage ack")
                                                wifirssi=wifi.sta.getrssi()
                                                print ("wifi rssi: " .. wifirssi .. "dBm")
                                                m:publish("espthermo/wifi",wifirssi,0,0, function (client)
                                                    print("rssi ack")
                                                    sleep() 
                                                    end)
                                                end)
                                            end)
                                        end)
end

print(" ")
init_I2C(sda, scl)
battvolt=(adc.readvdd33(0))
t=read_temp()
print("Connecting to WiFi")
wifi.sta.eventMonReg(wifi.STA_GOTIP, function() 
    print("got IP:", wifi.sta.getip())
    connectbroker (m)
    end)

wifi.sta.eventMonStart()

wifi.sta.connect()

-- timer to go sleep after 10s even if cant send data to save battery
tmr.alarm(1,10000,0,function()
    print ("timeout sending data, turning off to save battery")
    sleep()
end)

-- wifi mode
wifi.setmode(wifi.STATION)

-- band
wifi.setphymode(wifi.PHYMODE_G)

-- wifi network ssid / pwd + save
station_cfg={}
station_cfg.ssid="your-ssid"
station_cfg.pwd="wifi-password"
station_cfg.save=true
station_cfg.auto=true
wifi.sta.config(station_cfg)

-- disable autoconnect
wifi.sta.autoconnect(0)

-- init adc to read VDD33
adc.force_init_mode(adc.INIT_VDD33)

-- restart to apply
node.restart()