hostname = os.getenv("COLLECTD_HOSTNAME") 
if hostname==nil then hostname="undefined-hostname" end 
interval = os.getenv("COLLECTD_INTERVAL") 
if interval==nil then interval=10 end 

rserial=io.open("/dev/ttyACM0","r") 
wserial=io.open("/dev/ttyACM0","w") 
rserial:flush() 

while true do 
  wserial:write(".") 
  tstart = os.time() 
  repeat 
    line=rserial:read() 
    line=string.gsub(line,"\r$","") 

    temp = nil 
    humidity = nil 
    temp, humidity = string.match(line, 'DHT%s+([%.,%d]+)%s+([%.,%d]+)') 
    if temp ~= nil and humidity ~= nil then 
      print("PUTVAL "..hostname.."/dht/temperature-temperature interval="..interval.." N:"..temp) 
      print("PUTVAL "..hostname.."/dht/humidity-humidity interval="..interval.." N:"..humidity) 
      line="" 
    end 

    romid = nil 
    temp = nil 
    romid, temp = string.match(line, '(%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x%x)%s+([%.,%d]+)') 
    if romid ~= nil and temp ~= nil then 
      print("PUTVAL "..hostname.."/onewire/"..romid.."-temperature interval="..interval.." N:"..temp) 
    end 

  until line=="EOF" 

  towait = interval - os.difftime(os.time(),tstart) 
  if towait>0 then 
    os.execute("sleep "..tonumber(towait)) 
  end 

end