ESP8266_DS18B20/server.lua

-- vim : set autoindent expandtab tabstop=2 shiftwidth=2

cs=coap.Server() -- Lance le serveur CoAP
cs:listen(5683)  -- sur le port 5683

pin = 3
ow.setup(pin) -- DS18B20 sur le pin 3


function get_data(nbre)
  capteurs = {}
  temperatures = {}
  print("Cherche les capteurs : ")
  print(nbre)
  addr = ow.reset_search(pin)
  for ds = 1, nbre, 1 do
    addr = ow.search(pin)
    if addr == nil then
      pint("Pas de capteurs")
    else
      print(addr:byte(1,8))
      local crc = ow.crc8(string.sub(addr,1,7))
      if crc == addr:byte(8) then
        if (addr:byte(1) == 0x10) or (addr:byte(1) == 0x28) then
          print("Device is a DS18S20 family device.")
          table.insert(capteurs, addr)
        end
      end
    end
  end
  ow.reset(pin)
  for _, addr in ipairs(capteurs) do
    tmr.create():alarm(1500, tmr.ALARM_SINGLE, startup)
    ow.reset(pin)
    ow.select(pin, addr)
    ow.write(pin, 0x44, 1)
    tmr.create():alarm(1500, tmr.ALARM_SINGLE, startup)
    ow.reset(pin)
    ow.select(pin, addr)
    ow.write(pin,0xBE,1)
    local data = ow.read_bytes(pin, 9)
    local crc = ow.crc8(string.sub(data,1,8))
    if crc == data:byte(9) then
      local t = (data:byte(1) + data:byte(2) * 256) * 625
      local sgn = t<0 and -1 or 1
      local tA = sgn*t
      local t1 = math.floor(tA / 10000)
      local t2 = tA % 10000
      temperature = (sgn<0 and "-" or "")..t1.."."..t2
      print("temperature ="..temperature.." C")
      local addr1 = addr:byte(1)
      local addr2 = addr:byte(2)
      local addr3 = addr:byte(3)
      local addr4 = addr:byte(4)
      local addr5 = addr:byte(5)
      local addr6 = addr:byte(6)
      local addr7 = addr:byte(7)
      local addr8 = addr:byte(8)
      local addr0 = string.format("%s:%s:%s:%s:%s:%s:%s:%s", addr1, addr2, addr3, addr4, addr5, addr6, addr7, addr8)
      result = addr0.."="..temperature
      table.insert(temperatures, result)
    end
  end
  data = table.concat(temperatures,";")
  print("data :")
  print(data)
  return data
end

cs:func("get_data")